DocumentCode :
1078543
Title :
High Count Rate Neutron Spectrometry With Liquid Scintillation Detectors
Author :
Marocco, Daniele ; Belli, Francesco ; Esposito, Basilio ; Riva, Marco ; Giacomelli, Luca ; Reginatto, Marcel ; Tittelmeier, Kai ; Zimbal, Andreas
Author_Institution :
Associazione Euratom-ENEA sulla Fusione, Frascati
Volume :
56
Issue :
3
fYear :
2009
fDate :
6/1/2009 12:00:00 AM
Firstpage :
1168
Lastpage :
1173
Abstract :
Liquid scintillation detectors are widely used in nuclear/high-energy physics and nuclear fusion for spectral measurements in mixed radiation fields due to their compactness, fast response and neutron/gamma discrimination capabilities. The use of response functions evaluated for the specific system and of appropriate methods of data analysis allows such systems to be used as broadband spectrometers for photons and neutrons. System stability and ability to reach high throughput count rates are key challenges for several applications (e.g., neutron spectrometry for nuclear fusion devices), but standard analog electronics limits the operation of liquid scintillation neutron spectrometers to low count rates ( ~ 3 ldr 104 s-1) . The count rate capabilities of a liquid scintillation neutron spectrometer (NE213 detector) from the Physikalisch-Technische Bundesanstalt (PTB) has been extended up to ~ 4.2 ldr 105 s-1, by coupling it to a digital acquisition system developed at ENEA-Frascati. Measurements have been carried out at PTB using gamma sources and accelerator-produced 2.5 MeV and 14 MeV neutrons. For 14 MeV neutron measurements, digital pulse height spectra (PHS) obtained at high count rates have been compared to PHS recorded with standard analog electronics. The results show that stable PHS (within 1%) can be obtained at high count rate despite the high sensitivity of the gain of photomultiplier tubes to count rate variations.
Keywords :
liquid scintillation detectors; neutron effects; neutron spectrometers; nuclear electronics; photomultipliers; radioactive sources; ENEA-Frascati; analog electronics; digital acquisition system; digital pulse height spectrum; electron volt energy 2.5 MeV to 14 MeV; gamma source; high count rate neutron spectrometry; liquid scintillation detector; liquid scintillation neutron spectrometer; neutron-gamma discrimination capability; nuclear fusion; nuclear fusion device; nuclear-high-energy physics; photomultiplier tube; photon spectrometer; radiation field; Data analysis; Fusion reactors; Neutrons; Nuclear measurements; Physics; Pulse measurements; Scintillation counters; Spectroscopy; Stability; Throughput; Digitizer; high count rate; neutron spectrometry;
fLanguage :
English
Journal_Title :
Nuclear Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9499
Type :
jour
DOI :
10.1109/TNS.2009.2020164
Filename :
5075971
Link To Document :
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