Measurement of mechanical losses in the carbon nanotube black coating of silicon wafers
The successful detection of gravitational waves from astrophysical sources carried out by the laser interferometric detectors LIGO and Virgo have stimulated scientists to develop a new generation of more sensitive gravitational wave detectors. In the proposed upgrade called LIGO Voyager, silicon test masses will be cooled to cryogenic temperatures. To provide heat removal from the test masses when they absorb the laser light one can increase their thermal emissivity using a special black coating. We have studied mechanical losses in a carbon nanotube black coating deposited on silicon wafers. The additional thermal noise associated with mechanical loss in this coating was calculated using a value of the product of the coating Young's modulus and the coating mechanical loss angle determined from the measurements. It was found that at temperatures of about 123 K, the additional thermal noise of the LIGO Voyager test mass caused by the carbon nanotube black coating deposited on its barrel is less than the noise associated with the Acktar Black coating and is 20 times less than the noise due to the optical high reflective (HR) coating of the test mass.
© 2019 IOP Publishing. Received 8 January 2019, revised 28 October 2019; Accepted for publication 31 October 2019; Published 29 November 2019. The authors gratefully acknowledge the support of the Russian Science Foundation Grant No. 17-12-01095 and the MSU Fund at TAPIR. LIGO was constructed by the California Institute of Technology and Massachusetts Institute of Technology with funding from the National Science Foundation and operates under cooperative agreement PHY-0757058. This paper has LIGO Document Number LIGO-P1800369.
Accepted Version - Prokhorov+et+al_2019_Class._Quantum_Grav._10.1088_1361-6382_ab5357.pdf
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