SMART: The KOSMA Sub-Millimeter Array Receiver for Two frequencies
SMART: The KOSMA Sub-Millimeter Array Receiver for Two frequencies
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SMART：用于两个频率的 KOSMA 亚毫米阵列接收器
DOI：
10.1117/12.459669
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
B. Vowinkel
中科院分区：
文献类型：
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作者：
U. Graf;S. Heyminck;E. Michael;Š. Stanko;C. Honingh;K. Jacobs;R. Schieder;J. Stutzki;B. Vowinkel
我们介绍了我们新的双频SIS阵列接收器SMART自2001年9月以来在瑞士泽马特附近Gornergrat的Kosma 3m望远镜上运行的第一批结果。接收器由两个2×4像素子阵列组成。一个子阵列的工作频率为490 GHz，另一个子阵列的工作频率为810 GHz。这两个子阵指向天空中的相同位置。因此，我们可以同时在两个频率上观测到八个空间位置。在运行的第一年，我们只安装了每个子阵的一半，即在每个频率上一行4个混频器。接收器采用非常紧凑的设计，适合我们的小型天文台。为了实现这一点，我们将大部分光学元件放置在环境温度下，接受光学表面热发射造成的非常小的灵敏度损失。该光学系统包括一个K镜型镜面旋转器、两个Martin-Puplett双工器和两个固态本振振荡器，它们使用准直傅里叶光栅进行多路复用。为了减少对光学对准的需求，我们使用数控铣削技术整体加工大型光学组件。我们使用标准的Kosma固定调谐波导SIS混频器，其中Nb结的频率为490 GHz，以及类似的Nb混频器的Al调谐电路，频率为810 GHz。本文简要介绍了该仪器的前端设计，并给出了焦平面波束图、接收器灵敏度测量和用新仪器获得的第一批天文数据。
We present the first results obtained with our new dual frequency SIS array receiver SMART The instrument is operational since September 2001 at the KOSMA 3m telescope on Gornergrat near Zermatt/Switzerland. The receiver consists of two 2×4 pixel subarrays. One subarray operates at a frequency of 490 GHz, the other one at 810 GHz. Both subarrays are pointed at the same positions on the sky. We can thus observe eight spatial positions in two frequencies simultaneously. For the first year of operation we installed only one half of each subarray, i.e. one row of 4 mixers at each frequency. The receiver follows a very compact design to fit our small observatory. To achieve this, we placed most of the optics at ambient temperature, accepting the very small sensitivity loss caused by thermal emission from the optical surfaces. The optics setup contains a K-mirror type image rotator, two Martin-Puplett diplexers and two solid state local oscillators, which are multiplexed using collimating Fourier gratings. To reduce the need for optical alignment, we machined large optical subassemblies monolithically, using CNC milling techniques. We use the standard KOSMA fixed tuned waveguide SIS mixers with Nb junctions at 490 GHz, and similar Nb mixers with Al tuning circuits at 810 GHz. We give a short description of the front end design and present focal plane beam maps, receiver sensitivity measurements, and the first astronomical data obtained with the new instrument.