25 July 2014 Performance characterization of UV science cameras developed for the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP)
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The NASA Marshall Space Flight Center (MSFC) has developed a science camera suitable for sub-orbital missions for observations in the UV, EUV and soft X-ray. Six cameras will be built and tested for flight with the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP), a joint National Astronomical Observatory of Japan (NAOJ) and MSFC sounding rocket mission. The goal of the CLASP mission is to observe the scattering polarization in Lyman-α and to detect the Hanle effect in the line core. Due to the nature of Lyman-α polarizationin the chromosphere, strict measurement sensitivity requirements are imposed on the CLASP polarimeter and spectrograph systems; science requirements for polarization measurements of Q/I and U/I are 0.1% in the line core. CLASP is a dual-beam spectro-polarimeter, which uses a continuously rotating waveplate as a polarization modulator, while the waveplate motor driver outputs trigger pulses to synchronize the exposures. The CCDs are operated in frame-transfer mode; the trigger pulse initiates the frame transfer, effectively ending the ongoing exposure and starting the next. The strict requirement of 0.1% polarization accuracy is met by using frame-transfer cameras to maximize the duty cycle in order to minimize photon noise. The CLASP cameras were designed to operate with ≤ 10 e-/pixel/second dark current, ≤ 25 e- read noise, a gain of 2.0 +- 0.5 and ≤ 1.0% residual non-linearity. We present the results of the performance characterization study performed on the CLASP prototype camera; dark current, read noise, camera gain and residual non-linearity.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
P. Champey, P. Champey, K. Kobayashi, K. Kobayashi, A. Winebarger, A. Winebarger, J. Cirtain, J. Cirtain, D. Hyde, D. Hyde, B. Robertson, B. Robertson, D. Beabout, D. Beabout, B. Beabout, B. Beabout, M. Stewart, M. Stewart, } "Performance characterization of UV science cameras developed for the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP)", Proc. SPIE 9144, Space Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ray, 914439 (25 July 2014); doi: 10.1117/12.2057321; https://doi.org/10.1117/12.2057321


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