Speaker
Description
Space telescopes of charged particles consist of stack of Si detectors and are intended for measurements of energy and direction of motion the particles. The detectors are as Si slabs supplied by permanent bias voltage [1]. We proposed [2] application of Si detectors with smoothly varying by the bias voltage thickness of the depleted zone in the telescope. The application of such detectors would allow optimize operation of the space telescope without any mechanical motions.
For instance, 1.6 mm thick beryllium slab is installed before the first detector of the telescope for absorption of low-energy particles [1]. The slab provides fixed energy threshold for incident particles. Instead of beryllium slab, we propose to install the first Si detector with depleted zone turned toward the telescope. Regulating bias voltage, one can simultaneously change the thickness of the depleted zone and the thickness of non-sensitive Si layer, where charge is not collected from. Thus, one can smoothly regulate the thickness of absorbing layer and register passed particles in depleted zone of the same first detector. This means that the energy threshold at observation of charged particles can be variated smoothly, that is impossible with the beryllium slab.
Si detectors with variable thicknesses were studied in our researches with electrons of energy < 1 MeV in KIPT [3] and 50 GeV protons at accelerator U-70 [4].
References
[1] D.N. Baker et al. Space Science Reviews 179 (2017) 337–381.
[2] A.V. Shchagin. Semiconductor detectors with smoothly tunable thickness in space relativistic electron-proton telescope. Theses of reports at XVII conference on high energy physics and nuclear physics, 26-29 March 2019, KIPT, Kharkov, Ukraine, p. 103-104. The thesis is available in English in page 103 at:
https://www.kipt.kharkov.ua/conferences/ihepnp/2019/collection_of_theses_%D0%A5VII_hepnp.pdf
[3] A.V. Shchagin, N.F. Shul’ga, S.V. Trofymenko, R.M. Nazhmudinov, A.S. Kubankin. Semiconductor detector with smoothly tunable effective thickness for the study of ionization loss by moderately relativistic electrons. Nucl. Instrum. Methods B 387 (2016) 29–33.
[4] R.M. Nazhmudinov, A.S. Kubankin, A.V. Shchagin, N.F. Shul’ga, S.V. Trofymenko, G.I. Britvich, A.A. Durum, M.Yu. Kostin, V.A. Maisheev, Yu.A. Chesnokov, A.A. Yanovich. Study of 50 GeV proton ionization loss by semiconductor detector with smoothly tunable thickness. Nucl. Instrum. Methods B 391 (2017) 69–72.
