Case Study: Netherlands Institute for Space Research achieves thermally stable, low-heat calibration for SAFARI detectors with COMSOL Multiphysics

SRON Develops Thermal Calibration System for Deep-Space Telescope

The Netherlands Institute for Space Research (SRON) faced a demanding thermal-management challenge while developing the SAFARI calibration source for the SPICA space telescope: ultrasensitive detectors operating near 4.5 K require a calibration radiator that can be heated to 95–300 K without transferring excess heat or introducing vibrations. To design a thermally insulating, mechanically stiff suspension and low‑dissipation iris/shutter mechanisms, SRON used Comsol Multiphysics simulations from vendor Comsol to model temperature‑dependent material behavior, heat loads, and modal response.

Using Comsol, SRON iterated suspension geometries and settled on a triangular frame held by thin (100 μm) stainless‑steel wires, limiting conducted heat to about 10.17 mW at 150 K (simulation agreed within 0.01 mW) and achieving a 720 Hz resonant frequency. Comsol was also used to optimize the iris coil and housing, producing a design that requires just 38 mA drive current and dissipates 1.6 mW. The Comsol‑guided design produced a thermally stable, low‑noise calibration system whose first tests confirmed the simulations and readiness for integration with SAFARI.

Netherlands Institute for Space Research

Chris de Jonge

Design Engineer