Mitigating radiation-induced charge transfer inefficiency in full-frame CCD applications by 'pumping' traps
Mitigating radiation-induced charge transfer inefficiency in full-frame CCD applications by 'pumping' traps
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通过“泵浦”陷阱缓解全帧 CCD 应用中辐射引起的电荷转移效率低下
DOI：
10.1117/12.926804
复制
发表时间：
2012
影响因子：
3.1
通讯作者：
J. Endicott
中科院分区：
文献类型：
--
作者：
N. Murray;A. Holland;J. Gow;David J. Hall;J. Tutt;D. Burt;J. Endicott
CCD 的电荷传输效率基于多次传输期间每个像素丢失的信号的平均水平。该值可用于直接比较不同结构的相对性能、辐射损伤的增加或量化操作参数的改进。然而，这个数字并没有提供足够的细节来减轻任一传输方向上的实际信号丢失/偏差，这对于高精度测量形状可能至关重要，例如基于空间辐射环境的天文学应用（例如盖亚的天体测量或欧几里得的星系畸变测量）所需的那些。口袋泵是一种确定陷阱位置和激活水平的成熟技术。然而，还可以探索该过程中的许多参数来识别陷阱种类和亚像素精度的位置。该信息可以通过两种方式使用来提高相机的灵敏度。首先，可以针对每个传输方向上的大多数陷阱的时间常数来优化时钟过程，从而减少读出期间的延迟电荷。其次，可以在各个帧的后处理期间开发和采用校正算法，以将大部分延迟信号移回到其起源的电荷包中。在这里，我们介绍了用于优化 p 通道和 n 通道 e2v CCD204 电荷转移效率的陷阱泵浦技术，并描述了陷阱泵浦图像在在轨校准和地面图像校正算法中的使用。
The charge transfer efficiency of a CCD is based on the average level of signal lost per pixel over a number of transfers. This value can be used to directly compare the relative performances of different structures, increases in radiation damage or to quantify improvements in operating parameters. This number does not however give sufficient detail to mitigate for the actual signal loss/deference in either of the transfer directions that may be critical to measuring shapes to high accuracy, such as those required in astronomy applications (e.g. for Gaia’s astrometry or the galaxy distortion measurements for Euclid) based in the radiation environment of space. Pocket-pumping is an established technique for finding the location and activation levels of traps; however, a number of parameters in the process can also be explored to identify the trap species and location to sub-pixel accuracy. This information can be used in two ways to increase the sensitivity of a camera. Firstly, the clocking process can be optimised for the time constant of the majority of traps in each of the transfer directions, reducing deferred charge during read out. Secondly, a correction algorithm can be developed and employed during the post-processing of individual frames to move most of any deferred signal back into the charge packet it originated from. Here we present the trap-pumping techniques used to optimise the charge transfer efficiency of p- and n-channel e2v CCD204s and describe the use of trap-pumped images for on-orbit calibration and ground based image correction algorithms.
用于 ESA Euclid M 级任务的电荷耦合器件
DOI：
10.1117/12.926323
发表时间：
2012
期刊：
--
影响因子：
--
作者：
Endicott J
通讯作者：
Endicott J