Temperature systems based on Peltier-elements for the use in a Thermal Vacuum Chamber and a Bakeout Facility for space laser components

Date

7/12/2021

Journal Title

Journal ISSN

Volume Title

Publisher

50th International Conference on Environmental Systems

Abstract

We report on the implementation of two different Peltier-element-based temperature systems for vacuum chambers. The first of these systems is integrated into a thermal vacuum chamber to achieve temperatures between - 40�C to + 50�C with a temperature gradient of 1 K/min. This system enables thermal cycling tests of (fiber-) optical components for a pre study of the LISA mission. The system is set up with commercially available components and low complexity to be easily adapted to the given vacuum chamber. The lowest temperature achieved in vacuum using single-stage, water-cooled Peltier-elements is - 44,2�C. Thermal cycling with a temperature gradient of 1 K/min for temperatures between - 40� to + 50�C was successfully tested over two weeks showing no degradation of the Peltier-elements. A comparison of our Peltier-element-based temperature system to an LN2-based system showed higher stability in the temperature plateaus and for the temperature gradient. In the second system a cold trap based on two-stage Peltier-elements has been set up. This system is integrated in a Bakeout Facility, which decreases the molecular contamination on flight hardware of solid state laser components for the Franco-German climate mission MERLIN. To prevent cross contaminations, the challenge for this system lies in the choice of very low outgassing components. No plastics, silicon, thermal paste or foil are used. The Peltier-elements are directly soldered between the water-cooled heat sink and the cold surface plates using a soldering method, that was developed at ILT. The lowest temperature achieved in vacuum at the cold surface plates is - 44,6�C and is only limited by the temperature range of the TEC Controllers. Long-term measurements of this system at its working temperature of -30�C show a stability of � 0,1�C over seven days.

Description

Patricia Betz, Fraunhofer Institute for Laser Technology
Jonas E�er, Fraunhofer Institute for Laser Technology
Christian Gr�fe, Fraunhofer Institute for Laser Technology
Jean Burghard Plum, Fraunhofer Institute for Laser Technology
ICES203: Thermal Testing
The 50th International Conference on Environmental Systems was held virtually on 12 July 2021 through 14 July 2021.

Keywords

Peltier-element-based temperature system, Thermal Vacuum Chamber, Bakeout Facility, Flight hardware laser components, Optical fiber components

Citation