InGaP electron spectrometer for high temperature environments

Abstract

In this work, a 200 μm diameter InGaP (GaInP) p + -i-n + mesa photodiode was studied across the temperature range 100 °C to 20 °C for the development of a temperature-tolerant electron spectrometer. The depletion layer thickness of the InGaP device was 5 μm. The performance of the InGaP detector was analysed under dark conditions and then under the illumination of a 183 MBq 63 Ni radioisotope beta particle source. The InGaP photodiode was connected to a custom-made low-noise charge-sensitive preamplifier to realise a particle counting electron spectrometer. Beta spectra were collected at temperatures up to 100 °C with the InGaP device reverse biased at 5 V. The spectrum accumulated at 20 °C was compared with the spectrum predicted using Monte Carlo simulations; good agreement was found between the predicted and experimental spectra. The work is of importance for the development of electron spectrometers that can be used for planetary and space science missions to environments of high temperature or extreme radiation (e.g. Mercury, Jupiter’s moon Europa, near-Sun comets), as well as terrestrial applications.

Electron spectroscopy with a diamond detector

“…However, the e ciency of the GaAs detector declined to 0.49 at 100 keV (100 keV β − particles were less likely to fully deposit their energy in the active i layer). Other reported emergent semiconductor detectors considered suitable for deep space electron spectrometry are InGaP 17 and AlGaAs 16 . The active i layers for both reported detectors were thin; 5 µm for InGaP and 3 µm for AlGaAs, consequently and despite the superior stopping power of the materials used in the detectors, the β − particle detection e ciencies were lower than for the presently reported diamond detector.…”

“…Wide bandgap solid state detectors may provide such bene ts. Wide bandgap radiation detectors that have been proposed for spectroscopic electron detection for space applications include GaAs 1213 , SiC 14 , AlGaAs 1516 , and InGaP 17 . Each offers particular advantages and trade-offs in terms of radiation hardness, temperature tolerance, and electron detection e ciency.…”

AlGaAs two by two pixel detector for electron spectroscopy in space environments

“…Secondary electron generation was not included in the simulations. The same CASINO settings and presently reported methodology were used in refs [35], [36], and [37], to simulate similar situations in GaAs, SiC, and InGaP electron detectors. Fig.…”

“…A bank of 14 computers, each with an Intel i7-6700 (4 cores, 3.40 GHz) processor and 32 GB of random access memory, was used to perform the simulations. The presently reported methodology was the same as that used in refs [35], [36], and [37].…”