arXiv subjects

Luis Neumeier

Publications and source records attributed to Luis Neumeier.

2 recordsLinked to original sources

arXiv2026

The MICADO first light imager for the ELT: an overview of the RAM analysis and consequent design and maintenance strategy

MICADO is a cryogenic near infrared Multi-AO Imaging Camera and Spectrometer developed for the first light operations at the ELT. It will operate in a "Standalone" configuration with a Single Conjugate Adaptive Optics module for a nominal period of two years. After this time, the system will be re-arranged in the "MICADO-MORFEO" configuration, being able to switch between the SCAO and a Multi Conjugate Adaptive Optics module in the later phase of the project. The lifetime requirement of minimum ten years, together with other demanding requisites about its availability and reliability triggered a meticulous FMECA analysis mainly focused on developing robust maintenance strategies. In this paper, we outline the assumptions and the boundaries of the MICADO RAM analysis, a collaborative effort involving the Max Planck Institute for the Extraterrestrial Physics, the Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique and the European Southern Observatory, starting from the input provided by all MICADO partners. We describe how RAM aspects drove some design choices as well as the selection and use of components. We report the preventive and predictive maintenance strategies, which we considered to minimize the risk of instrument downtime in the high cost operational context of the ELT.

astro-ph.IM↗

arXiv2024

The MICADO first light imager for the ELT: design and performance of the Focal Plane Mechanism prototype

MICADO is a first-generation instrument for the ELT. It will provide diffraction-limited imaging in standard, astrometric, and coronagraphic modes and long-slit spectroscopy at near-infrared wavelengths. The core of the MICADO instrument is its cryostat, which cools the internal optical and mechanical subsystems to 80 K. Following a light ray entering the cryostat through the entrance window, the first mechanism it encounters is the Focal Plane Mechanism. It consists of two independent movable devices mounted in one assembly: the aperture wheel and the focal plane wheel. The primary purpose of the aperture wheel is to rapidly block the light path, which is needed to mitigate persistence on the detectors. The focal plane wheel holds field stops, calibration masks, slits, and coronagraphs. The positioning requirements for the wheel are dominated by the coronographic masks demanding a 15 $\mu$m RMS repeatability. To fulfill this specification and avoid mechanical wear in the drive, a novel magnetically coupled gear system was developed at the Max Planck Institute for Extraterrestrial Physics (MPE). A magnetically coupled worm gear uses magnetic forces to transmit torque from the motor to the driven component without direct mechanical contact. This paper describes the design and performance of the magnetic drive and the first results of the focal plane wheel prototype tests in a cryogenic environment.

astro-ph.IM↗