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11 March 2003 Characteristics of the on-orbit background of the Chandra x-ray observatory high-resolution camera
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The Chandra X-ray Observatory (CXO) High Resolution Camera (HRC) is a microchannel plate (MCP) based X-ray detector with heritage from similar detectors flown on the Einstein and ROSAT missions. The HRC consists of two detectors in a common housing. Improvements from the previous instruments include: fabricating the MCP from 'low-noise' glass (glass that contains a reduced level of radioactive isotopes) and surrounding the detector housing on five sides with an active coincidence detector. Both of these improvements help to maximize the X-ray signal to background noise ratio. The on-orbit background is dominated by cosmic ray and solar-wind particles. The temporal behavior of the background has two parts: a quiescent level and a flaring component. The quiescent level slowly changes with time and is correlated with the high-energy particle flux as measured by the Electron Proton Helium Instrument (EPHIN), the CXO radiation detector. The flaring component is associated with times of elevated low-energy particle flux, primarily from the Sun. A combination of on-board vetoing and filtering during ground processing provides a substantial rejection of the non-X-ray background. This work was supported by NASA contract NAS8-39073 to the Chandra X-ray Center.
© (2003) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Michael Juda, R. Hank Donnelly, K. Tabetha Hole, Almus T. Kenter, Ralph Porter Kraft, Stephen S. Murray, Deron O. Pease, Charles R.A. Wilton, and Martin V. Zombeck "Characteristics of the on-orbit background of the Chandra x-ray observatory high-resolution camera", Proc. SPIE 4851, X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy, (11 March 2003);


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