Thermal filtering for large aperture cryogenic detector arrays
Thermal filtering for large aperture cryogenic detector arrays
复制标题
大孔径低温探测器阵列的热过滤
DOI：
10.1117/12.673159
复制
发表时间：
2006
影响因子：
2
通讯作者：
P. Ade
中科院分区：
文献类型：
--
作者：
C. Tucker;P. Ade
用于宽视场天文应用的大型探测器阵列的最新进展需要使用大孔径低温恒温器窗口。一个重要的后果是致冷剂上的热负荷和到达探测器的杂散热发射的显着增加。我们已经发现，这种不需要的辐射的很大一部分来自金属网抑制滤波器的介电基板吸收的热功率的再发射。为了克服这个问题，我们开发了一种热过滤器，它优先反射 10μm 热峰附近的辐射。这些滤光片在这些波长下基本上没有吸收，因此发射可以忽略不计，同时允许所需的亚毫米波段的高传输。我们在此报告现有金属网过滤器技术的热问题，并提供新过滤器的性能数据。作为概念证明，我们提供了中孔径仪器 (QUaD1) 的数据，该仪器采用直径 200 毫米的窗口，带或不带热滤光片。
Recent advances in the development of large format detector arrays for wide field astronomical applications have required the use of large aperture cryostat windows. An important consequence is the significant increase in thermal loading on the cryogens and in the stray thermal emission reaching the detectors. We have identified that a significant part of this unwanted radiation comes from re-emission of thermal power absorbed by the dielectric substrate of the metal mesh rejection filters. To overcome this we have developed a thermal filter, which preferentially reflects radiation near the 10μm thermal peak. These filters have essentially no absorption, and hence negligible emission, at these wavelengths whilst allowing high transmission of the wanted sub-millimetre bands. We report here on thermal problems with existing metal mesh filter technology and give performance data for the new filters. As a proof of concept we present data for a medium aperture instrument (QUaD1), which utilises a 200mm diameter window, both with and without thermal filters.