1. Cryogenic spectrometer for measuring the far-IR to millimeter-wave absorptivity of cosmic analog dusts
- Author
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Thushara Perera, S. M. Nam, R. A. Roesner, R. Zhang, R. Dorsey, B. Phan, C. Ussery, R. K. Schonert, K. C. North, L.-J. Liu, and K. Lopez
- Subjects
Physics ,Spectrometer ,business.industry ,Detector ,Bolometer ,Molar absorptivity ,Cryocooler ,Signal ,Atomic and Molecular Physics, and Optics ,law.invention ,Optics ,law ,Extremely high frequency ,Electrical and Electronic Engineering ,business ,Engineering (miscellaneous) ,Effective frequency - Abstract
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 ∼ 45 G H z , 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.
- Published
- 2021