To demonstrate the feasibility of the fast ignitor scheme, the 100 TW Petawatt Module laser PWM was illuminated on an imploded spherical CD shell, which enhanced neutron yield ~10⁶ for the first time. This is due to the fusion reactions between the energetic deuteron beam and cold dense deuterons. Without PWM, we have observed no neutrons above the detection threshold ~10⁵. Proton rear emission and possible gigagauss scale magnetic fields from 60 TW laser illuminated plastic target are observed in a good agreement with a two-dimensional PIC simulation. The PWM is up graded to the world biggest Petawatt Laser (say PW laser). The out put is 1 Petawatt, which is used also for ultra-intense laser matter interactions above the intensity of 10²0 W/cm².

We have performed pulsed neutron and pulsed laser tests of a CVD diamond detector manufactured from DIAFILM, a commercial grade of CVD diamond. The laser tests were performed at the short pulse UV laser at Bechtel Nevada in Livermore, CA. The pulsed neutrons were provided by DT capsule implosions at the OMEGA laser fusion facility in Rochester, NY. From these tests, we have determined the impulse response to be 250 ps fwhm for an applied E-field of 500 V/mm. Additionally, we have determined the sensitivity to be 2.4 mA/W at 500 V/mm and 4.0 mA/W at 100 V/mm. These values are approximately 2 to 5x times higher than those reported for natural Type IIa diamond at similar E-field and thickness (1mm). These characteristics allow us to conceive of a neutron time-of-flight current mode spectrometer based on CVD diamond. Such an instrument would sit inside the laser fusion target chamber close to target chamber center (TCC), and would record neutron spectra fast enough such that backscattered neutrons and (gamma) rays from the target chamber wall would not be a concern. The acquired neutron spectra could then be used to extract DD fuel areal density from the downscattered secondary to secondary ratio.

Within the framework of the nuclear tests, we have studied the realization of a neutron diagnostic by magnetic spectrometry. We examined the possibility of an establishment near the future laser sources, L.I.L. and L.M.J.. The potential use of this spectrometer is the measurement of the ionic temperature of plasma and would come in complement of the spectrometry per time of flight. This device would be thus interesting on the condition of obtaining a sufficient resolution in energy. One will estimate with which precision this temperature may be given. We will present the codes allowing to entirely simulate the diagnostic from the source to the detector. These codes are organized around a principal code named SPECTRO entirely simulating the magnetic sector. This whole of codes allows the optimization of the characteristics of the apparatus.

The penumbral imaging technique has proven to be ideally suited for neutron imaging. The French CEA has successfully installed a neutron imaging system at the LLE (Rochester-New York) in June 2000. Images of the 14MeV fusion neutrons produced in the target have been recorded in the range 10¹² to 10¹⁴ with a two-point resolution of 45 micrometers. The detector used was a 15cm diameter circular array composed of plastic scintillator elements. For several of the CEA experiments, bubble detectors developed for General Atomics simultaneously recorded neutron images. The SIRINC (Simulation and Reconstruction Imaging Neutron Code) code has been used to unfold neutron images obtained both with the segmented scintillator detector and with the bubble detector. We first describe the experimental setup and detector designs, then compare the sensitivity, quantity of information, and signal to noise ratio for those two detectors. Then raw and unfolded images are presented. The spatial resolution obtained for the unfolded images are estimated and compared for the two detectors types.

Within the framework ofthe CEAIDOE collaboration, an experimental campaign took place in Rochester (N Y in U.S.A.), on the laser installation OMEGA. The aim of this compaign was to test a neutron imaging system. The purpose of this equipment is to form the image of the neutron source which is created by inertial confinement fusion of a deuterium-tritium mixture, in order to determine the space distribution ofthe emission ofthe neutrons. A neutron imaging device, based on the method known as "Penumbral Imaging including a pinhole, a scintillator, a device of transport of image, an image intensifier (Micro Chanel Plate) and a CCD array, was studied at C. E. A. The goal of this report is to study, on one hand, the schielding of the CCD againts the neutrons of the source and the gammas created at the chamber wall due to direct irradiation and, on the other hand, to evaluate the level of the interfering signal neutrons and gamma diffused by the environment. This interfering signal decreases the dynamics of measurement and increases the signal noise ratio. It is thus important to control it well. All calculations were made using the code Monte Carlo MCNP.

Photo-excitation nuclear reactions induced by the 2J, 30 fs, 4x10¹⁰W/cm², 10 Hz LOA laser were optimized with respect to the thickness of the solid target. Using 6 micrometers CH targets, electrons up to 60 MeV have been produced and converted to (gamma) -rays by Bremsstrahlung in a Ta piece. The rate of photo-fission of ²³⁸U, as well as photo- excitation nuclear reactions in Cu, Au and C samples have been measured. More than 10⁶ nuclear reactions were obtained after 60 subsequent laser shots. The high energy electrons are forward focused, within 15 degree(s), as observed from the angular distribution of the activation in Cu. 1% of laser energy was converted to (gamma) -rays with energies higher than 10 MeV.

A search of Nuclear Excitation by Electron Transition (NEET) in ²³⁵U excited in the plasma produced by a 300 mJ, 10 ns laser is presented. Many experimental aspects have been faced to evidence the low rate of NEET excitation of the 76 eV isomeric level in ²³⁵U with a plasma temperature T=25 eV. The experimental limit measured for the transition rate for the 76 eV ²³⁵U^m state is (lambda) _N<2.10^-5s^-1. Several potential upgrades are considered to aim at a measure of the NEET excitation rate in ^235$U.

Areal density ((sigma) R) is a fundamental parameter that characterizes the performance of an ICF implosion. For high areal densities ((sigma) R>0.1 g/cm²), which will be realized in implosion experiments at NIF and LMJ, the target areal density exceeds the stopping range of charged particles and measurements with charged particle spectroscopy will be difficult. In this region, an areal density measurement method using down shifted neutron counting is a promising alternative. The probability of neutron scattering in the imploded plasma is proportional to the areal density of the plasma. The spectrum of neutrons scattered by the specific target nucleus has a characteristic low energy cut off. This enables separate, simultaneous measurements of fuel and pusher (sigma) Rs. To apply this concept in implosion experiments, the detector should have extremely large dynamic range. Sufficient signal output for low energy neutrons is also required. A lithium-glass scintillation-fiber plate (LG-SCIFI) is a promising candidate for this application. In this paper we propose a novel technique based on down shifted neutron measurements with a lithium-glass sctintillation-fiber plate. The details of instrumentation and background estimation with Monte Carlo calculation are reported.

In-column magnetic energy filters have been designed so as to have the central plane of symmetry of magnetic field and anti-symmetry of the imaging electron trajectory to the dispersion direction in order to cancel 2nd order aberrations. A new S filter, on the other hand, has the anti-symmetry to the mid point of the magnetic field and has the symmetry to the imaging trajectory. In the previous filters, the magnets locate only one side of the optical axis, but the symmetry condition of S filter gives a good balancing filter shape to the optical axis of the incident beam. In all of the previous filters, the number of focuses in the x-direction is 3 for the dispersion rays, but its number increases to 4 in the S filter, giving the dispersion of 6 micrometers eV at 300 kV for the practical design and 10 (mu) m/eV for the ideal case.

A compact neutron generator based on D-D or D-T fusion reactions is being developed at the Lawrence Berkeley National laboratory. The deuterium or tritium ions are produced in a radio-frequency (RF) driven multicusp plasma source. Seven beamlets are extracted and are accelerated to energy of 100 keV by means of a three-electrode electrostatic accelerator column. The ion beam then impinges on a titanium coated copper target where either the 2.4 MeV D-D or 13 MeV D-T neutrons are generated by fusion reaction. The development of the neutron tube is divided into three phases. First, the accelerator column is operated at hydrogen beam intensity of 15 mA. Second phase consists of deuterium beam runs at pulsed, low duty cycle 150 mA operation. The third phase consists of deuterium or tritium operation at 1.5 A beam current. Phase one is completed and the results of hydrogen beam testing are discussed. Low duty cycle 150 mA deuterium operation is being investigated. Neutron flux will be measured. Finally the phase three operation and the advance neutron generator designs are described.

A novel design for an electron beam focusing column has been developed at LBNL. The design is based on a low-energy spread multicusp plasma source which is used as a cathode for electron beam production. The focusing column is 10 mm in length. The electron beam is focused by means of electrostatic fields. The column is designed for a maximum voltage of 50 kV. Simulations of the electron trajectories have been performed by using the 2D simulation code IGUN and EGUN. The electron temperature has also been incorporated into the simulations. The electron beam simulations, column design and fabrication will be discussed in this presentation.

Various focused ion beam (FIB) processes, which can generate two- or three-dimensional (2D or 3D) features on surfaces by removing or depositing material, are reviewed for their efficiency. Processes for removing material include direct ion milling, chemical etching with a reactive gas, reactive ion etching, ion implantation with post chemical etch, deposition (simultaneous FIB and gas jet), FIB induced nucleation, and ion resist lithography. Surface material removal and deposition efficiencies (cubic microns per nano- coulomb of ion beam current) are examined, and their ability to form 2D and 3D surface structures is analyzed. In general, the ion lithography processes are the most efficient, whereas direct ion deposition is very inefficient. FIB instrument capabilities are examined including their focused ion beam size and beam current characteristics. These FIB instruments commonly employ field emission LMIS's (liquid metal ion sources), can focus beams to less than 10 nm diameter, and can rapidly mill in the 100 nm beam range. The removal and addition rates of material (cubic microns per second) are then examined for the various surface modification processes using these instruments. Since the milling throughput of FIB Instruments has increased by two orders of magnitude in the last decade, new nanofabrication applications are rapidly unfolding. Direct FIB milling, FIB chemical etching, and FIB deposition are now common processes in the semiconductor industry for circuit modification, defect analysis, and process control. Production applications include thin film magnetic head trimming and aperture fabrication.

In this paper we propose an improved three-dimensional (3D) boundary charge method (BCM) for a composite dielectric system in which insulators, i.e., dielectric materials exist together with conducting electrodes. The method is based on the idea that the composite dielectric system can equivalently be replaced with a conductor system in vacuum by introducing an apparent surface charge density (=true surface charge density + polarization surface charge density), on every conductor-to-dielectric interface and every dielectric-to-dielectric interface. In calculating the apparent surface charge density, whole interfaces are divided into n small surface elements, and the apparent surface (or boundary) charge density on each small surface element is obtained by solving a set of n-dimensional simultaneous linear equations, where the coefficient matrix elements is expressed as a double integral and the diagonal matrix element becomes a singular or nearly singular integral. A high-accuracy and high-speed calculation of the double integral is the key point of the method, and we have succeeded in great improvement of both numerical accuracy and computation time.

The latest version of the particle optics computer aided design code POCAD is presented. This interactive code calculates properties of single pass charged-particle optical systems. The properties of CPO systems are calculated by TRAcking particles through the system and FItting transfer Coefficients to their end coordinates (TRAFIC). This approach allows for a general definition of the optical components in the system, which can be defined by analytical functions, transfer matrices, or full numerical calculations. After giving a general overview of the code, the paper focuses on techniques recently developed for specific applications. These include the direct tracing of particles through electrostatic and magnetic lenses using the axial potential generated by finite element method programs, and also the calculation of Coulomb interactions.

The application of Genetic Algorithms (GAs) to the optimization design method, such as Simplex method and Powell method etc, can determine the final optimum structure and electric parameters of an electron optical system from given electron optical properties, but it may be landed in the localization of optimum search process. The GAs is a novel direct search optimization method based on principles of natural selection and survival of the fittest from natural evolution. Through the reproduction, crossover, and mutation iterative process, GAs can search the global optimum result. We applied the GAs to optimize an electron emission system and an extended field lens (EFL) respectively. The optimal structure and corresponding electrical parameters with a criterion of minimum objective function value, crossover radius for electron emission system and spherical aberration coefficient for EFL, have been searched and presented in this paper. The GAs, as a direct search method and an adaptive search technique, has significant advantage in the optimization design of electron optical systems.

Boundary element method is used for the purpose of ray tracing of charged particles. The results presented here are based on a commercially available package; Lorentz, by Integrated Engineering Software; a.k.a. Enginia Research Inc. First, a brief description of different numerical methods is presented, followed by some known theoretical examples. In all cases, excellent agreement between the theoretical results and the numerical ones is observed. Several of the examples deal with the space charge issue. Child's law and Langmuir-Blodgett's are used to verify these results. Also an example, 743 Test, of launching a particle close to a field discontinuity is presented to show the power of BEM method when it comes to dealing with extreme ratios in the dimensionality (>10⁶) within a device.

Artificial neural network is used in the inverse design of an electron gun's main lens in this paper. The relationship between electron spot on the screen and the structure of the main lens is investigated. According to the requirement of the spot on the screen, the structure of the main lens is investigated. According to the requirement of the spot on the screen, the structure of the main lens can be obtained through the trained network in a short time. The complex electron optic simulation can be avoided. It shows that the artificial neural network method is an effective tool to solve the inverse designing problem in the electron optic system.

Vertically-aligned carbon nanotubes (VA-CNT) are extremely attractive for use as field emission sources. The field emission characteristics of VA-CNTs are determined by the electric field strength on the CNT apexes, and therefore depend strongly on the geometrical parameters such as radius of curvature of the CNT apex, an average density of CNTs and non-uniformity of CNT lengths. This paper describes a computer simulation of electric field analysis for VA-CNTs by means of an improved 3D boundary charge method, where the VA-CNTs are modeled by 9X9 CNTs standing vertically on the cathode substrate. We have calculated the electric field strength on the CNT apex for various geometrical parameters of VA-CNTs. It has been found that the electric field on the CNT apex is inversely proportional to the radius of curvature of the CNT apex, and significantly decrease when the CNT density exceeds 10⁰/cm².

This paper describes a computer simulation method and a computing model for electric field analysis of a vertically- aligned carbon nanotube (VACNT) system by means of an improved three-dimensional boundary charge method (3-D BCM). A real VACNT system where the number of CNTs is as large as ten millions per 1 mm² is modeled by 9x9 CNTs standing vertically on the cathode substrate. The whole conducting surface consisting of CNTs, the cathode substrate and the anode plate are divided into about 4000 small surface elements, which are found to be enough for reasonable accuracy in electric field calculation. It has also been confirmed that the electric field strength at the CNT apex in the real VACNT system is well represented by the electric field strength at the apex of the central CNT of the 9x9 CNT computing model.

Manufacturing irregularities and misalignments in electron guns for CRTs degrade the resolution, especially at high brightness. Using simulations of an electron gun that are 3D and include space charge, the spot size, which directly determines resolution, is calculated. These simulations are then used to calculate the sensitivies of spot size to misalignments, part-size tolerances, and lens out-of- roundness. Sensitivies for the manufacture of electron guns are defined and calculated. These sensitivities connect misalignments, part-size tolerances, and lens out-of- roundness to beam displacement in the lens, to beam size in the lens, and to focus astigmatism, respectively. With specifications for tolerances and misalignments, the distribution of spot sizes expected in manufacturing CRTs can be calculated. The importances of the specifications are prioritized in pareto charts. Logistics show which construction irregularity groups are benign and which ones threaten production crises. While monochrome electron guns are used to illustrate these concepts, they have been used for color electron guns and nanolithography, and they are applicable to many electron-optical systems.

This paper describes a new numerical method capable of handling the scattering, the accumulation and the diffusion of electrons and holes in the specimen with 2D structure in a section, perpendicular to the top surface, made up of metals, semiconductors and insulators. The method comprises three parts; 1. Monte Carlo calculations for the scattering of electrons, 2. Numerical techniques for determining the accumulation of electrons and holes and the potentials, 3. Semiconductor Device Simulation techniques capable of modeling and analyzing the electron diffusion distribution. Preliminary testing on the performance is done, and the result shows that this method give essential information to understand charging characteristics such as a distribution of electrons and holes, and potentials in a stationary equilibrium. The details of the model are described. And the computation of the potentials in a specimen using this method and the conventional Monte Carlo calculation are compared. Examples for extended application are also shown.

An electromagnetic system with matching centers of deflection in any arbitrary direction of charged particle beam is proposed. Analytical expressions for electrostatic and magnetic scalar potential distributions for such systems made of four, six and eight electrodes-poles were obtained in two-dimensional approximation. Values of feeding potential needed for improvement of field homogeneity were found for the six electrode-pole systems. Conditions of the first order achromatism for the deflecting, focusing and correcting systems with the transversal fields have been written in general form. Edge field distribution along optical axis has been calculated numerically for finite length deflectors and empirical formula approximating this distribution has been derived. Beam central trajectory parameters were calculated for electrostatic, magnetic and for systems with common ratio of the electrostatic and magnetic components, providing achromatic deflection in small work region. Other ratios of these components providing expansion of region of the achromatic deflection up to 20⁰-25⁰ and high er degree of the linear deflection were found. Advantages of the proposed deflectors are described.

We have studied the influence of the target properties on laser-accelerated proton and ion beams generated by the LULI multi-terawatt laser. A strong dependence of the ion emission on the surface conditions, conductivity, shape and material of the thin foil targets were observed. We have performed a full characterization of the ion beam using magnetic spectrometers, Thompson parabolas, radiochromic film and nuclear activation techniques. The strong dependence of the ion beam acceleration on the conditions on the target back surface was found in agreement with theoretical predictions based on the target normal sheath acceleration (TNSA) mechanism. Proton kinetic energies up to 25 MeV have been observed.

While not obvious, deflection aberration is a key aberration in Cathode Ray Tube (CRT) design. A new concept in electron beam deflection with electric fields, originally proposed in 1997, is now being tested in the laboratory. Using a beam injected off the axis of symmetry, deflection aberrations are predicted to be 10 fold reduced compared to symmetrical injection. This would be less than magnetic deflection aberrations. If the invention proves to be valid, important improvements are possible in CRT brightness, resolution, energy consumption, and footprint reduction. As one example, reducing deflection aberrations allows larger beam diameters in the deflection plane as well as large deflection angles. This will reduce space charge spread, allowing larger beam currents and/or smaller focused spot size. Improved medical imaging displays could be built. For another example, much of the energy consumed in a magnetically deflected CRT display is associated with deflection. Electric deflection has a significant advantage in energy consumed compared to magnetic deflection. With 400 million CRTs in daily use in the US consuming 0.54 quads, there is a large incentive to reduce power consumption in CRTs particularly so since excess heat produced adds to office air conditioning loads.

The resolution of a low-voltage scanning electron microscope is limited by the chromatic and spherical aberration of the objective lens. Any significant improvement of the resolution requires an aberration corrector or monochromator. Recently, correction of both C_c and C_s has been demonstrated in a SEM, using a combination of magnetic and electrostatic quadruples and octuples. This paper presents an alternative and purely electrostatic design which, like most quadrupole-octuple correctors, is based on the concept of creating a stigmatic path and correcting C_c in the two line foci. We propose a combination of strongly oscillating mono- and quadruple fields as dispersive elements. Our arrangement of the mono- and quadruple fields creates a thick non-focusing correcting elements, which corrects for C_c in one plane, while these fields act as a telescope (with magnification M=+/- 1) in the other plane. The telescopic properties of the correcting element in both planes reduce the chromatic magnification aberration of the corrector to acceptable proportions. To model our corrector realistically, the electrostatic potential has been computed for a 3D electron geometry with the EO-3D package from MEBS. From this the electrostatic potential has been computed for a 3D electrode geometry with the EO-3D package from MEBS. From this potential we extracted axial field functions for the monopole up to octuple fields. Ray tracing with these axial fields using MEBS's MULTIPOL package yields all aberrations up to fifth order. The numerical calculations show a resolution enhancement by a factor of 2 with a C_c and C_s corrector that is based on our novel correcting elements.

At present, the throughput of projection-type charge particle lithography systems, such as PREVAIL and SCALPEL, is limited primarily by the combined effects of field curvature in the projection lenses and Coulomb interaction in the particle beam. These are fundamental physical limitations, inherent in charged particle optics, so there seems little scope for significantly improving the design of such systems, using conventional rotationally symmetric electron lenses. This paper explores the possibility of overcoming the field aberrations of round electron lense, by using a novel aberration corrector, proposed by Professor H. Rose of University of Darmstadt, called a hexapole planator. In this scheme, a set of round lenses is first used to simultaneously correct distortion and coma. The hexapole planator is then used to correct the field curvature and astigmatism, and to create a negative spherical aberration. The size of the transfer lenses around the planator can then be adjusted to zero the residual spherical aberration. In a way, an electron optical projection system is obtained that is free of all primary geometrical aberrations. In this paper, the feasibility of this concept has been studied with a computer simulation. The simulations verify that this scheme can indeed work, for both electrostatic and magnetic projection systems. Two design studies have been carried out. The first is for an electrostatic system that could be used for ion beam lithography, and the second is for a magnetic projection system for electron beam lithography. In both cases, designs have been achieved in which all primary third-order geometrical aberrations are totally eliminated.