An imaging technique for detection and absolute calibration of scintillation light (original) (raw)
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Performance of a Facility for Measuring Scintillator Non-Proportionality
IEEE Transactions on Nuclear Science, 2008
We have constructed a second-generation Compton coincidence instrument, known as the Scintillator Light Yield Non-proportionality Characterization Instrument (SLYNCI), to characterize the electron response of scintillating materials. While the SLYNCI design includes more and higher efficiency HPGe detectors than the original apparatus (five 25%-30% detectors vs. one 10% detector), the most novel feature is that no collimator is placed in front of the HPGe detectors. Because of these improvements, the SLYNCI data collection rate is over 30 times higher than the original instrument. In this paper, we present a validation study of this instrument, reporting on the hardware implementation, calibration, and performance. We discuss the analysis method and present measurements of the electron response of NaI:Tl from two different samples. We also discuss the systematic errors of the measurement, especially those that are unique to SLYNCI. We find that the apparatus is very stable, but that careful attention must be paid to the energy calibration of the HPGe detectors.
Outlook for development of a scintielectron detector with improved energy resolution
2002
The development prospects have been considered of a scintillator-photodiode type detector with improved energy resolution attaining several per cent ($R=1-2%$). The main contributions to the scintielectron detector energy resolution have been analyzed theoretically and their theoretical and physical limits determined. Experimental data have been presented on properties of scintillators of promise confirming the possibilities to minimize each of the resolution components. New ways are proposed to optimize the detector statistical contribution and the scintillator intrinsic resolution. A special role of the latter is outlined as the critical factor for the spectrometric possibilities (threshold) of scintillation-photodiode type detector with improved energy resolution at energy values EgammaE_{\gamma}Egamma from 662keV662 keV662keV to 10MeV10 MeV10MeV.
Fast digitizing techniques applied to scintillation detectors
Nuclear Physics B - Proceedings Supplements, 2006
A 200 MHz 12-bit fast transient recorder card has been used for the digitization of pulses from photomultipliers coupled to organic scintillation detectors. Two modes of operation have been developed at ENEA-Frascati: a) continuous acquisition up to a maximum duration of ∼ 1.3 s corresponding to the full on-board memory (256 MSamples) of the card: in this mode, all scintillation events are recorded; b) non-continuous acquisition in which digitization is triggered by those scintillaton events whose amplitude is above a threshold value: the digitizing interval after each trigger can be set according to the typical decay time of the scintillation events; longer acquisition durations (>1.3 s) can be reached, although with dead time (needed for data storage) which depends on the incoming event rate. Several important features are provided by this novel digital approach: high count rate operation, pulse shape analysis, post-experiment data re-processing, pile-up identification and treatment. In particular, NE213 scintillators have been successfully used with this system for measurements in mixed neutron (n) and gamma (γ) radiation fields from fusion plasmas: separation between γ and neutron events is made by means of a dedicated software comparing the pulse charge integrated in two different time intervals and simultaneous neutron and γ pulse height spectra can be recorded at total count rates in the MHz range. It has been demonstrated that, for scintillation detection applications, 12-bit fast transient recorder cards offer improved performance with respect to analogue hardware; other radiation detectors where pulse identification or high count rate is required might also benefit from such digitizing techniques.
Review of Scientific Instruments, 2010
In order to investigate the limits of scintillating screens for beam profile monitoring in the ultra-low energy, ultra-low intensity regime, CsI:Tl, YAG:Ce, and a Tb glass-based scintillating fiber optic plate ͑SFOP͒ were tested. The screens response to 200 and 50 keV proton beams with intensities ranging from a few picoampere down to the subfemtoampere region was examined. In the following paper, the sensitivity and resolution studies are presented in detail for CsI:Tl and the SFOP, the two most sensitive screens. In addition, a possible use of scintillators for ultra-low energy antiproton beam monitoring is discussed.
Nukleonika
LaBr 3 :Ce,CeBr 3 and GAGG:Ce scintillators were investigated and the determined characteristics were compared with those obtained for the well-known and widely used CsI:Tl and NaI:Tl crystals. All the detectors were of the same size of 10 × 10 × 5 mm 3. The aim of this test study was to single out scintillation detectors most suitable for -ray spectrometry and -ray emission radial profi le measurements in high-temperature plasma experiments. Decay time, energy resolution, non-proportionality and full energy peak detection effi ciency were measured for -ray energies up to 1770 keV. Due to their good energy resolution, short decay time and high detection effi ciency for MeV gamma rays, LaBr 3 :Ce and CeBr 3 scintillators are proposed as the best candidates for use especially under conditions of high count rates, which are expected in the forthcoming DT experiments.
Photodetectors for scintillator proportionality measurement
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009
We evaluate photodetectors for use in a Compton Coincidence apparatus designed for measuring scintillator proportionality. There are many requirements placed on the photodetector in these systems, including active area, linearity, and the ability to accurately measure low light levels (which implies high quantum efficiency and high signal-to-noise ratio). Through a combination of measurement and Monte Carlo simulation, we evaluate a number of potential photodetectors, especially photomultiplier Page 2 tubes and hybrid photodetectors. Of these, we find that the most promising devices available are photomultiplier tubes with high (~50%) quantum efficiency, although hybrid photodetectors with high quantum efficiency would be preferable.
Energy resolution and energy–light response of CsI(Tl) scintillators for charged particle detection
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2001
This article describes the crystal selection and quality control utilized to develop and calibrate a high-resolution array of CsI(Tl) scintillator crystals for the detection of energetic charged particles. Alpha sources are used to test the light output variation due to thallium doping gradients. Selection of crystals with better than 1% non-uniformity in light output is accomplished using this method. Tests with a 240 MeV alpha beam reveal that local light output variations within each of the tested CsI(Tl) crystals limit the resolution to about 0.5%. Charge and mass dependences in the energy}light output relationship are determined by calibrating with energetic projectile fragmentation beams.