Effectiveness of a dual solenoid magnetic shield at reducing x-ray-like background in silicon-based x-ray detectors
Effectiveness of a dual solenoid magnetic shield at reducing x-ray-like background in silicon-based x-ray detectors
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双螺线管磁屏蔽在减少硅基 X 射线探测器中类 X 射线背景方面的有效性
DOI：
10.1117/1.jatis.9.2.024008
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Davis C
中科院分区：
文献类型：
--
作者：
Davis C
在过去和现在的X射线天文飞行任务中，磁屏蔽被用来屏蔽探测器，使其不受通过望远镜光学装置进入的电子的影响，未来的飞行任务也计划使用软质子偏转器。然而，在过去十年中进行的模拟发现，很大一部分类X射线背景来自航天器屏蔽周围X射线探测器产生的次级电子，这些次级电子从各个方向各向同性地撞击探测器。在这里，给出了基于雅典娜广域成像仪初步设计结构的Geant4模拟结果，该模拟结果基于雅典娜广域成像仪的初步设计结构，对一个450 μm厚的探测器周围的简单双螺线管磁场进行了模拟。我们发现，对于等于或大于∼12 mT的两个线圈中间的磁场强度，双螺线管磁场对于防止由星系宇宙质子诱导的2-7keV之间的二次电子沉积到达探测器是非常有效的。虽然背景减少的确切程度将取决于具体的航天器和探测器设计，但这种磁屏蔽方法可以消除几乎所有与后向散射和吸收电子有关的背景，预计这将约占数百微米厚度的硅基X射线探测器预期离轴背景的三分之二，对于更薄的探测器可能更加有效，因为在这种探测器中，类X射线背景更多地由电子主导。这样做所需的磁场结构可以使用一组螺线管或钕磁体来产生，前提是功率需求能够得到充分的优化，或者钕的荧光线可以分别得到充分的衰减。还必须进行测试，以确保使用它的探测器具有足够的磁性；在此背景下，雅典娜广域成像仪周围的磁场强度当前限制为1 Mt，尽管另一种天基X射线探测器CCD97的磁性至少在6.4 Mt以上。
Magnetic shielding has been used during past and current x-ray astronomy missions to shield detectors from electrons entering through telescope optics, and soft proton diverters have also been planned for future missions. However, simulations performed throughout the past decade have discovered that a significant proportion of x-ray-like background originates from secondary electrons produced in spacecraft shielding surrounding x-ray detectors, which hit detectors isotropically from all directions. Here, the results from Geant4 simulations of a simple dual solenoid magnetic field surrounding a 450 μm thick detector with several on-chip layers based on the structure of preliminary designs for the ATHENA Wide Field Imager are presented. We found that for a magnetic field strength at the middle between the two coils of equal to or greater than ∼12 mT, a dual solenoid magnetic field is extremely effective at preventing secondary electrons depositing between 2 and 7 keV and induced by galactic cosmic protons from reaching the detector. While the exact level of background reduction would depend on specific spacecraft and detector design, this magnetic shielding method could remove almost all background associated with backscattering and absorbed electrons, which are expected to account for approximately two thirds of the expected off-axis background in silicon-based x-ray detectors of several hundred microns in thickness and would likely be even more effective for thinner detectors where x-ray-like background is even more dominated by electrons. The magnetic field structure necessary for doing this could be produced using a set of solenoids or neodymium magnets providing that power requirements can be sufficiently optimized or neodymium fluorescence lines can be sufficiently attenuated, respectively. Testing would also have to be done to ensure that detectors it is used on are sufficiently magnetically hard; for context, the current limit for magnetic field strength around the ATHENA Wide Field Imager is 1 mT although CCD97s, another type of space-based x-ray detector, are magnetically hard at least above 6.4 mT.
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DOI：
10.3847/1538-4357/ab698a
发表时间：
2019-08
期刊：
The Astrophysical Journal
影响因子：
--
作者：
E. Bulbul;R. Kraft;P. Nulsen;M. Freyberg;E. Miller;C. Grant;M. Bautz;D. Burrows;S. Allen;Tanja Eraerds;V. Fioretti;F. Gastaldello;V. Ghirardini;D. Hall;N. Meidinger;S. Molendi;A. Rau;D. Wilkins;J. Wilms
通讯作者：
E. Bulbul;R. Kraft;P. Nulsen;M. Freyberg;E. Miller;C. Grant;M. Bautz;D. Burrows;S. Allen;Tanja Eraerds;V. Fioretti;F. Gastaldello;V. Ghirardini;D. Hall;N. Meidinger;S. Molendi;A. Rau;D. Wilkins;J. Wilms
DOI：
10.1117/1.jatis.8.1.018001
发表时间：
2022-01
期刊：
Journal of Astronomical Telescopes, Instruments, and Systems
影响因子：
--
作者：
E. Miller;C. Grant;M. Bautz;S. Molendi;R. Kraft;P. Nulsen;E. Bulbul;S. Allen;D. Burrows;Tanja Eraerds;V. Fioretti;F. Gastaldello;D. Hall;M. Hubbard;J. Keelan;N. Meidinger;E. Perinati;A. Rau;D. Wilkins
通讯作者：
E. Miller;C. Grant;M. Bautz;S. Molendi;R. Kraft;P. Nulsen;E. Bulbul;S. Allen;D. Burrows;Tanja Eraerds;V. Fioretti;F. Gastaldello;D. Hall;M. Hubbard;J. Keelan;N. Meidinger;E. Perinati;A. Rau;D. Wilkins
近地轨道辐射环境及其对硬X射线聚焦望远镜瞬发背景的影响
影响因子：
4.8
作者：
V. Fioretti;A. Bulgarelli;G. Malaguti;V. Bianchin;M. Trifoglio;F. Gianotti
通讯作者：
F. Gianotti
雅典娜X射线太空望远镜超导磁偏转器的研究
影响因子：
1.8
作者：
N. Riva;V. Calvelli;R. Musenich;S. Farinon;S. Lotti;P. Saracco
通讯作者：
P. Saracco
磁体架构和主动辐射屏蔽研究 (MAARSS)
DOI：
--
发表时间：
2019
期刊：
影响因子：
--
作者：
S. Westover;R. Meinke;Shaun M. Nerolich;S. Washburn;R. Battison;W. Burger;Dallas Kasaboski;F. Davies
通讯作者：
F. Davies