Journal Article

PUBDB-2024-08006

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Measurement of the thermal accommodation coefficient of helium on a crystalline silicon surface at low-temperatures

Franke, A. (Corresponding author)CFEL*Extern* ; Sueltmann, N. F.Extern* ; Reinhardt, C. (Corresponding author)DESY* ; Croatto, S.DESY* ; Schaffran, J.DESY* ; Masalehdan, H.Extern* ; Lindner, A.DESY* ; Schnabel, R.Extern*

2024
IOP Publ. Bristol

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Please use a persistent id in citations: doi:10.1088/1361-6382/ad7184  doi:10.3204/PUBDB-2024-08006

Report No.: arXiv:2402.11977

Abstract: Proposals for next-generation gravitational wave observatories include cryogenically cooled 200 kg test mass mirrors suspended from pendulums and made of a crystalline material such as crystalline silicon. During operation of the observatories, these mirrors undergo heating due to the absorption of laser radiation of up to a watt. Low noise cooling techniques need to be developed. Low-pressure helium exchange gas at 5 K might contribute to the challenging task. Here, we report the measurement of the helium accommodation coefficient $\alpha(11\,\mathrm{K} \lt T \lt 30\,\mathrm{K})$, which is the probability that a helium atom thermalises with a surface at a given temperature when reflected from it. We find $\alpha(T) \gt 0.7$ for temperatures ${\lt}20$ K, which increases the cooling power compared to recently used assumptions. The idea of free molecular flow helium gas cooling is thus supported and might find application in some observatory concepts.

Note: 12 pages, 5 figures

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Contributing Institute(s):

1. Any Light Particle Search (ALPS)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF4-611) (POF4-611)
2. DFG project G:(GEPRIS)390833306 - EXC 2121: Quantum Universe (390833306) (390833306)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2024

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; National-Konsortium ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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Linked articles:

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Preprint Franke, A. (Corresponding author)CFEL*Extern* ; Sültmann, N. ; Reinhardt, C.DESY* ; Croatto, S.DESY* ; Schaffran, J.DESY* ; Masalehdan, H. ; Lindner, A.DESY* ; Schnabel, R.
Measurement of the thermal accommodation coefficient of helium on a crystalline silicon surface at low-temperatures
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