A study of electron-multiplying CCDs for use on the International X-ray Observatory off-plane x-ray grating spectrometer
A study of electron-multiplying CCDs for use on the International X-ray Observatory off-plane x-ray grating spectrometer
复制标题
国际X射线天文台离面X射线光栅光谱仪用电子倍增CCD的研究
DOI：
10.1117/12.861626
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
M. Robbins
中科院分区：
文献类型：
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作者：
J. Tutt;A. Holland;N. Murray;D. Hall;R. McEntaffer;J. Endicott;M. Robbins
由于其在整个能量范围内的高量子效率和线性，ccd经常被用作空间望远镜在x射线能量下的成像和光谱设备。国际x射线天文台的x射线光栅光谱仪也将在0.3 keV到1 keV的能量带上使用这些设备。在这些能量下，当光子计数时，硅中产生的电荷接近系统的噪声。为了能够探测到这些低能量的x射线事件，探测器的系统噪声必须最小化，以具有足够的信噪比。通过使用EM-CCD而不是传统的CCD，设备中收集的任何电荷都可以在读出之前乘以，只要EM-CCD足够凉爽以充分抑制暗电流，设备的信噪比就可以显着增加，从而使软x射线事件更容易被检测到。本文将研究em - ccd用于检测低能x射线，特别是使用这些设备将对信噪比的影响，以及由于电荷包放大过程引起的信号上的额外散粒噪声可能导致的分辨率和FWHM的任何退化。
CCDs are regularly used as imaging and spectroscopic devices on space telescopes at X-ray energies due to their high quantum efficiency and linearity across the energy range. The International X-ray Observatory's X-ray Grating Spectrometer will also look to make use of these devices across the energy band of 0.3 keV to 1 keV. At these energies, when photon counting, the charge generated in the silicon is close to the noise of the system. In order to be able to detect these low energy X-ray events, the system noise of the detector has to be minimised to have a sufficient signal-to-noise-ratio. By using an EM-CCD instead of a conventional CCD, any charge that is collected in the device can be multiplied before it is read out and as long as the EM-CCD is cool enough to adequately suppress the dark current, the signal-to-noise ratio of the device can be significantly increased, allowing soft X-ray events to be more easily detected. This paper will look into the use of EM-CCDs for the detection of low energy X-rays, in particular the effect that using these devices will have on the signal to noise ratio as well as any degradation in resolution and FWHM that may occur due to the additional shot noise on the signal caused by the charge packet amplification process.