Translator Disclaimer
15 July 2010 ALMA front-end verification using dry cold load
Author Affiliations +
We describe the design and characterisation of a cryogenic millimetre/sub-millimetre wave calibration load, cooled by use of a closed cycle refrigerator that is used to test the performance of the ALMA receiver front-end system. Use of the refrigerator removes the need for liquid cryogen (nitrogen) cooling and allows for long duration, and unattended operation independent of orientation angle. Key requirements of the load include provision of a well-characterised and constant brightness temperature over a wide frequency range (from ~100 GHz to ~1 THz) polarisation insensitivity, high emissivity and mechanical stability. Test and verification of the load performance characteristics is achieved by using several measurement techniques; these are presented and compared with measurements made using a liquid cryogen load (cooled reference).
© (2010) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yoonjae Lee, Brian Ellison, Peter Huggard, Mark Harman, Abdelhakim Boughriet, Wojciech Bartynowski, Matthew Oldfield, Nigel Morris, Peter Hekman, and Gie Han Tan "ALMA front-end verification using dry cold load", Proc. SPIE 7741, Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy V, 77412K (15 July 2010);

Back to Top