| タイトル | Performance Characterization of UV Science Cameras Developed for the Chromospheric Lyman-Alpha Spectro-Polarimeter |
| 本文（外部サイト） | http://hdl.handle.net/2060/20140011800 |
| 著者（英） | Robertson, Bryan; Cirtain, Jonathan; Winebarger, Amy; Beabout, Dyana; Champey, Patrick; Beabout, Brent; Kobayashi, Ken; Hyde, David; Stewart, Mike |
| 発行日 | 2014-06-13 |
| 言語 | eng |
| 内容記述 | 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-alpha and to detect the Hanle effect in the line core. Due to the nature of Lyman-alpha polarization in 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 percent 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 percent polarization accuracy is met by using frame-transfer cameras to maximize the duty cycle in order to minimize photon noise. Coating the e2v CCD57-10 512x512 detectors with Lumogen-E coating allows for a relatively high (30 percent) quantum efficiency at the Lyman-alpha line. The CLASP cameras were designed to operate with a gain of 2.0 +/- 0.5, less than or equal to 25 e- readout noise, less than or equal to 10 e-/second/pixel dark current, and less than 0.1percent residual non-linearity. We present the results of the performance characterization study performed on the CLASP prototype camera; system gain, dark current, read noise, and residual non-linearity. |
| NASA分類 | Instrumentation and Photography |
| レポートNO | M14-3797 |
| 権利 | Copyright, Distribution as joint owner in the copyright |
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