| Autor: |
Sergio Volonte, Matthew Joseph Griffin, Vincent Minier, Roger-Maurice Bonnet, Frank Helmich, Göran Pilbratt, Thijs de Graauw, Vincent Bontems |
| Rok vydání: |
2017 |
| Předmět: |
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| Zdroj: |
Inventing a Space Mission ISBN: 9783319600239 |
| DOI: |
10.1007/978-3-319-60024-6_9 |
| Popis: |
Here we describe the various elements of the Herschel cryogenic concept and its evolution since the first proposal submitted to ESA in 1982, following developments from previous cryogenic missions, and continuous adaptation to the evolving needs of the focal plane instruments, ending in a substantially different concept. A temperature below 2 K was necessary for the Herschel instruments to achieve the required sensitivity. Herschel therefore carried a liquid He cryostat of 2300 l capacity, with the liquid in the superfluid phase at a temperature of 1.6 K. This temperature was optimum for the photoconductive detectors of the PACS spectrometer and for the SIS mixers of the heterodyne HIFI instrument. The detectors of the PACS camera and of the SPIRE camera and spectrometer were bolometers, which required an even lower operating temperature. To achieve this, PACS and SPIRE had their own 3He sorption coolers to reach a temperature of 0.3 K. The telescope was launched warm and, once in orbit, cooled passively down to a temperature of ~85 K. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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