Emissivity Estimation of Mariner Test Mass Barrel Coatings

Document #:

LIGO-T2200178-v2

Document type:

T - Technical notes

Abstract:

The Laser Interferometer Gravitational Wave Observatory (LIGO) will undergo the cryogenic Voyager upgrade to increase detector sensitivity, allowing gravitational wave astronomers to learn more information about astronomical events in the field of multimessenger astrophysics. This upgrade will require efficient cooling of the test mass, in part through high thermal emissivity coatings applied to the barrel surface. We used Markov Chain Monte Carlo (MCMC) analysis to build an accurate model of the cryostat system and to fit the test mass emissivity value to noisy data from the system cooldown. These results showed that the cryostat system used was both radiatively and conductively cooled. We found that the emissivity of a silicon wafer was 0.72 +/- .04, showing that the cleaning method was insufficient for this sample. This analysis will be applied to emissivity tests of various high thermal emissivity coatings that potentially can be used in the LIGO Voyager upgrade.

Files in Document:

• Final_Report_Clare_Nelle.pdf (3.2 MB)

Other Files:

• SURF22_proposal_CN.pdf (114.5 kB)
• CN Interim Report 1 (Interim_report_1.pdf, 1.1 MB)
• CN Interim Report 2 (Interim_report_2 (1).pdf, 3.4 MB)
• Clare_Nelle_LIGO_SURF_FinalPresentation_T2200178 (Emissivity Estimation for Radiative CryoCooling [Auto...pptm, 10.8 MB)

Topics:

• Basic R&D

Authors:

• Clare Nelle
• Radhika Bhatt
• Christopher Wipf
• Rana Adhikari

Keywords:

SURF22 thermal modeling MCMC temperature control emissivity

Notes and Changes:

Clare Nelle's 2022 SURF project

Referenced by:

• LIGO-T2200355: Final reports from LIGO SURF program, Summer 2022