Paper 13100-188
Paper 13100-188
HARMONI at ELT: verification tests of opto-mechanical mounts for HARMONI pre-optics in cryogenic environment
On demand | Presented live 19 June 2024 
Abstract
HARMONI is the high angular optical and near-IR integral field spectrograph (IFS) for the ELT. The instrument covers a large spectral range from 470 to 2450nm with resolving powers from 3300 to 18000 and spatial sampling from 60 to 4mas. A workhorse instrument designed to operate in two Adaptive Optics modes - Single-Conjugate Adaptive Optics (SCAO, including a High Contrast capability) and Laser Tomography Adaptive Optics (LTAO) - or without adaptive optics. HARMONI project is now finishing phase C, ready for Final Design Reviews of all subsystems.
The Instrument Pre-Optics (IPO) is one of the HARMONI subsystems. It distributes the telescope light received from the adaptative optics systems. The main objective of the IPO is to format the field for the selected spatial scales feeding the Integral Field Unit (IFU). IPO is under the responsibility of the Institute of Astrophysics of the Canary Islands (IAC). This optical subsystem implements 30 Opto-mechanical mounts working at cryogenic temperatures. The mounts may be classified into two types based on the features of the optics they support: (1) Sprung Kinematic Mount (SKM) for flat mirrors, and (2) Thermally Compensated Kinematic Sprung Mounts (TCKSM) for power mirrors (toroidal mirrors, offaxis parabolas, and cameras). Designed to maintain optical alignment at cryogenic temperatures, the mounts maintain optical surface deformation within the limits specified by the error budget, ensuring compliance with requirements even worst-case scenarios.
This work describes the verification tests performed to the engineering models of the Opto-mechanical mounts of the IPO to validate compliance with the sub-system optical and mechanical requirements at both room and cryogenic temperatures.
The Instrument Pre-Optics (IPO) is one of the HARMONI subsystems. It distributes the telescope light received from the adaptative optics systems. The main objective of the IPO is to format the field for the selected spatial scales feeding the Integral Field Unit (IFU). IPO is under the responsibility of the Institute of Astrophysics of the Canary Islands (IAC). This optical subsystem implements 30 Opto-mechanical mounts working at cryogenic temperatures. The mounts may be classified into two types based on the features of the optics they support: (1) Sprung Kinematic Mount (SKM) for flat mirrors, and (2) Thermally Compensated Kinematic Sprung Mounts (TCKSM) for power mirrors (toroidal mirrors, offaxis parabolas, and cameras). Designed to maintain optical alignment at cryogenic temperatures, the mounts maintain optical surface deformation within the limits specified by the error budget, ensuring compliance with requirements even worst-case scenarios.
This work describes the verification tests performed to the engineering models of the Opto-mechanical mounts of the IPO to validate compliance with the sub-system optical and mechanical requirements at both room and cryogenic temperatures.
Presenter
Instituto de Astrofísica de Canarias (Spain)
My professional journey commenced in 2001 when I joined the Instituto de Astrofísica de Canarias (IAC) as a mechanical engineer. In the early years, I played a pivotal role in the design, calculation, and AIV processes of the infrared spectrographs developed at the IAC, including projects such as LIRIS, EMIR, and GRIS. Subsequently, I actively participated in the FP6 design studies for the Extremely Large Telescope (ELT). This phase involved my contributions to VLT MASSDIMM, VLT SCIDAR, WEB, APE, and the design proposal for the M1 mount. After that, I contributed to specific work packages for the European Solar Telescope (EST). Evolving into a senior engineer, I became an integral part of the design team for the GTCAO LGS laser launch telescope and after that, I assumed responsibility for the Pre-Optics subsystem of the HARMONI instrument designed for the ELT. Presently, I am the head of the Mechanical Engineering department of the IAC.