کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8166170 1526228 2018 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Energy resolution experiments of conical organic scintillators and a comparison with Geant4 simulations
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم ابزار دقیق
پیش نمایش صفحه اول مقاله
Energy resolution experiments of conical organic scintillators and a comparison with Geant4 simulations
چکیده انگلیسی
An increase in light-collection efficiency (LCE) improves the energy resolution of scintillator-based detection systems. An improvement in energy resolution can benefit detector performance, for example by lowering the measurement threshold and achieving greater accuracy in light-output calibration. This work shows that LCE can be increased by modifying the scintillator shape to reduce optical-photon reflections, thereby decreasing transmission and absorption likelihood at the reflector boundary. The energy resolution of four organic scintillators (EJ200) were compared: two cones and two right-circular cylinders, all with equal base diameter and height (50 mm). The sides of each shape had two surface conditions: one was polished and the other was ground. Each scintillator was coupled to the center of four photomultiplier tube (PMT) configurations of different diameters. The photocathode response of all PMTs was assessed as a function of position using a small cube (5 mm height) of EJ200. The worst configuration, a highly polished conical scintillator mated to a PMT of equal base diameter, produced a smeared energy spectrum. The cause of spectrum smearing is explored in detail. Results demonstrate that a ground cone had the greatest improvement in energy resolution over a ground cylinder by approximately 16.2% at 478 keVee, when using the largest diameter (127 mm) PMT. This result is attributed to the greater LCE of the cone, its ground surface, and the uniform photocathode response near center of the largest PMT. Optical-photon transport simulations in Geant4 of the cone and cylinder assuming a diffuse reflector and a uniform photocathode were compared to the best experimental configuration and agreed well. If a detector application requires excellent energy resolution above all other considerations, a ground cone on a large PMT is recommended over a cylinder.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment - Volume 898, 1 August 2018, Pages 77-84
نویسندگان
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