The infrared imaging spectrograph (IRIS) for TMT: electronics-cable architecture

TL;DR

This paper discusses the electrical system design for IRIS, a complex infrared spectrograph for TMT, focusing on cable architecture, cryogenic considerations, and solutions for electrical challenges in a large astronomical instrument.

Contribution

It presents the specific electrical architecture, cable selection, and packaging solutions tailored for IRIS's complex and cryogenic environment, addressing unique engineering challenges.

Findings

Selection of cables and connectors suitable for cryogenic and room temperature environments

Design of cable routing and bulkhead solutions for large detectors

Techniques to mitigate cooling and vibration issues during instrument rotation

Abstract

The InfraRed Imaging Spectrograph (IRIS) is a first-light instrument for the Thirty Meter Telescope (TMT). It combines a diffraction limited imager and an integral field spectrograph. This paper focuses on the electrical system of IRIS. With an instrument of the size and complexity of IRIS we face several electrical challenges. Many of the major controllers must be located directly on the cryostat to reduce cable lengths, and others require multiple bulkheads and must pass through a large cable wrap. Cooling and vibration due to the rotation of the instrument are also major challenges. We will present our selection of cables and connectors for both room temperature and cryogenic environments, packaging in the various cabinets and enclosures, and techniques for complex bulkheads including for large detectors at the cryostat wall.