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29 July 2016 Array controller system with cryogenic pre-amplifiers for MIMIZUKU
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MIMIZUKU is a mid-infrared imager and spectrograph being developed for the University of Tokyo Atacama Observatory (TAO) 6.5-m telescope (PI: Y. Yoshii). To fully utilize a high atmospheric transmission of the Chajnantor site, MIMIZUKU covers a wide wavelength range from 2 to 38 μm with three array detectors: a HAWAII-1RG HgCdTe 1024 × 1024 array with a 5 μm cutoff manufactured by Teledyne, an Aquarius Si:As IBC 1024 × 1024 array by Raytheon, and a MF-128 Si:Sb BIB 128 × 128 array by DRS. We have newly developed an array controller system to operate these multiple arrays. A sampling rate higher than 0.5 MHz is required to prevent from saturation of their wells in broad-band imaging observations with MIMIZUKU due to high thermal background flux. Such high speed signals are dulled when passing through lines from the arrays to readout circuits. To overcome this problem, we have developed high-speed cryogenic buffer pre-amplifier circuits with commercial GaAs MESFETs, instead of Si JFETs, which are generally used in buffer amplifiers at cryogenic temperatures. The cryogenic buffer circuits are installed on an outer wall of the optical bench of MIMIZUKU at 20 K. We have measured readout noises of the array controller system including the cryogenic buffers in a test cryostat and room temperature circuits and confirmed that input referred noises of the system are lower than the specification value of the readout noise of the Aquarius array.
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
K. Okada, S. Sako, T. Miyata, T. Kamizuka, R. Ohsawa, M. S. Uchiyama, K. Mori, J. Yamaguchi, K. Asano, and M. Uchiyama "Array controller system with cryogenic pre-amplifiers for MIMIZUKU", Proc. SPIE 9915, High Energy, Optical, and Infrared Detectors for Astronomy VII, 991527 (29 July 2016);

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