Evaluation of GAGG:Ce scintillators for future space applications

Abstract

Cerium-doped Gd3(Ga, Al)5O12 (GAGG:Ce) is a promising novel scintillator for gamma-ray detectors. While GAGG:Ce has already been implemented in various commercial products, its detailed characteristics and response to high-energy particles and gamma rays remain unknown. In particular, knowledge is lacking on the radiation tolerance of this scintillator against the gamma-ray and proton irradiation expected in future space satellite mission applications. In this study, we first investigate the light-yield energy dependence, energy resolution, decay time, radiation tolerance, and afterglow of GAGG:Ce scintillators under various temperature conditions. We find excellent linearity of ±3% between light yields and deposited energy over a wide range of 30–1836 keV; however, a light-yield deficit of more than 10% is observed below 30 keV of deposited gamma ray energy. We confirm that the temperature dependence of the light yield, energy resolution, and scintillation decay time is within 5–20% between −20 and 20 ̂C. We also evaluate the GAGG:Ce activation characteristics under proton irradiation and the light-yield degradation by accumulated dose using a 60Co source. Moreover, we successfully identify various gamma-ray lines due to activation. Finally, we find a substantial afterglow for GAGG:Ce scintillators over a few hours; such an afterglow is only minimally observed in other scintillators such as CsI:Tl and Bi4Ge3O12 (BGO). However, the afterglow can be substantially reduced through additional co-doping with divalent metal ions, such as Mg ions. These results suggest that GAGG:Ce is a promising scintillator with potential application in space satellite missions in the near future.

Gamma-Ray Sensor Using YAlO3(Ce) Single Crystal and CNT/PEEK with High Sensitivity and Stability under Harsh Underwater Conditions

“…As mentioned in Section 1 , we considered YAlO 3 (Ce) as a promising scintillation material [ 12 , 20 ], along with Gd 3 Al 2 Ga 3 O 12 (Ce), owing to the desirable features of non-hygroscopicity, mechanical hardness (none of the cleavage planes, scratch hardness ≥8.5 Mohs), short decay time (≤150 ns), and fair photoelectron yield and well-coordinated wavelength with the conventional photomultiplier tubes (PMTs). In particular, their relatively high radiation hardness is advantageous for precise and accurate gamma-ray measurements without any degradation under high background radiation conditions such as in medical and space applications [ 21 , 22 ]. Therefore, we considered both types of crystals as candidates for the gamma-ray sensing materials, and their performances were compared with those of the conventional NaI(Tl) scintillator of identical sizes.…”

A Compton polarimeter using scintillators read out with MPPCs through Citiroc ASIC

“…Compared to other inorganic scintillators, it has advantages like higher density, leading to high stopping power, and high light-yield. It is non-hygroscopic and its lightyield shows a 20% variation in the temperature range, between -20 − 20 • C [22]. As it is a recent development, its use in the space radiation environment is not fully explored [16,23].…”

Development and performance verification of a 3-D position-sensitive Compton camera for imaging MeV gamma rays

“…Although there are various choices of detectors as the scatterer and absorber 12–15 , our group adopted Ce-doped Ge 3 Al 2 Ga 3 O 12 (Ce:GAGG) scintillators for environmental survey and medical use 16,17 . The properties of Ce:GAGG scintillators, such as radiation tolerance, have already investigated in a study that confirmed the suitability of Ce:GAGG for use in space satellite missions 18 . The high density of Ce:GAGG, combined with a compact configuration of the camera, can realize a high intrinsic efficiency, but in general, a scatterer has to be set considerably apart from an absorber to achieve a high angular resolution.…”