Cryogenic irradiations, a more realistic study of the impact of radiation on detectors in space

低温辐射，对辐射对太空探测器影响的更现实的研究

基本信息

批准号：
1810175
负责人：
金额：
--
依托单位：
The Open University
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2016
资助国家：
英国
起止时间：
2016 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=studentship-1810175
关键词：
Cryogenic irradiations more realistic study

项目摘要

Charge-Coupled Devices (CCDs) have long been the detectors of choice for space astronomy missions. When placed in orbit, the devices can experience a harsh radiation environment. The radiation incident on the detector will act to damage the silicon lattice, creating defects that lead to the formation of "traps". The traps formed can capture signal that is being detected out of the device, leading to smearing and signal loss in CCDs and charge loss and bright pixels in CMOS sensors as well increasing sources of noise such as dark current.Before any mission is launched, it is vital that the impact of radiation is studied in detail such that appropriate shielding is used along with the development of novel readout techniques and correction algorithms to mitigate the damage that remains. Currently, standard practice dictates that radiation testing of devices is carried out at room temperature, despite the fact that the detectors will be kept cold during operation in orbit, with temperatures often as low as -120 degrees Celsius.The vacancies created after irradiation migrate through the device until they reach a stable state, but the stability of any particular defect structure is strongly dependent on temperature; the traps present at room temperature may be dramatically different to those present when a device is irradiated cold and kept cold. Literature on the so called "cryogenic irradiation" is sparse, but there are reports of a factor of 2-3 difference between the impact of radiation at room temperature compared to the more realistic cryogenic irradiation, with the direction of this difference (increased or decreased impact) varying between different device types.ESA's Euclid mission, aiming to map dark matter and energy, is dependent on a complete and thorough understanding of the impact of radiation on the detectors to allow for correction against radiation to reduce the smearing by up to 300 times. Hubble is able to correct by approximately a factor of 30, one order of magnitude less than that required for Euclid's high precision measurements. ESA's JUICE mission will require a full understanding of the impact on CMOS sensors of the harsh electron-dominated radiation environment near Jupiter and the large CCD's baselined for ESA's Plato mission will lead to the transfer of signal charge across large areas of radiation damaged silicon.Cryogenic irradiations present many challenges as the devices must be kept cold (and therefore under vacuum) at all times, including whilst irradiating and for a period of weeks or months after the irradiation. Equipment and techniques have been developed within the Centre for Electronic Imaging (CEI) over the past 12 months that have allowed our first cryogenic irradiations to take place. Early results demonstrate that there is a dramatic difference between the cryogenic results and those performed at room temperature, including the presence of different trap species and densities of populations.

充电耦合设备（CCD）长期以来一直是太空天文任务的首选探测器。当放置在轨道上时，设备可以体验到刺激性的辐射环境。探测器上的辐射将起作用来损坏硅晶格，从而产生导致“陷阱”形成的缺陷。 The traps formed can capture signal that is being detected out of the device, leading to smearing and signal loss in CCDs and charge loss and bright pixels in CMOS sensors as well increasing sources of noise such as dark current.Before any mission is launched, it is vital that the impact of radiation is studied in detail such that appropriate shielding is used along with the development of novel readout techniques and correction algorithms to mitigate the damage that remains.目前，标准实践表明，设备的辐射测试是在室温下进行的，尽管在轨道操作过程中探测器会保持冷，温度通常低至-120度摄氏度。辐射后创建的空缺通过设备迁移，直到达到稳定的状态，但是任何特定的缺陷结构的稳定性是强大的依赖性依赖于温度的特定缺陷的稳定性；室温下存在的陷阱可能与当设备被辐照冷并保持冷时存在截然不同的陷阱。关于所谓的“低温照射”的文献很少，但是与更逼真的低温照射相比，室温下辐射的影响之间有2-3倍的差异，而这种差异的方向（增加或减少了影响）（增加或减少的影响）在不同的设备类型之间变化。ESA的euclid Mission允许对黑暗物质和彻底理解完整的影响，旨在绘制黑暗物质和彻底的影响。辐射可将涂抹涂抹最多减少300次。哈勃能够校正大约30倍，比欧几里得高精度测量所需的数量级要小。 ESA的果汁任务将需要充分了解木星附近苛刻的电子主导的辐射环境的影响，并且大型CCD用于ESA柏拉图的任务将导致信号电荷在辐射损坏的大面积损坏的硅质上转移信号。辐照后数周或几个月。在过去的12个月中，在电子成像中心（CEI）中已经开发了设备和技术，这使我们的首次低温照射得以进行。早期结果表明，低温结果与在室温下进行的结果之间存在巨大差异，包括存在不同的陷阱物种和人群的密度。