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Title: Cryogenic spectrometer for measuring the far-IR to millimeter-wave absorptivity of cosmic analog dusts

We report on the design, construction, and performance of a custom apparatus built to measure the frequency- and temperature-dependent absorptivity of millimeter-wave light by cosmic analog dusts. We highlight the unique challenges faced as well as a few key innovations that are part of the instrument. Among those is an ultra-compact Fourier transform spectrometer. We have measured its effective frequency range and FWHM resolution to be 150–2100 GHz and∼<#comment/>45GHz, respectively. Another innovation is a cold sample positioner whose temperature can be controlled within the range of 3.7–50 K. The use of a pulse-tube cryocooler results in a pulse-synchronous signal that dominates the detector (bolometer) signal. Methods used to address that challenge are also presented.

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Publication Date:
Journal Name:
Applied Optics
Page Range or eLocation-ID:
Article No. 5880
1559-128X; APOPAI
Optical Society of America
Sponsoring Org:
National Science Foundation
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