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A broadband thz receiver for low background space applications
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Hagmann, C. Timbie, P. Clapp, A. C. Richards, P. L. Benford, D. J. |
| Copyright Year | 1992 |
| Description | We have developed a sensitive bolometric receiver for low background space applications. In a 10 percent bandwidth at 1 THz, this receiver is approximately 100 times more sensitive than a quantum limited heterodyne receiver with a 1 GHz IF bandwidth. This receiver is designed to be used for the long wavelength band (200-700 microns) in the MIPS instrument on NASA's SIRTF satellite. The bolometers are cooled to 100 mK by an adiabatic demagnetization refrigerator. Roughly 60 g of cesium chrome alum salt is partially demagnetized to 100 mK, followed by a slow regulated downramp to compensate for the heat leak. The hold time of the ADR system is about 18 hours with a temperature stability of delta T(sub rms) approx. equals 10 micro-K. The composite bolometers have electrical responsivities of 10(exp 9)V/W and electrical NEP's of about 3x10(exp -17) W/square root of Hz. The bolometer signals are read out by JFET preamplifiers located on the helium plate and operated at 120 K. We have addressed a number of space qualification issues, such as the development of an analog magnet controller, construction of a cryogenic shake-table for bolometers and selection of the paramagnetic salt CCA which can survive a bakeout at 50 C. The receiver is scheduled to be flown in the spring of 1992 on a balloon telescope. This flight has a dual purpose. One is to provide realistic test of the capabilities of the new receiver. The other is to search for anisotropies in the cosmic microwave background on scales of a few degrees. |
| File Size | 468190 |
| Page Count | 10 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19930018593 |
| Archival Resource Key | ark:/13960/t2799345g |
| Language | English |
| Publisher Date | 1992-01-01 |
| Access Restriction | Open |
| Subject Keyword | Communications And Radar Satellite-borne Instruments Refrigerators Broadband Receivers Photometers Space Infrared Telescope Facility Bolometers Spaceborne Telescopes Thermal Stability Astronomical Photometry Cesium Compounds Submillimeter Waves Noise Temperature Preamplifiers Alum Magnetic Cooling Demagnetization Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
