Soft X-ray and EUV response of Superconducting Tunnel Junctions: strong deviations from linearity

被引：3

作者：

Poelaert, A ^{[1
]}

Kozorezov, A ^{[1
]}

Peacock, A ^{[1
]}

Wigmore, K ^{[1
]}

Verhoeve, P ^{[1
]}

van Dordrecht, A ^{[1
]}

Owens, A ^{[1
]}

Rando, N ^{[1
]}

机构：

[1] European Space Agcy, Estec, Div Astrophys, NL-2200 AG Noordwijk, Netherlands

来源：

EUV, X-RAY, AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY IX | 1998年 / 3445卷

关键词：

x-ray; superconductivity; linearity;

D O I：

10.1117/12.330279

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Nb-Al-AlOx-Al-Nb Superconducting Tunnel Junctions (STJ's) have been extensively investigated by a number of groups as potential next generation high resolution photon detectors for X-ray astronomy. The response of such devices has been studied from EW (40 eV) to soft X-rays (6 keV), using highly monochromatic synchrotron radiation. Based on the current understanding of the charge production and tunneling mechanism in STJ's, it would be expected that at lower energies, the responsivity of the detector would increase as the role of self-recombination of charge carriers into Cooper pairs declines in importance. Here responsivity is simply defined as the measured charge per eV of photon energy deposited in the junction. This trend however was not observed till the lowest energies. Below a threshold energy the responsivity fell, reaching a minimum level, after which it became constant. This minimum level is lower than the responsivity at 6 keV, by a factor up to 5, leading to a clear mismatch between X-ray and EUV performance. This paper summarizes the observations, and presents quantitative explanations for the feature, based on the existence of local traps in the STJ.

引用

页码：214 / 225

页数：12