After the end of the very successful operation of the TESLA Test Facility Phase I in November 2002, the modification of TTF into a VUV-FEL user facility took place during the year 2003. The injector complex was completely modified. Presently 5 cryomodules have been installed. For bunch length measurements there is a special S-band structure driven by a SLAC 5045 Klystron and an Electro-Optical-Sampling Experiment. Six undulator modules of 30 m total length have been installed. In one cavity of the first module an accelerating gradient of 35 MV/m with beam could be demonstrated. The last two modules have been operated up to the average gradient of 25 MV/m. Emittance measurements show values near 2 pi mm mrad. In January 2005 first successful lasing of the SASE FEL was observed at 32 nm wavelength. This is the shortest wavelength achieved with a FEL so far and the first step to a user facility designed for wavelengths down to 6 nm. By May photon pulses with the peak energy of 20 μJ and average energies around 5 μJ had been produced during many runs. The corresponding peak power of the short pulses of 25 fs FWHM was at the Gigawatt level. First user experiments are foreseen for August 2005.

This paper will address the issues of designing the large accelerator project ILC which is proposed to be the next linear collider facility of global extent, Subjects to be covered are: technological challenges, global organisation scheme, required resources, realisation perspectives and road map.

In the context of a collaboration between LAL (Orsay) and DESY (Hamburg) a programme of development and tests of proto-type power couplers for superconducting cavities is underway in Orsay. Such couplers need to be developed for linear accelerators which require high gradient superconducting cavities, such as the European X ray Free Electron Laser or the International Linear Collider (ILC) project. We will describe the technical demands which have to be met to build such couplers and will present proto-type designs which are intended to meet these demands, taking the ILC as an example. A description of the infra-structure necessary for the coupler development will also be given along with first high power tests results on a series of power couplers built in industry.

The requirements for RF Control Systems for the European X-FEL are not only defined in terms of the quality of field control but also with respect to operability, availability, and maintainability of the RF System, and the interfaces to other subsystems. The field control of the vector-sum of many cavities driven by one klystron in pulsed mode at high gradients is a challenging task since severe Lorentz force detuning, microphonics and beam induced field errors must be suppressed by several orders of magnitude. This is accomplished by a combination of local and global feedback and feedforward control. Sensors monitor individual cavity probe signals, and forward and reflected wave as well as the beam properties including beam energy and phase while actuators control the incident wave of the klystron and individual cavity resonance frequencies. The operability of a large llrf system requires a high degree of automation while the high availability requires robust algorithms, redundancy, and extremely reliable hardware. The maintenance of the llrf demands sophisticated on-line diagnostics for the llrf subsystems to minimize downtime.

This invited talk describes spectroscopic studies of high-current plasma discharges within PF- and RPI-type facilities, used for basic and application-oriented research. Particular attention is paid to measurements of temporal changes of spectral lines from working gases and impurities. Time-resolved spectral measurements were carried out by means of a Mechelle(R)900 spectrometer, operating in the wavelength range from about 200 nm to 1100 nm, with exposition times varied from 100 ns up to 50 ms. That spectrometer was equipped with a cooled CCD camera coupled with a PC and GRAMS-32(R) software. Spectroscopic studies of the deuterium Balmer-lines and some impurity lines, as observed within the PF-360 experiment, are presented and discussed. Estimates of temporal changes in the electron concentration and temperature are given. Measurements of temporal changes in the emission of the deuterium- and impurity-lines emitted from a mega-joule PF-1000 facility are also described. Capabilities of optical techniques to study the interaction of PF discharges with different targets are discussed. Time-resolved spectroscopic studies of plasma discharges within the RPI-IBIS facility, used for material engineering, are also presented. Optical spectra, as recorded for different operational modes, are compared. The use of spectroscopic techniques to study the interaction of pulsed plasma-ion streams with different materials is considered. The presented results of research on dynamics of pulsed plasma streams (produced in different experimental facilities) as well as the described optical diagnostic techniques are important not only for basic physical studies but also for application-oriented research.

The research potential offered by synchrotron radiation sources is largely limited by lack of adequate detectors. This is to some extent true for existing synchrotron radiation sources while for third generation synchrotron radiation sources being developed this is a primary problem. New research areas in life, physical and material sciences demand new detectors suitable for time resolved high resolution imaging and with spectroscopic properties. This paper presents an overview of trends and recent achievements in advanced detector technologies developed over last decade for high energy perticle physics experiments. The detector requirements for instrumentation of synchrotron radiation experiments are discussed. The basic technologies of high-resolution position sensitive detectors, silicon strip detectors and hybrid pixel detectors are reviewed. Fundamental limitations and perspectives of these detector technologies are discussed.

The paper describes efforts of four institutions which are engaged in the realization of the Work Package 4 (Thin Film Cavity Production) of the Joint Research Activity (JRA-1) within a frame of the Coordinated Accelerator Research in Europe (CARE) program. JRA-1 is aimed at developing superconducting RF technology, mainly methods for producing superconducting Nb coated copper cavities which might ensure higher accelerating fields, lower RF losses and considerable reduction of costs, as compared with the present state of art. WP4 is thus focused on the development of a new method to produce thin Nb-coatings by means of arc discharges performed under ultra-high vacuum (UHV) conditions.

The paper presents a flexible electronic tool for VXI register-based device development. Its prototype has been designed on a breadboard containing a one FPGA chip. The most of logic needed is described in a VHDL code which allows its easy updating. A resonance cavity controller is an application example of the tool in question.

The UV Free-Electron Laser (UVFEL) [1], The X-Ray Free-Electron Laser (XFEL) [2] and The International Linear Accelerator (ILC) [9] projects will require phase synchronization of various RF frequency subsystems on kilometer distances with accuracy better than 1ps. To fulfill these requirements, a phase reference distribution system concept was proposed and a prototype was developed for tests in the TESLA Test Facility 2 (TTF2). An important part of the phase reference system is the fiber-optic phase stable, long distance link described in this paper. An interferometrical scheme with feedback on phase, suppressing long term phase drifts induced by temperature changes was developed and tested in laboratory and under accelerator conditions. A motorized optical delay line was used in the system to compensate for phase errors. Described are error considerations and most important project issues like the hardware development and the real time phase controller software. The presented measurement results satisfy the design requirements. Experience gained during the experiments yielded proposals for system improvements.

Upcoming Low Level Radio Frequency (LLRF) systems for particle accelerators are facing manifold challenges. Special purpose machines like the X-Ray Free Electron Laser (XFEL) demand for field stabilities of 0.01% in amplitude and 0.01° in phase for the pulsed operation of superconducting, high-Q resonators. Due to the large number of parameters in a LLRF systems, automated procedures for parameter optimization will be essential. Apart from the field stability, manageability is an important topic. The International Linear Collider (ILC) will exceed the number of 20000 superconducting resonators and several hundred LLRF control loops. It is clear, that automation for this enormous amount of LLRF stations is inevitable. This document describes a systematic approach to implement several automation tasks using the technique of finite state machines (FSM). It is general enough to be applicable on various types of accelerators. A prototype of such an implementation is currently tested at the VUV-FEL at DESY, Hamburg. Some test results will be presented.

The paper describes design, construction and initial measurements of an eight channel electronic LLRF device predicted for building of the control system for the VUV-FEL accelerator at DESY (Hamburg). The device, referred in the paper to as the SIMCON 3.0 (from the SC cavity simulator and controller) consists of a 16 layers, VME size, PCB, a large FPGA chip (VirtexII-4000 by Xilinx), eight fast ADCs and four DACs (by Analog Devices). To our knowledge, the proposed device is the first of this kind for the accelerator technology in which there was achieved (the FPGA based) DSP latency below 200 ns. With the optimized data transmission system, the overall LLRF system latency can be as low as 500 ns. The SIMCON 3.0 sub-system was applied for initial tests with the ACC1 module of the VUV FEL accelerator (eight channels) and with the CHECHIA test stand (single channel), both at the DESY. The promising results with the SIMCON 3.0 encouraged us to enter the design of SIMCON 3.1 possessing 10 measurement and control channels and some additional features to be reported in the next technical note. SIMCON 3.0 is a modular solution, while SIMCON 3.1 will be an integrated board of the all-in-one type. Two design approaches - modular and all-in-one, after branching off in this version of the SIMCON, will be continued.

The digital control of the TESLA (TeV-Energy Superconducting Linear Accelerator) resonator is presented. The laboratory setup of the CHECHIA cavity in DESY-Hamburg has been driven by the FPGA (Field Programmable Gate Array) technology system. This experiment focused attention to the general recognition of the cavity features and projected control methods. The electrical model of the resonator is taken as a consideration origin. The calibration of the signal channel is considered as a key preparation for an efficient cavity driving. The identification of the resonator parameters is confirmed as a proper approach for the required performance: driving on resonance during filling and field stabilization during flattop time with reasonable power consumption. The feed-forward and feedback modes were applied successfully for the CHECHIA cavity driving. Representative results of experiments are presented for different levels of the cavity field gradient.

The paper concerns frequency conversion circuits of electromagnetic field stabilization system in superconductive cavity of linear accelerator. The stabilization system consists of digital part (based on FPGA) and analog part (frequency conversions, ADC/DAC, filters). Frequency conversion circuit is analyzed. The main problem in the frequency conversion for the stabilization system are: linearity of conversion and stability. Also, second order problems are subject of analysis: control of local oscillator parameters and fluctuation of actuated signal (exposing conversion). The following work was done: analysis of individual stage parameters on field stability and external influence, simulation. The work was closed with conclusions of the major frequency conversion parameters for field stabilization. The results have been applied for field stabilization system (RF Feedback System) in TESLA Test Facility 2 and preliminary research on X-Ray Free Electron Laser.

FPGA based cavity simulator and controller is the next generation control system dedicated for high performance, low latency control algorithm development and implementation. The usage of FPGA technology gives users possibility to create many devices on one board and easy exchange, modify or improve VHDL programmed algorithms. In order to provide the full functionality of the system to the user, and meet the requirements of flexibility and extensibility, an appropriate control software is needed. This paper describes the idea and implementation of control environment dedicated for FPGA based devices. As an example of implementation, two control environments have been implemented; the laboratory software based on Matlab, and the application for accelerator operation using DOOCS environment.

This document describes aspects of creating software for communication with hardware, especially with FPGA based systems. Features unique for FPGA systems are compared with features of the traditional electronic systems. There are discussed topics like hardware interface definition, or address space description. Connecting client application is shown with Matlab as an example. Solutions with FPGA and embedded processors are discussed.

The Application Specific Integrated Circuits (ASICs) are widely used for the detector readout in the High Energy Physics (HEP) environment. The ASICs have to work in high radiation environment and provide the basic parallel signal processing from a huge number of detector channels, including substantial data compression. The reliability of the ASICs is a critical issue for the data taking eficiency of the whole system. In the paper the examples of several ASIC design blocks are given with a special focus on the features providing reliability in radiation environment. The problems of the architecture choice, ASIC synchronization, and redundancy is discussed in detail. These aspects of design will be presented on the example of two chips, ABCD and DTMROC dedicated to the one of the general purpose experiments on Large Hadron Collider, ATLAS. The ABCD is the ASIC for the readout of the Semiconductor Tracker (SCT) detector designed using the 0.8 μm BiCMOS technology, and the DTMROC is the readout chip for the Transition Radiation Tracker (TRT) detector, designed using 0.25 μm CMOS technology.

Electronic components during High Energy Physics experiments are exposed to high level of radiation. Radiation environment causes many problems to electronic devices. The goal of several experiments done at DESY (Deutsches Elektronen Synchrotron, Hamburg) was to investigate nature of irradiation effects, caused damages and possible techniques of mitigation. One of aspects of experiments is radiation measurements. The propositions of building radiation monitoring system, using different semiconductor components, are presented. Second aspect is radiation tolerance. Different electronic devices were tested: FPGA chips, CCD sensors, bubble dosimeters and LED diodes. Components were irradiated in TESLA Test Facility 2 tunnel and in laboratory using ²⁴¹Am/Be neutron source. The results of experiments are included and discussed.

Nano-resolution imaging techniques such as scanning tunnelling microscopy (STM) and atomic force microscopy(AFM) are well-know in surface science. However, a scanning helium atom microscope, where a focused beam of low energy, neutral helium atoms is used as an imaging probe is a very new concept creating non-destructive and noninvasive surface investigation tool in science and industry. The He-beam is created by supersonic expansion from a high pressure reservoir through a nozzle. It is focused onto the sample by a mirror created from an electrostatically deformed single silicon wafer. The shape of the mirror is enforced by an electrode system controlled by a computer. The focusing mirror consists of a chemically-prepared silicon wafer placed between two aluminium discs and suspended above an electrode structure. The deflection of the mirror is controlled by an electric field between the wafer and the electrodes. The accuracy of the shape of the mirror is the most critical since it determines the resolution of the helium microscope. The required modeling of the mirror shape depends on initial quality of the wafer. Therefore it is planned to make various improvements to the mirror at both the macroscopic and atomic levels. This paper is focused on measurements of flatness and thickness of the wafer with high accuracy using specialized optics based techniques, so that the technological process of the wafers could be modified to obtain high quality material.

This paper describes an implementation of the communication layer based on remote procedure calling ONC RPC and presents the first prototype of hardware data protection module for control and data acquisition module being developed by the ELHEP Group for the DESY research center in Hamburg. This control and DAQ module is designed for the SIMCON module (SIMulator and CONtroller) aimed to steer the nine-cell super conducting niobium resonators built and produced for TESLA and X-FEL projects. Solutions described here will allow to establish safe connections from any place in the world and control physics experiments via Internet network.

The search for new physics at high energies is the motivation for the construction of the CMS (Compact Muon Solenoid) experiment at CERN, the European Organization for Nuclear Research in Geneva. It is designed to find answers to many of the open fundamental questions in physics through the study of proton-proton and heavy-ion collisions produced at the world's most powerful particle accelerator, the Large Hadron Collider. The CMS experiment, which is presently under construction, consists of a silicon inner tracker with an embedded precision vertex detector, a crystal electromagnetic calorimeter, a brass-scintillator hadron calorimeter, a muon system and detectors for the forward regions close to the beam axis of the accelerator. A superconducting coil generates a strong solenoidal magnetic field, which is required for the measurement of particle momenta. The trigger and data acquisition system selects events and stores them for the analysis. The search for the Higgs particle and Supersymmetry are amongst the principal research topics to be studied at the CMS experiment.

Several new experiments in particle physics are being prepared by large international consortia. During their lifetimes they will generate an unprecedented amount of petabytes (1015 B) of data, which have to be made accessible to large communities of researchers, distributed all over the world - this fact is one of the biggest challenges facing modern experimental physics. A possible solution is provided by the concept of a distributed computing Grid, made feasible by recent significant improvements in networking. Based on the results of several pilot Grid projects on both sides of the Atlantic, the LHC Computing Grid (LCG) project was launched in 2001, with the goal of creating a large prototype of a worldwide computing Grid for physics. Thousands of processors and a number of mass storage devices, belonging to different institutions of many countries, have been connected effectively into one computing system, controlled by the "virtual organizations" of experiments. This paper presents estimates of the computing requirements of future experiments, an overview of the Grid technology as well as progress on the construction of a computing Grid for particle physics and its use by the experiments.

In the frame of the CARE project, there is a Joint Research Activity (JRA2) called PHIN (PHoto-INjectors). The main objective of this JRA is to perform Research and Development on charge-production by interaction of a laser pulse with material within RF fields and improve or extend existing infrastructures. Another activity of PHIN is the coordination of the activities of various Institutes concerning photo-injectors. A brief review of the work of the eight European laboratories involved in PHIN will be presented. One of these R&D topics is the construction of a photo-injector for the CLIC Test Facility (CTF3). In this context the status of CTF3 and its main goals - the demonstration of the feasibility of the key issues of the CLIC two-beam acceleration scheme - will be presented.

Sources of an excess noise in avalanche photodiodes and photomultiplier tubes are considered in this paper. Special techniques for minimizing the noise contribution in detected signals are discussed. Typical applications of detectors in atomic spectroscopy and optical communication are used as illustration of the proposed tools for noise reduction.

This paper provides a review of various methods of optical control of microwave circuits by using p-i-n photodiodes. Theoretical and experimental studies have been carried out to investigate the effect of optical radiation on the capacitance and resistance of a p-i-n photodiode at low and high frequencies. Methods are discussed to increase the capacitance ratio and quality factor of a p-i-n photodiode operating as a varactor to implement optical control of microwave circuit.

We have investigated the radiation environment of the electron linear accelerators operating at DESY and explicitly identified the neutron and gamma radiation fields. Furthermore, we have studied the effects of the above radiations as well as neutrons from a dedicated irradiation device on various electronic components including CCD cameras and SRAM microchips. This report will highlight the activities currently undertaken by the radiation effect project group under the Accelerator Radiation Control (MSK) section of DESY.

Experimental techniques in physics, material science, biology and medicine want to gain profit from the advantages of the VLSI technology by using a new generation of electronic measurement systems based on parallel signal processing from the multielement sensors. In most cases key problems for building such system are multichannel mixed-mode Application Specific Integrated Circuits, which are capable to process small amplitude signals from multielement sensor. In this class of integrated circuits several important problems like power limitation, low level of noise, good matching performance and crosstalk effects must be solved simultaneously. This presentation shows two ASICs which, given the original solutions implemented and their universal properties, can be used in different applications and are significant milestones in experimental techniques. The first presented ASIC is the 64-channel charge amplifier with binary readout architecture for a low energy X-ray imaging techniques. This integrated circuit connected to silicon strip detector can be used in powder diffractometry and then it reduces the measurement time by two order of magnitude. The second presented ASIC is multichannel low noise readout for extracellular neural recording, which is able to cope with extracellular neuronal recording for the systems comprising several hundreds of electrodes. Important steps forward in this design are a novel solution for band-pass filters for low frequency range, which follow requirements for good matching, low power and small silicon area. This ASIC can be used to monitor the neural activity of such complicated system like retina or brain.

Fiber-Optic code division multiple access communication systems (FO-CDMA) have been given an intensifying interest in the last decade. This is due to several advantages may be offered by this technology, where it offers a promising solution for efficient truly asynchronous multiple access network as well as it has the ability to support variable bit rate and bursty traffic. FO-CDMA system permits an extra high optical signal processing speed compared to electronic signal processing, and there is no need to use wavelength sensitive components which are required in WDMA networks. FO-CDMA may be performed in time domain "t" or in wavelength domain "λ"(spectral amplitude encoding), this strategy is called one dimensional (1-D) optical coding. One of the most serious problems for CDMA is the multiple access interference (MAI), where it produces an asymptotic floor to the error probability, and limits the number of simultaneous users. Developing of FO-CDMA system to increase the number of users as well as to improve the system performance may be done through developing the system structure, choice of the appropriate detection scheme and the proper signature codes, developing the encoders and decoders hardware, use of adequate error correcting codes, incorporating optical amplifiers, use of multidimensional FO-CDMA techniques, and use of MAI cancellation and dispersion compensation techniques. This paper highlights the main directions of system development. The main technological challenges that have to be overcome before a wide spread of this technology have been also investigated. Finally, potential applications of this technology have been discussed.

The SC RF group at INFN Milano-LASA is involved both in the TESLA/TTF collaboration and in the research and design activity on superconducting cavities for proton accelerators. Among these activities, some are supported by the European community within the CARE project. In the framework of the JRASRF collaboration we are developing a coaxial blade tuner for ILC (International Linear Collider) cavities, integrated with piezoelectric actuators for the compensation of the Lorenz force detuning and microphonics perturbation. Another activity, regarding the improved component design on SC technology, based on the information retrieving about the status of art on ancillaries and experience of various laboratories involved in SCRF, has started in our laboratory. Finally, in the framework of the HIPPI collaboration, we are testing two low beta superconducting cavities, built for the Italian TRASCO project, to verify the possibility to use them for pulsed operation. All these activities will be described here, together with the main results and the future perspectives.

ALICE1 collaboration, which prepares one of the biggest physics experiments in the history, came into production phase of its detector. The experiment will start at LHC2 at CERN in 2007/2008. In the meantime about 1000 people from ~70 institutions are involved in this enterprise. ALICE detector consists of many sub-detectors, designed and manufactured in many laboratories and commercial firms, located mainly in Europe, but also in U.S., India, China and Korea. To assure appropriate working environment for such a specific task, strictly related to tests of particular components, measurements and assembly procedures Detector Construction Database system has been designed and implemented at CERN and at some labs involved in these activities. In this paper special attention is paid to this topic not only due to fact of innovative approach to the problem. Another reason is the group of young computer scientists (mainly students) from the Warsaw University of Technology, leaded by the author, has designed and developed the system for the whole experiment3. Another very interesting subject is the Data Acquisition System which has to fulfill very hard requirements concerning speed and high bandwidth. Required technical performance is achieved thanks to using PCI bus (usually in previous high energy physics experiments VME standard has been used) and optical links. Very general overview of the whole detector and physics goals of ALICE experiment will also be given.

Silicon technology enabled the miniaturization of computers and other electronic system for information storage, transmission and transformation allowing the development of the Knowledge Based Information Society. Despite the fact that silicon roadmap indicates possibilities for further improvement, already now the speed of electrons and the bandwidth of electronic circuits are not sufficient and photons are commonly utilized for signal transmission through optical fibers and purely photonic circuits promise further improvements. However materials used for these purposes II/V semiconductor compounds, glasses make integration of optoelectronic circuits with silicon complex an expensive. Therefore research on light generation, transformation and transmission in silicon is very active and recently, due to nanotechnology some spectacular results were achieved despite the fact that mechanisms of light generation are still discussed. Three topics will be discussed. Porous silicon was actively investigated due to its relatively efficient electroluminescence enabling its use in light sources. Its index of refraction, differs considerably from the index of silicon, and this allows its utilization for Bragg mirrors, wave guides and photonic crystals. The enormous surface enables several applications on medicine and biotechnology and in particular due to the effective chemo-modulation of its refracting index the design of optical chemosensors. An effective luminescence of doped and undoped nanocrystalline silicon opened another way for the construction of silicon light sources. Optical amplification was already discovered opening perspectives for the construction of nanosilicon lasers. Luminescences was observed at red, green and blue wavelengths. The used technology of silica and ion implantation are compatible with commonly used CMOS technology. Finally the recently developed and proved idea of optically pumped silicon Raman lasers, using nonlinearity and vibrations in the material to produce optical gain will be described.

The multimode optical fiber maximum operational range is defined by the fiber bandwidth (related to the intermodal dispersion) rather than by the fiber attenuation. The relation among the modal bandwidth of the fiber, the launching condition and mode coupling is fairly complicated. Presented is a theoretical and experimental study on the modal bandwidth of the multimode fiber. Theory is based on the numerical solution of coupled mode diffusion equation that allows for the bandwidth calculation of the MM optical fiber. The results are backed by measurements. In the Telecommunications Institute, Warsaw, such measurements may be performed up to ~600 MHz with a set up based on the frequency response measurement. The MM fibers are excited via a single mode patchcord with mechanically adjusted offset from the center. The patchcords with various MFDs can be used.

New algorithms have been introduced for extraction of defect centers parameters in semiconductors from experimental data obtained by photoinduced transient spectroscopy. The photocurrent decays are measured as function of time and temperature. The defect centers act as traps of charge carriers. Hence, each trap creates a specific fold on a correlation surface and on the Laplace surface and the ridges of folds correspond to the Arrhenius law. The quality of the data analysis depend mainly on the applied approximation methods. It is shown that the modern methods based on margin maximization and on regularization give excellent results. The analyzed are the following approximation methods: support vector machine, sparse least square support vector machine. The important advantages of these models are as follows: good accuracy of approximation, analytic representation of considered surfaces, low complexity and finally excellent generalization. Hence, they enable to obtain more exact values of investigated defects and better discrimination of observed defects

In this paper a concept of a non-contact method of temperature and humidity measurements based on the thermooptic and higroscopic effects of A₂MX₄ crystals is presented. Temperature and humidity influences on optical properties of some crystals were investigated. Possibilities of application of the A₂MX₄ crystals as a temperature and humidity sensors were discussed.

Introduction of computer polishing machines has improved the flatness correction obtained on large optical components in different fields of activity (Astronomy, High Power Lasers, Space Activity, X-ray Mirrors for Synchrotron). It is now possible to produce off-axis aspheric mirrors with incidence angle greater than 20 degrees or aspheres with aperture number greater than F/1. To produce optics for Fusion by laser or large telescopes projects special machines or facilities have to be designed and installed. We will show the kind of studies, which are done in order to be able to produce these components as serial products and show some statistical results of flatness errors achieved on a production of 400 by 400 mm² flat windows.

The paper presents the concept of passive detection of moving targets based on thermal radiation in microwave region. Up to now the passive detection of moving targets, especially airplanes and ground vehicles is performed using infrared sensor. The microwave radiometric methods are now widely used in many other fields of applications, such as radio astronomy, remote sensing, medicine, pollution control, mine detection and other. All these methods are based on measurement of power of thermal noise radiated by hot surface. The usage of power-only information is usually not sufficient to discriminate between moving and stationary target. To sense the target movement different phenomena can be applied. The most fundamental one is Doppler shift of the spectrum of radiating thermal noise. To perform this task complex envelope of received signal must be recorded and Doppler processing must be applied. The Doppler and time correlations are widely used in radio astronomy, for sensing the weather and for high-resolution image creation, but up to now was not exploited for moving target indication, so important in ATC applications. The fundamental problem - distinction between stationary and moving targets is performed by calculating range-Doppler correlation between thermal signals obtained from different localization in multi-static radiometric antenna constellation. Further more, using correlation principles, it is possible to obtain high resolution images of the detected objects.

In the biomedical applications it is often necessary to collect measurement data from different devices. It is relatively easy, if the devices are equipped with a MIB or Ethernet interface, however often they feature only the asynchronous serial link, and sometimes the measured values are available only as the analog signals. The system presented in the paper is a low cost alternative to commercially available data acquisition systems. The hardware and software architecture of the system is fully open, so it is possible to customize it for particular needs. The presented system offers various possibilities to connect it to the computer based data processing unit - e.g. using the USB or Ethernet ports. Both interfaces allow also to use many such systems in parallel to increase amount of serial and analog inputs. The open source software used in the system makes possible to process the acquired data with standard tools like MATLAB, Scilab or Octave, or with a dedicated, user supplied application.

The paper describes possible configuration of hardware and a bunch of Matlab functions of controller and simulator of the resonant superconducting, narrowband niobium cavity, originally considered for the TTF and TESLA in DESY, Hamburg (now predicted for the VUV and X-Ray FEL). The configuration of the hardware can be done in different ways to achieve the most adequate setup to the requirements. There is described set of basic Matlab functions for advanced users and developers of control algorithms. The functions allow to configure basic features and functionality of the SIMCON device.

Properties of whispering gallery modes in microresonators of different types proposed lately may be analyzed with the help of introducing equivalent spheroid. We describe and compare two methods of approximate calculation of scalar field equation in such spheroid.

Low cost, high bandwidth, narrowband and multifunctionality are main targets for new optical devices development. Planar optics is probably the best solution for future telecom long distance and access transmission networks but also for metrology sensing devices. Many different materials can be used for this purpose like PECVD silica, multicomponent glasses or even polymers. Bragg grating inscription in such material is another advantage to achieve narrowband spectral characteristic of device, which is essential in modern systems. The main purpose of presented work was the development in technology and measurement techniques of channels formed on the surface of the glass. Planar couplers and structures that are more complicated can also be made in the same technology in the future. Special multicomponent glasses SiO₂-GeO₂-B₂O₃-Na₂O-SnO₂ with up to 6 %mol of Sn were synthetized and thin rectangular polished plates were prepared. The UV 244 nm 100 mW Coherent argon ion frequency doubled laser was used in our experiments. Surface relief structures similar to the compaction-densification/expansion model of photosensitivity were developed on the glass surface. The optical microscope and alpha-step profiler were used for preliminary tests of photoinduced structures on the glass surface. The ability of the writing possibility in function of Sn content and different laser power levels were analyzed.

A major concern in the petrochemical industry is both safety and efficiency of process heaters operation. As the tubes temperature and the symmetry of heating belong to the critical components, infrared imaging and measuring methods have been used worldwide for many years. Monitoring these high temperature objects has frequently been relying on highly subjective analyses, particularly due to fluctuations of flame and heating medium and/or sometimes inaccurate or not well-fit thermocouple data. Recent developments in infrared camera technology and data processing possibilities have brought significant progress for high resolution spatial and temporal analysis of infrared radiation distributions. This paper presents an innovative method which deals with the flickering and spectrally selective features of the heating mediums, analysed basing on capturing and elaboration of long sequence of images instead of the snapshot method. Thereupon, digital image processing algorithms enable automatic search of a few chosen statistic values for every pixel of the every frame, with the aim to form substitute images, which consist only from pixels of min., max, or mean values and their standard deviation distributions. By applying this new methodology, it is possible to separate extremes of fluctuating signals and, in result, to obtain deeper and more reliable knowledge about temperature distributions or about heating phenomena inside process furnaces. These data can be utilised to significantly increase heater throughput while helping to ensure safe operation of the heater. Many other applications could take advantage of presented idea, algorithm and tools.

The paper presents an attempt to unify the construction of two state optical fibre loop sensor and possibility of adapting it to the various traditional constructions and casings of industrial sensors. This enables module structure of sensors based on construction of industrial application (master) and mensurative optical fibre loop (slave). Mensurative properties are determined by traditional (mainly mechanical) measuring system ex. temperature, displacement, and optical properties are determined by characteristics of auxiliary optical system (standardised and unified). Such attitude to a subject is illustrated in this paper by the examples of threshold displacement sensor, temperature, voltage and current.

In this paper we present an initial result of a novel architecture of an all-optical buffer by re-circulating packets dynamically using Semiconductor Optical Amplifier (SOA) and Fiber Bragg Grating (FBG). We then compare this architecture with typical re-circulating buffer with respect to output power and the eye diagram. We start our work by investigating the performance of wavelength routed optical network using an Object Oriented Programming methodology (OOP). In particular, we examine wavelength routed switching matrix architecture employing Arrayed Waveguide Grating (AWG), multiplexer (MUX) and demultiplexer (DEMUX) and SOA. Parameters of interest are throughput and packet loss of different number of optical buffer used with different offered load.

An Optical coherence tomography system (OCT system) was developed to measure physiological response inside plant. This system has a unique optical scanner of wide scanning range of 40mm to adapt the OCT measurement to irregular features and many breeds of plant samples. To use in the outdoor field, which plants volunteers, the system should be compact, stable, and have high repetition frequency of measurement. We designed the OCT system with the original optical scanner and optical fiber optics for the purpose. The transmittance and reflectance characteristics of the plant leaves were examined to check the water absorption. The SLD-light of the wavelength of 830nm was selected for the measurement light source. Various kinds of plant samples were measured to evaluate the system performance and its adaptive flexibility. Cell structure of plant surface, its change due to the water content, and growth monitoring of plant tissue were measured. The concrete application was also demonstrated.

This paper describes the design of the Link Box Control System for the RPC Detector (RLBCS), emphasizing the features needed to assure reliable operation in the irradiated environment of the RPC detector and its neighbourhood. The development process required to balance different factors - radiation hardness, reliability, flexibility, firmware upgrade possibilities, diagnostic features. The final design presented in the paper is a result of compromise between the above requirements.

There are several technologies for cheap mass fabrication of microelements. When we need elements of high structural depth, one of the most important technologies is the LIGA process. Since this method is time- and cost-consuming, there are a few alternative methods to be used instead of the LIGA. One of them is the use of the ion track lithography, especially deep proton lithography. So far, all the deep lithography setups have operated in vacuum. Accelerated protons were focused or formed by a mask to light a target placed in vacuum. Such an approach limited the size of the target and lengthened the time needed to place a new the target in the setup. It also needed a relatively small steering setup, adapted to operate in vacuum. That is why a novel proton lithography setup operating in the air has been proposed. The setup, whose size is no longer limited, allows for a quick access to the target. However, the parameters of the proton beam moving from vacuum into the air change, which affects the way protons interact with the target. This enforces adding several new elements to the classical proton lithography setup. In spite of that, such a setup is cheaper and easier to use than the classical one, but it allows for obtaining microelements of similar quality.

We consider design of hardware realizations of optoelectronic logical elements of two-valued logic with current inputs and current outputs on the basis of CMOS current mirrors and circuits which realize the limited difference functions. We show advantages of such elements consisting in encoding of Boolean variables by the photocurrent levels, that allows easily to provide optical inputs (by photodetectors) and optical outputs (by light-emitting devices). The conception of construction of the family of the offered optoelectronic photocurrent logical elements (OPLE) consists in the use of a few current mirrors realized on 1.5μm technology CMOS transistors. Presence of four - ten transistors, one - two photodetectors makes the offered circuits quite compact and allows their integration in 1D and 2D arrays. In the presentation we consider the whole family of the offered circuits, show the simulation results and possible prospects of application of the circuits in particular for time-pulse coding for multivalued, continuous, neuro-fuzzy and matrix logics. The simulation results of the NOT, AND, OR, OR-NOT current logical elements on the 1.5um technology CMOS transistors showed that the level of logical unit can change from 1 uA to 10 uA for low-power consumption variants and from 10uA to 100uA for high-speed variants. Signals delays, values of fronts and cutoffs at operation with impulse logical signals with 1uA logical unit are not exceed 70-140ns and at operation with impulse logical signals with 100uA logical unit are no more than 4-6ns and the consumption power is 200-400uW.

"Pi of the Sky" is a detector designed for search for optical flashes of the cosmic origin in the sky. Its primary goal is to look for optical afterglows associated with the gamma ray bursts (GRB), but it is capable to detect also other optical transients of extragalactic origin. The apparatus consists of two arrays of 16 cameras each, which allow for simultaneous observation of the whole sky. Due to on-line data analysis in the real time, it has self-triggering capability and can react to external triggers with negative time delay. The prototype with two cameras has been installed at Las Campanas (Chile) and is operational from July 2004. General idea of experiment, the apparatus and its performance will be presented. Physical results will be reviewed and perspectives for the future will be outlined.

Modern research trends require observation of fainter and fainter astronomical objects on large areas of the sky. This implies usage of systems with high temporal and optical resolution with computer based data acquisition and processing. Therefore Charge Coupled Devices became so popular. They offer quick picture conversion with much better quality than film based technologies. There are two main trends in astronomical observations. First one is construction of large telescopes with sensitive picture sensors. They allow further exploration of the Universe. An example is the KECK telescope in Hawaii. The other trend is presented by systems that perform observation of large areas of the sky with high resolution in time. They are used to investigate objects, which rapidly change their position or intensity. They are often quite bright, thus the sensitivity of such measurement systems is not so critical. Because of huge amount of data from detector, the analysis must be performed on-line. This way, there is a large reduction of data that are archived and processed later. The example of project that realizes the concept of variable sky objects observation is "Pi of The Sky". The main field of interest is detection of optical flashes that accompany star's explosions. The conditions that are present during such an events are similar to ones that had place in the young Universe. That's why this research is interesting also for particle physics. This work is theoretical and practical study of the CCD based picture acquisition system. This system was optimized for "Pi of The Sky" project. But it can be adapted to another professional astronomical researches. The work includes issue of picture conversion, signal acquisition, data transfer and mechanical construction of the device.

Beamsplitter is a crucial element of the Fourier spectrometer. In conventional form it is composed of two identical wedge plates reducing ghost reflections influence. Simultaneously, it can introduce the most significant spectrum errors in the reason of improper quality or misalignment. The influence of geometrical parameters of both wedge plates on measured spectrum is presented. The paper contains numerical analyses for assumed and real object spectrum. Additionally the dependence between incident wave shape and quality of reconstructed spectrum is considered.

Sensing properties of fiber Bragg grating (FBG) strain sensors produced in photosensitive optical fibers was the main task of the presentation. Several Bragg gratings were made by the scanning phase mask method. The standard telecom matched-clad fibers were used in the experiment but it was necessary to hydrogenate them before the UV illumination. We have hydrogenated our fibers for up to 30 days under the pressure of 130 bar. The double frequency 244 nm 100 mW Coherent argon ion laser was used. Bragg gratings spectral characteristics were measured, filter central wavelength and FWHM determined. Grating were stretched and their strain sensitivity determined. FBG was also attached to the surface of elastic bar. It was bended in the grating squeeze and stretch configurations. The linear response of the Bragg wavelength shift was observed in all experiments. Total wavelength shift of 10 nm was easily measured by our monochromator system in the range ±4355 με. The experimental results were compared to theoretical data obtained from simple model bar equations. We have found good agreement between theory and experiment. FWHM values remained nearly unchanged. We believe the model simplicity as the source of small discrepancies.

A scanning helium atom microscope, is a very promising tool in surface science. In this technique a focused beam of low energy, neutral helium atoms is used as an imaging probe. The method is suitable to be applied to surface investigation in science and industry. The He-beam is created by supersonic expansion from a high pressure reservoir through a nozzle. It is focused onto the sample by a mirror created from an electrostatically deformed single silicon wafer. The shape of the mirror is obtained by an electrode system controlled by a computer. The focusing mirror consists of a chemically-prepared silicon wafer placed between two aluminium discs and suspended above an electrode structure. The surface quality of the mirror is the most crucial because it limits resolution of the helium microscope. Therefore it is planned to make various improvements to the mirror at both the macroscopic and atomic levels. The centre of gravity of the paper is in measurements of the surface quality of the wafer using scattered light based technique and AFM, so that the technological process of the wafers could be modified to obtain improved surface. The roughness was studied for the (111) oriented mechanically-chemically polished surfaces of silicon wafers with different miscut. The wafers with miscut of 0°, ± 0.25^o and ± 0.5^o toward (11bar2) direction were used for experiments. The miscut was determined with the accuracy of ±1'.

The paper presents results of comparative analysis of some basic properties of multicavity photoacoustic Helmholtz cells. The analysed cells were three-cavity Helmholtz resonators formed from a standard dual-cavity photoacoustic Helmholtz cell with an additional cavity connected by means of a capillary with the sample cavity of the cell at the other end. Influence of change of the volume of the additional cavity as well as diameter and length of the connecting duct on the microphone signal vs. frequency was studied. Analysis was based on computer simulations in which a modified transmission line model was used. The model was improved by introducing of additional damping factors which values were extracted from measurements of number of practically implemented dual-cavity photoacoustic Helmholtz cells. The analysis showed that additional cavity makes it possible to improve shape of the frequency response of the cell. In particular it is possible to extend range of frequencies in which resonance properties of the cell can be used for the purpose of photoacoustic signal amplification. It should be noticed that choice of the cell dimensions must be careful, as some combinations decrease resonance properties of the cell.

The luminous intensity unit and traceability in derived units of illuminance and luminance were realized using new detector-based approach at the National Metrology Institute of Turkey. Services in photometry were enlarged to perform high-level illuminance and luminance meter calibrations, namely at levels up to 5000 lx and 5000 cd/m² by using the working standard photometer heads, precise apertures and integrating spheres on the 6 m long photometric bench. Working standart photometer heads which consist of a single silicon photodiode, V(λ)-corrected filter, precision aperture and a cosine corrected diffuser were calibrated for luminous responsivity in A/lx. For precision in the measurements, positions of illuminance meters and photometer heads are compared by using step motor controlled translation stages. The measurements are carried out at the color temperature of 2856 K and in the conditions where the inverse square law is applicable. The same photometer heads are used to measure luminance unit. The purpose of the work is to present established photometric systems and describe capability which is being applied at UME for the realization of calibrations of illuminance-meters and luminance-meters.

The proposed numerical model of 2D W/T optical CDMA system with optical hard-limiters is presented in this paper. The decoder input and output signal, average signal to interference difference and bit error probability as a function of active user number and weight of codeword for the different topologies of the decoder have been simulated. The influence of non-ideal properties of the used optical hard-limiters and different topologies of the decoder upon average signal to interference difference and bit error probability in system are studied.

A planar phase Doppler system and a photon correlation LDA system was simulated regarding to particle size measurement below 150nm size range. Light scattering on Gaussian beams was simulated by Lorenz-Mie theory (LMT) and superimposed on the detectors' surface. The planar PDA system was found unable to size measurement in this range. Particle size measurement from photon correlated LDA signal is discussed particularly. Adaptability of method developed for visibility measuring was investigated. We established that the total number of photon counts from passing particles is a good estimator of particle size in this size range, because scattered intensity does not oscillate with the size changes. The two particle sizing methods were compared. The photon counting method was found simpler and more sensitive. Dependence on particle trajectory is investigated and found it is comparable for the two methods.

Analysis of important metrological problems of Raman investigation of solid state thin films is given in this paper. Raman studies of such films can be carried out as ex-situ measurements conducted for a sample outside the reaction vessel after manufacturing process or as in-situ monitoring of film deposition. First approach gives more possibilities of structure investigation while the second one can be used for optimisation of the manufacturing process parameters. One of the most important problems in the investigation of thin films is low level of the useful Raman signal, which is result of a small path length in the sample and, in some cases, optical properties of investigated materials. Moreover, for some applications, especially in-situ monitoring, it is difficult to excite the proper part of investigated structure. Consequently, sophisticated optical setups must be applied to ensure sufficient sensitivity of the measurement system. Raman systems able to use in investigation of thin solid films and monitoring of their deposition processes are presented. Results of Raman investigation of selected structures, starting from monocrystals through polycrystalline thin films to the amorphous ones are presented.

In this paper we present the fabrication of optical mode field adaptors for fiber optical communications devices in combination with a new method for spot size measurement for single mode optical components. At the end of standard single mode fibers we have manufactured reproducible mode field transformers with diameters from 5 μm to 90 μm. Additionally, we present a new planar optical field characterization method. BPM simulations are performed to predict the spot sizes at different fiber end diameters. Based on the measurement of a singlemode fiber in accordance with ITU Recommendation G.652 the efficiency is demonstrated and discussed.

We are reporting on research and development of a water pollution remote sensing technique, based on laser induced fluorescence of organic pollutants floating on the water level or dissolved in water. We are relying on a diode pumped Nd:YAG microlaser, providing 1 microjoule 600 ps long pulses at 532 nanometers wavelength with repetition rate of 10 kHz within a compact, small and low power package. The fluorescence signal is detected by a silicon photon counting detector. A compact time to digital converter with 20 picoseconds timing resolution and a personal computer interface has been constructed for the device. The small receiving optics apertures together with advanced time filtering of the detected signal permits to operate in an outdoor environment in a daylight background conditions with acceptable signal to noise ratio. The indoor tests of the device indicate its capability of detection of sub-micrometer oil films on the water level even at high noon. The capability of detection of dissolved organic substances has been demonstrated as well.

The method of transmission of information about high spatial frequencies of optical object on low frequencies is developed. The method is based on a statistically optimal solution of the Fredholm's integral equation of the first kind, which describes the general process of formation of signals and images. The given solution allows to use transmission of several images of the same object, which differ by conditions of formation (the kind of illumination, modulation, etc.), through limited channel capacity of system. The method is mathematically justified and suitable for processing linearly generated images registered by optoelectronics system on the basis of a focal-plane array. Here we introduce the quantitative information-theoretical performance evaluation of optoelectronics system as the minimum probability estimation of restoration error to exceed of specified value. Its values depend on the geometrical shape and spectral photosensitivity of pixels, fill factor of focal-plane array and point spread function of system. For several optoelectronics systems of image registration of the same object this performance depends on the point spread function of each system. Given information performance allows to optimize the theoretical determination of requirements of images formation for transmission. Numerous simulations and physical experiments that confirm the possibility of transmission of information about high spatial frequencies are carried out. The experiments show that our method makes possible the super-resolution restoration of images, which are heavy blurred by light scattering and the diffraction limits of optical system.

The possibilities of development of logical and pseudo-logical optical fibre networks for monitoring and control of equipment and industrial sites are presented. Such networks composed of simple binary attenuation and optical fibre communication lines may also be used as fast and reliable systems developing a final command signal - logical and/or pseudo-logical, depending or the architecture of network and the type of located sensors. They realise the process similar to standard electronic logical sets but use the optical signal directly on the monitored or controlled device. The analysis of serial and parallel networks was carried out in the "dark" mode detection. The examples of networks in power industry were presented where technical and economical merits of logical and pseudo-logical monitoring and controlling networks are clearly visible.

The MOSIX Cluster project is an attempt to build a full functional cluster machine which consists of many different PC stations. The idea is to create a general purpose structure, which will be used for many different projects and calculations. Our machine is a heterogeneous system (consists of nodes with many different architectures), which makes it very interesting during the testing phase. It is tested with OBCA tasks, which need quick connection between nodes and often make such operations like reading and writing to disk. Many comparisons of efficiency are made during testing and calculations.

Today, the fast optical data transmission is one of the fundamentals of modern distributed control systems. The fibers are widely use as multi-gigabit data stream medium. For a short range transmission, the multimode fibers are in common use. The data rate for this kind of transmission exceeds 10 Gbps for 10 Gigabit Ethernet and 10G Fibre Channel protocols. The Field Programmable Gate Arrays are one of the opportunities of managing the optical transmission. This article is concerning a synchronous optical transmission system via a multimode fiber. The transmission is controlled by the FPGA of two manufacturers: Xilinx and Altera. This paper contains the newest technology overview and market device parameters. It also describes a board for the optical transmission, technical details of the transmission and optical transmission results.

Studies of application of Raman spectroscopy in measurement of important parameters of rheometric process, including profile of oil film thickness and composition of oil/paste system, were carried out. The films of silicone oil AK10⁶ (Wacker) extracted from ceramic paste AlOOH were subjects of investigations presented in this paper. Boundary between oil film and extruded paste is not regular and ambiguous during the extrusion process of ceramic paste in capillary rheometer. Moreover, the pastes are scattering materials, what makes determination of the film thickness by conventional optical methods difficult. Preliminary Raman measurements were made separately for oil and paste samples in range extending from 50 to 3500 cm^-1. Determination of main Raman bands assigned to oil, ceramics and glass showed that Raman spectroscopy enables discernment of these materials. During the next step, studies were conducted for a model sample of the oil spread on the paste, using Raman microscope. This device was equipped with long-working-distance objective which should enable remote measurements through a borosilicate, view-port-window in the wall of capillary rheometry die. Two methods of Raman determination of the thickness were compared. Results of analysis and experimental works suggest that one of them can be applied for in-situ monitoring of the extrusion process.

The work presents an 8-channel control system for a superconducting cavity accelerating module ACC1 of the VUVFEL machine. The integration was described of a monitoring layer with the DSP control layer realized in the programmable Xilinx VirtexII V4000 circuit. The implementation was realized in the VHDL. The hardware multiplication blocks were used which are embedded in the FPGA circuit. The final implementation of the device was presented. The device works in the real time, according to the nominal demands of the VUV-FEL machine. The paper describes the monitoring layer. There were shortly characterized particular functional blocks of the layers implemented in the FPGA circuit. There was presented a computer process of system supervision which uses the monitoring layer. Some chosen examples were presented to illustrate the real-time monitoring processes during the nominal work conditions of the VUV-FEL machine.

The method of an effective control of superconductor optoelectronic devices by commonly used current and optical radiation pulses is proposed. Numerical modeling of the resistive responses has been conducted for thin film structures based on high-T_c superconductor (HTS) YBa₂Cu₃O_7-x. As a results of calculations, the control characteristics of HTS-switches in the form of switching time dependences on the control mode were obtained. On the basis of this, threshold characteristics of switching and optimal control characteristics of investigated elements were obtained. It is shown that applying of together acting current and laser radiation allows to effective switching of HTS-elements with significantly decreased pulses' amplitudes. Reduction of current amplitude lets to avoid thermal instability and reduction of needed radiation flux allows to apply semiconductor lasers.

The paper presents analyses of a testing system of extreme ultraviolet detectors. The testing procedure concerns determination of a quantum efficiency of photodiode detectors. The testing method is based on a comparison of the detected signals from the model detector and the tested one The system consists of a gas-puff laser plasma source, a metrology chamber with an optical system, and a model energy detector. Theoretical and experimental investigations, including optimisation of efficiency and stability of the radiation source, calculation of a charge measurement accuracy of the model detector, determination of mirrors reflectivity and its angle dependence are discussed.

Based on infrared thermography, a non-destructive testing and evaluation (NDT&E) procedure is proposed for defects assessment on radiant heaters. Under a short electrical excitation, an infrared camera captures the cooling process of the heaters. Breaking the thermographic images down not only makes easiest the location of defects but it also allows their classification. Several kinds of defects have been taken into account: lack of supporting brackets; defects originated by a deficiency in the heating material; those from an excess of heating material; and those parts of the heating elements which are in wrong contact (non-contact or semi-buried) with the substrate. Each kind of analyzed defect has a different thermal history after the electrical excitation because of its nature. By means of computer vision techniques, the defects can be spatially located. The "chain code" was employed to follow the pattern of the heating element and so concentrate the analysis in points belonging to the pattern. A good agreement with analysis made under human's criteria is achieved. However, using infrared cameras and processing the data with computer vision algorithms allows controlling in-site the quality of the product without any subjectivity. So, the heaters manufacturing industry could come along with the implementation of this automatic detection procedure. Experimental results that validate the proposed method will be presented and discussed in this paper.

The spectroscopic analysis of the light emitted by thermal plasmas has found many applications, from chemical analysis to monitoring and control of industrial processes. Particularly, it has been demonstrated that the analysis of the thermal plasma generated during arc or laser welding can supply information about the process and, thus, about the quality of the weld. In some critical applications (e.g. the aerospace sector), an early, real-time detection of defects in the weld seam (oxidation, porosity, lack of penetration, ...) is highly desirable as it can reduce expensive non-destructive testing (NDT). Among others techniques, full spectroscopic analysis of the plasma emission is known to offer rich information about the process itself, but it is also very demanding in terms of real-time implementations. In this paper, we proposed a technique for the analysis of the plasma emission spectrum that is able to detect, in real-time, changes in the process parameters that could lead to the formation of defects in the weld seam. It is based on the estimation of the electronic temperature of the plasma through the analysis of the emission peaks from multiple atomic species. Unlike traditional techniques, which usually involve peak fitting to Voigt functions using the Levenberg-Marquardt recursive method, we employ the LPO (Linear Phase Operator) sub-pixel algorithm to accurately estimate the central wavelength of the peaks (allowing an automatic identification of each atomic species) and cubic-spline interpolation of the noisy data to obtain the intensity and width of the peaks. Experimental tests on TIG-welding using fiber-optic capture of light and a low-cost CCD-based spectrometer, show that some typical defects can be easily detected and identified with this technique, whose typical processing time for multiple peak analysis is less than 20msec. running in a conventional PC.

The paper presents a detection method of laser radiation using photoacoustic converter. Mathematical-physical model of the converter and its numerical analysis is described. Influence of selected design factors and operation conditions on a level of a voltage signal produced at a converter output was analysed. The results of theoretical investigations have been confirmed by the experimental ones.

In the work there were presented research referred to Gaussian refractive index profile which appears in thermal joint area of splicing different types of single mode fibers with circular symmetry and weakly guiding i.e. different types of telecommunication fibers. There were presented results of measurements of coupling loss appeared in thermal joint area of splicing different types of telecommunication fibers and their interpretation that takes into consideration diffusion of dopant from core and description of fundamental mode field and refractive index by Gaussian function.

This work presents a mathematical analysis of the propagation of luminous flux in the curvatures of optical fibres based on the equation of a torus. The influence of the fibre curvature on the value of the luminous flux transmission coefficient was determined. On the basis of this analysis a computer program has been designed enabling to determine the transmission coefficient of the optical fibre. Comparing the data obtained from the computer simulation with the data from experimental verification it may be stated that the program determines the loss factor resulting from the fibre curvature quite well. The error between the actual measurements and the results obtained from the computer simulation ranged from 1,8% to 12,2%. The program may be a useful tool for designing lighting optical fibres used in various types of optical fibre systems.

Analysis of luminous flux transfer trough a conical ring-core light guide is presented. This kind of optical guide is used by the authors to build a measuring device which enables to determine the distribution of luminance in the visual space. The angles of acceptance can be selected at random, thus the solid angle, in which the distribution of luminance is analysed, can practically be divided into a chosen number of zones. In the section perpendicular to its axis, the light guide can have an elliptical shape with different angles of acceptance. In such a way it is possible to adjust the division of the space into zones better and create a parallel with two-eye sight (smaller zones in the vertical section, bigger in the horizontal plane). The conical output surface with great vertical angle considerably improves the process of the transfer of the luminous flux trough a conical ring-core light guide. Replacing a flat outlet surface of the light guide by a conical one makes the transferred luminous flux to some extent more uniform.

We have discussed transmission of the luminous flux through the optical fibre with a flat input surface and a spherical output surface. In this discussion we have considered the basic losses of the luminous flux.: Fresnel reflections, absorption of the core material on the optical path, and imperfections of the internal reflection. The curves of luminous intensity of the solids of light distribution in the optical fibre mating with a halogen bulb have been given as well.

The field and light induced emission of electrons from ITO film into vacuum has been investigated. Under influence of applied voltage, within the interval from -2 kV to 0V, electron emission into vacuum occured. With increasing voltage and under illumination the electron emission grows monotonically. At low voltage (≤ |-500V|) the increase is linear. At higher voltage this dependence is exponential. Upon the internal field and illumination influence, the emission is about twice as much as without illumination. This may be evidence that the electric field initiates electron collisions, which proceed according to the impact ionization mechanism. The emission intensity-electron energy distribution was found to be close to the Gauss probability function. We have also found the Poisson distribution can be used instead of the Gauss one.

Some aspects of calibration of photoacoustic instruments are discussed in this paper. In most reports concerning photoacoustic experiments, measurement results are given in arbitrary units. Traditional calibration methods of photoacoustic cells are based on measurements of known concentration of a reference substance. However, from the point of view of such calibration methods, instruments of identical sensitivity but with different internal volumes will produce different responses if the same amount of investigated specimen is used in both cases. This may create problems in measurements when the amount of investigated specimen is limited. The paper presents a method that can be used to improve calibration of photoacoustic cells and associated electronics. The method uses acoustical pressure produced by a piezoelectric disc mounted in the cell and driven from an external oscillator circuit, so that it is possible to compare the amount of sound energy with the amplitude of the electric signal at the sound detector output. In such a way it is possible to evaluate energetic efficiency of the cell and the associated electronic circuit, to determine overall sensitivity of the setup, its signal to noise ratio, etc.

A new version of the SIMCON system is presented in this paper. The SIMCON stands for the microwave, resonant, superconductive accelerator cavity simulator and controller (embracing the hardware and software layers). The current version of the SIMCON is 3.1. which is a considerable step forward from the previous 8-channel version 3.0. which was released at the beginning of 2005 and was made operable in April. Many important upgrades were implemented in SIMCON 3.1. It is a stand-alone VME board (whereas SIMCON 3.0 was modular) based on the Virtex II Pro 30 chip with two embedded Power PCs and DSP blocks. It has Ethernet and multiple gigabit optical I/Os. The Simcon 3.1 board provides 10 ADC channels. The architecture idea and block diagrams of the PCB for SIMCON 3.1. are presented. Some of the applied novel technical solutions, Protel"R" views and schemes are shown. A number of initial conclusions were drawn from a few month experience with the development of this new board. The tables of predicted system parameters are quoted.

This paper presents research on adaptive control (AC) of combustion process in industry. Results were obtained from research conducted in laboratory combustion chamber with usage of Fibre Optical Measurement System (FOMS) with electronic block. Simulation proved that implementing AC and FOMS to burning process improves flue gasses parameters - direct measure of power boiler ecological and economical quality of work.

An application of a CCD matrix in photometric instrument generates a new metrological potential. Proper algorithms of calibration, spatial data recovering and processing provide obtaining the proper information e.g. about the luminance distribution in the human field of view or the front of the fibre. Some aspects of data processing in the luminance distribution measurements (for various applications) will be discussed.

The background luminance informs of the vision adaptation level of the person staying in examined lighting conditions. The method of estimation of the background luminance will be presented. It utilizes the CCD matrix that carries the information about the luminance distribution in the human field of view. Some values that are useful in glare estimation, including background luminance, are the result of the numerical analysis of this distribution.

We have used reflectance spectroscopy for the in-situ, non-invasive monitoring of a thin oil film thickness during extrusion process of ceramic paste in capillary rheometer. Investigated pastes are disperse solid liquid systems prepared from the silicone oil AK106 (Wacker) and ceramic powder AlOOH. The thin oil film, extracted from the extruded paste, appears on walls of the rheometer die. A borosilicate view-port-glass provides optical access to the thin film inside the die. Reflectance spectroscopy enables the thin film thickness measurements by wideband spectral analysis of light back reflected from the sample. This spectrum includes extremes, which results from interference between beams reflected from glass-oil boundary and oil-paste boundary. Position and intensity of this extremes were determined by thickness of the thin film as well as refractive indices of the oil and the paste. Optoelectronic system dedicated for process monitoring by means of reflectance spectroscopy had been designed and built. The system comprises tungsten halogen lamp and fiber optic spectrometer. Optical signals are transmitted through bifurcated fibers, focusing optics and the view-port-window. Spectroscopic monitoring was carried out in VIS-NIR range from 400 to 900 nm as a function of extrusion velocity (0.01-5mm/s) and paste particle granulation (5-20 μm). Computer calculation, performed using dedicated software, enables fast determination of thickness even for reflectance spectra interfered by high noise level. Fast development of ceramic components technology requires detailed description of complex rheometric processes. Monitoring of the most important process parameter - oil layer thickness - enables pre-determination of rheometric factors required for proper paste extrusion and accurate shape filling.

The permanent optimization of combustion equipment could provide very important benefits in terms of efficiency, reliability and reduced pollution. However, current capabilities for monitoring and control of industrial flames are very limited; the lack of reliable diagnostic techniques is, most probably, the main obstacle to achieve those goals. Novel instrumentation systems based on the processing of the radiation emitted by the flames could help greatly to fill this gap, as radiation signals are known to contain very rich information about flame properties Optical sensors offer the benefit of being selective, rapid and able to gather data from extremely hostile environments. Passive optical sensors offer the further advantages of simplicity and low cost. With the rapidly growing capability of sensor hardware, there is an increased interest and need to develop data interpretation strategies that will allow optical flame emission data to be converted into meaningful combustor state information. The present work describes new results achieved on the use of optical sensors for the development of advanced monitoring systems of lean-premixed flames representative of gas turbine combustors. Different complementary signals have been analyzed: broad band emission using a Si photodiode, a narrow band around 310 nm measured with a photomultiplier and measurement of UV+VIS emission spectra. The signals have been processed using both conventional and advanced methods. The results obtained demonstrate that optical sensors can yield useful, instantaneous information on the actual flame properties, not available with the sensors currently used in practical combustion systems.

This paper presents the results of spectroscopic investigations on a synthetic dye solution with high fluorescence quantum yield and mixtures of this solution with colloidal silver particles. Basing on the results obtained the influence of the metal nano-particles presence on the changes of intensity and fluorescence quantum yield of the dye was determined. The purpose of the investigation was to determine the usefulness of fluoresceine in the structure of sensors and indicators of metal presence in the environment. The measurements were made for fluoresceine water solutions and its mixtures in the ranges of concentrations from 10^-6 M to 10^-3 M. A significant growth of the fluorescence quantum yield in the presence of colloidal particles was only observed in the range of concentrations from 2•10^-4 M to 8•10^-4 M.

In this paper the application of the Inverse Least Squares algorithm (ILS) to the detection of methane using its behaviour in the near-infrared band is presented. In order to test the effectiveness of this method, different methane concentrations were measured. Wavelength Modulation Spectroscopy (WMS) was employed to obtain the first and second harmonics of the modulation signal. The use of both harmonics in spectroscopy eliminates the dependence of the measured absorbance on parameters such as: fiber misalignments, optical power fluctuations, etc. This property greatly increases the accuracy of the concentration readings. The benefits of analysing multiple lines in gas detection are discussed together with the capabilities of the ILS algorithm. The ILS algorithm is based on the Beer-Lambert law. This law is extended to include multiple wavelengths and rearranged in such a way that the concentration of the chemical species depends on the measured absorbances. In order to apply the previous algorithm, three absorption lines centered at 1665.961 nm, 1666.201 nm and 1666.483 nm were used. The obtained results are compared with the most usual single-line calibration method based on linear regression. This comparison shows that ILS gives a superior performance. Specifically, results indicate that the ILS multiline algorithm is less noise dependent and has a higher reliability than single-line calibration methods.

The paper presents design of low-cost pyroelectric sensor based on polivinylidene fluoride (PVDF) film. The detector element is made of commercially available bioriented poled PVDF foil which thickness is 25 μm. The voltage response of this PVDF sensor to short radiation pulses is studied experimentally. Especially time parameters of the voltage detector response, frequency and temperature characteristic are investigated. Furthermore, influence of load resistance of preamplifier is considered.

The results of spectroscopic and chromatographic investigations of fuel containing the different content of bio-compounds were presented and analysed. The transmittance values at 1744 cm^-1 wave number were used as a measure of total rapeseed oil methyl esters' (RME) concentrations. The microprocessor device for RME content determination was described. The presented dependence of transmittance around 1744 cm^-1 on RME concentration can be applied to the determination of RME content in fuel.

The paper includes discussion on the basic structures of analog signal separators with optoelectronic optocouplers with particular focus on the features significant to provide the linearity of transformation characteristic. It also includes the evaluation of transformation characteristic linearity of a selected optoelectronic current signals separator. For static transformation characteristics, determined experimentally, I₀ = f(I_I) the nonlinearity and approximation errors were compared. Upon comparison of the value of such errors, conclusions were formulated on determining the optimum use of the separator's transmission abilities.

We present the definition and development of a three dimensional high precision measurement system for localisation and control of machine tool's drill based on a Michelson-Morley interferometric configuration and a laser tracking subsystem to redirect the measurement beam onto a retro-reflector positioned in the tool nearness. The system measures the retro-reflector position in real time with 5 microns accuracy up to 2 m/s processing material velocities and it is used to carry out an on-line control feedback of the drill position in the machine tool allowing a drill tool replacement during the fabrication process. The system has been integrated and tested in an especially designed machine tool built for this application.

We present results of a R&D project aimed to produce an environmental surveillance system that, working in wild areas, allows for a real-time observation and control of some ambient factors that could produce a natural disaster. The main objective of the project is the development of an open platform capable to work with several kinds of sensors, in order to adapt itself to the needs of each situation. The detection of environmental risks and management of this data to give a real-time response is the overall objective of the project. The main parts of the system are: 1.- Detection system: capable to perform real-time data and image communication, fully autonomous and designed to consider the environmental conditions. 2.- Alarm management headquaters: reception on real-time of data from the detector network. All the data is analysed to enable a decision about whether there is or not an alarm situation. 3.- Mobile alarm-reception system: portable system for reception of the alarm signal from the headquaters. The project was financed by the Science and Technology Ministry, National Research and Development Programme (TIC2000-0366-P4, 2001-2004).

The theory of periodic phase elements images forming is described based on the method of the coordinate-frequency distribution. The invariant conditions of periodic elements self-images forming which are determined by the ratio of the Fresnel number F₀ to tan(pπ/2) (where p is the FrFT parameter) are investigated in the FrFT domain. The analytic expressions for the calculation of periodic phase elements at different values of the invariant parameter F₀/ tan &Jgr; are obtained. It is shown that the FrFT self-image of elementary cell forms as a result of the finite number of the cross displaced elementary cells superposition. The results of numerical calculations of the periodic phase elements self-images in the FrFT domain are presented. The mechanism of constant intensity levels forming depending on the value of invariant parameter is explained.