GaAs detectors irradiated by electrons at different dose rates

Abstract

and the Slovak Academy of Sciences No. VEGA-2/0062/13 and No. VEGA-2/0175/13. MOTIVATION  Bulk Semi-Insulating (SI) GaAs: suitable material for preparation of high-energy charged particle detectors, gamma ray detectors as well as the neutron detectors.

The influence of high-energy electrons irradiation on the electrical properties of Schottky barrier detectors based on semi-insulating GaAs

“…A whole area Ni/AuGe/Au (30 nm/50 nm/90 nm) quasi-ohmic metal electrode was formed on the back side of the substrate. Each segment with four Schottky detector diodes was glued onto a separate holder and wire bonded to contacting pad [10]. Current-voltage measurements were carried out with each Schottky contact detector in the dark at temperature 298 K. Then the detectors were placed on a 1 cm thick Al board and irradiated from the Schottky contact side by a pulse beam (3.5 µs pulse duration) of 5 MeV electrons at room temperature using the linear accelerator UELR 5-1S.…”

Spectrometric properties of semi-insulating GaAs detectors irradiated by 5 MeV electrons at different dose rates

“…The decrease of CCE and relative energy resolution (FWHM) but an increase in detection efficiency were observed with increasing dose of 5 MeV electrons in the range of doses from 10 to 104 kGy. In the paper [6] the influence of various dose rates during irradiation of GaAs detectors by 5 MeV electrons on their spectrometric properties was studied. Here, the cumulative dose varied from 1 to 24 kGy.…”

“…Afanaciev et al in [4] irradiated the Cr-doped GaAs sensors by 10 and 8.5 MeV electron beam by a dose rate of 20 to 400 kGy/h to a total dose of 1.5 MGy and observed the charge collection efficiency (CCE) degradation with the absorbed dose. We have also studied the radiation hardness of GaAs detectors against high-energy electrons in our previous research [5][6][7][8]. In [5] we have noticed slight changes of the spectrometric properties at low doses (5 to 10 kGy) but the detector properties were rather poor, caused by the Schottky contact topology.…”

“…The future electron-positron collider planned in Europe [3] will be exposed to electron-positron pairs from bremsstrahlung of a dose of about 1 MGy per year. There are very few studies dealing with radiation resistance of GaAs detectors against high-energy electrons [4][5][6][7][8]. Afanaciev et al in [4] irradiated the Cr-doped GaAs sensors by 10 and 8.5 MeV electron beam by a dose rate of 20 to 400 kGy/h to a total dose of 1.5 MGy and observed the charge collection efficiency (CCE) degradation with the absorbed dose.…”

“…In [5] we have noticed slight changes of the spectrometric properties at low doses (5 to 10 kGy) but the detector properties were rather poor, caused by the Schottky contact topology. In [6][7][8] we have investigated the Schottky barrier SI GaAs detectors of better spectrometric quality, with defined position from GaAs wafer, and we obtained higher statistics by a larger group of detectors. The paper [7] studied the influence of 5 MeV electrons on electrical properties of our GaAs detectors up to a dose of 104 kGy obtained by three different dose rates.…”