The quasiparticle lifetimes and tunneltimes in SIS tunnel junctions are essential parameters in the development of these devices for high resolution X-ray spectroscopy. We present a simple analytical model which allows us to calculate both the risetime and the total charge of the integrated tunnel current following an X-ray event. Simultaneous measurement of both the total charge and the risetime thus becomes a useful diagnostic tool for quantitative analysis. We have applied the model to recent X-ray measurements on a Nb/AlOx SIS junction. We find that the energy resolution achieved in this device is mainly limited by variations in the thickness of the counter electrode.
|Journal||Nuclear instruments & methods in physics research. Section A : Accelerators, spectrometers, detectors and associated equipment|
|Publication status||Published - 1996|
Luiten, O. J., van Lieshout, H. L., Michels, F. A., Valko, P., Bruijn, M. P., Kiewiet, F., ... Flokstra, J. (1996). Quasiparticle lifetimes and tunneltimes in SIS junctions for X-ray spectroscopy. Nuclear instruments & methods in physics research. Section A : Accelerators, spectrometers, detectors and associated equipment, 370(1), 72-74. https://doi.org/10.1016/0168-9002(95)01052-1