A fast model of radiation-induced electron trapping in CCDs for implementation in the Gaia data processing
A fast model of radiation-induced electron trapping in CCDs for implementation in the Gaia data processing
复制标题
用于盖亚数据处理的 CCD 中辐射诱导电子捕获的快速模型
DOI：
10.1117/12.856386
复制
发表时间：
2010
影响因子：
1.3
通讯作者：
Anthony G. A. Brown
中科院分区：
文献类型：
--
作者：
A. Short;T. Prod’homme;M. Weiler;Scott Brown;Anthony G. A. Brown
欧洲航天局的盖亚任务计划于2012年发射。它将在L2运行5年，缓慢旋转，使其两个光学望远镜可以重复观测超过10亿颗恒星。得到的数据集将被迭代缩减，以求出每一颗观测到的恒星的相对位置、视差距离和自行，从而得到我们银河系的三维动力学模型。焦平面包含106个大面积硅ccd，以与卫星自转同步的线速以TDI模式连续运行。2此次飞行任务面临的最大挑战之一是ccd的辐射损伤，这将导致电荷损失和图像失真。这一情况尤其严重，因为大焦面很难遮挡，而且发射将与太阳最高值重合。尽管采取了将辐射影响降至最低的步骤(例如，定期使用电荷注入)，但需要在管道数据处理过程中校准残余失真。由于涉及的数据量很大，这需要一个物理上真实的陷阱模型，但又足够快和足够简单，可以在管道中实现。将介绍当前的原型电荷变形模型。该模型是专门为TDI模式下的Gaia开发的。然而，成像模式版本已经应用于其他飞行任务，例如，以显示辐射损害对拟议的欧几里德飞行任务的潜在影响。
The European Space Agency's Gaia mission1 is scheduled for launch in 2012. It will operate at L2 for 5 years, rotating slowly so that its two optical telescopes will repeatedly observe more than one billion stars. The resulting data set will be iteratively reduced to solve for the relative position, parallax-distance and proper motion of every observed star, yielding a three dimensional dynamical model of our galaxy. The focal plane contains 106 large area silicon CCDs continuously operating in TDI mode at a line rate synchronised with the satellite rotation.2 One of the greatest challenges facing the mission is radiation damage in the CCDs which will cause charge loss and image distortion. This is particularly severe because the large focal plane is difficult to shield and because the launch will coincide with solar maximum. Despite steps taken to minimize the effects of radiation (e.g. regular use of charge injection), the residual distortion will need to be calibrated during the pipeline data processing. Due to the volume of data involved, this requires a trapping model which is physically realistic, yet fast enough and simple enough to implement in the pipeline. The current prototype Charge Distortion Model will be presented. This model was developed specifically for Gaia in TDI mode. However, an imaging mode version has already been applied to other missions, for example, to indicate the potential impact of radiation damage on the proposed Euclid mission.