INVESTIGATION OF NUCLEAR EMULSIONS IN TERMS OF NEUTRON DOSIMETRY

Abstract Neutron detection using nuclear emulsions can offer an alternative in personal dosimetry. The production of emulsions and their quality have to be well controlled with respect to their application in dosimetry. Nuclear emulsions consist mainly of gelatin and silver halide. Gelatin contains a significant amount of hydrogen, which can be used for fast neutron detection. The addition of B-10 in the emulsion is convenient for thermal neutron detection. In this paper, standard nuclear emulsions BR-2 and nuclear emulsions BR-2 enriched with boron produced at the Slavich Company, Russia, were applied for evaluation of fast and thermal neutron fluences. The results were obtained by calculation from the presumed emulsion composition without prior calibration. Evidence that nuclear emulsions used in the experiment are suitable for neutron dosimetry is provided.

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THE USE OF FAST NEUTRON DETECTION FOR MATERIALS ACCOUNTABILITY

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194514601409 ◽

2014 ◽

Vol 27 ◽

pp. 1460140 ◽

Cited By ~ 3

Author(s):

L. F. NAKAE ◽

G. F. CHAPLINE ◽

A. M. GLENN ◽

P. L. KERR ◽

K. S. KIM ◽

...

Keyword(s):

Thermal Neutron ◽

Fast Neutron ◽

Liquid Scintillator ◽

Neutron Detection ◽

Nuclear Material ◽

Detector Response ◽

Surprising Result ◽

Neutron Detectors ◽

Detection Techniques ◽

Fast Neutron Detection

For many years at LLNL, we have been developing time-correlated neutron detection techniques and algorithms for applications such as Arms Control, Threat Detection and Nuclear Material Assay. Many of our techniques have been developed specifically for the relatively low efficiency (a few percent) inherent in man-portable systems. Historically, thermal neutron detectors (mainly 3 He ) were used, taking advantage of the high thermal neutron interaction cross-sections, but more recently we have been investigating the use of fast neutron detection with liquid scintillators, inorganic crystals, and in the near future, pulse-shape discriminating plastics that respond over 1000 times faster (nanoseconds versus tens of microseconds) than thermal neutron detectors. Fast neutron detection offers considerable advantages, since the inherent nanosecond production timescales of fission and neutron-induced fission are preserved and measured instead of being lost in the thermalization of thermal neutron detectors. We are now applying fast neutron technology to the safeguards regime in the form of high efficiency counters. Faster detector response times and sensitivity to neutron momentum show promise in measuring, differentiating, and assaying samples that have modest to very high count rates, as well as mixed neutron sources (e.g., Pu oxide or Mixed Cm and Pu ). Here we report on measured results with our existing liquid scintillator array and promote the design of a nuclear material assay system that incorporates fast neutron detection, including the surprising result that fast liquid scintillator becomes competitive and even surpasses the precision of 3 He counters measuring correlated pairs in modest (kg) samples of plutonium.

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Fast neutron detection with Al2O3 thermoluminescence dosimeter

Nuclear Instruments and Methods in Physics Research ◽

10.1016/0167-5087(83)90719-6 ◽

1983 ◽

Vol 212 (1-3) ◽

pp. 383-386 ◽

Cited By ~ 6

Author(s):

Maria Ranogajec-Komor ◽

Margit Osvay ◽

Igor Dvornik ◽

Tamàs Biró

Keyword(s):

Fast Neutron ◽

Neutron Detection ◽

Thermoluminescence Dosimeter ◽

Fast Neutron Detection

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Organic semiconductors for fast-neutron detection

2011 IEEE Nuclear Science Symposium Conference Record ◽

10.1109/nssmic.2011.6154732 ◽

2011 ◽

Cited By ~ 1

Author(s):

Alireza Kargar ◽

Edgar V. Van Loef ◽

Leonard Cirignano ◽

Kanai S. Shah

Keyword(s):

Fast Neutron ◽

Organic Semiconductors ◽

Neutron Detection ◽

Fast Neutron Detection

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Advanced Multilayer Composite Heavy-Oxide Scintillator Detectors for High Efficiency Fast Neutron Detection

EPJ Web of Conferences ◽

10.1051/epjconf/201817007010 ◽

2018 ◽

Vol 170 ◽

pp. 07010 ◽

Cited By ~ 1

Author(s):

Vladimir D. Ryzhikov ◽

Sergei V. Naydenov ◽

Thierry Pochet ◽

Gennadiy M. Onyshchenko ◽

Leonid A. Piven ◽

...

Keyword(s):

Fast Neutron ◽

Count Rate ◽

High Efficiency ◽

Low Cost ◽

Neutron Detection ◽

Multilayer Composite ◽

Large Area ◽

Transparent Plastic ◽

Fast Neutron Detection ◽

Scintillator Detectors

We have developed and evaluated a new approach to fast neutron and neutron-gamma detection based on large-area multilayer composite heterogeneous detection media consisting of dispersed granules of small-crystalline scintillators contained in a transparent organic (plastic) matrix. Layers of the composite material are alternated with layers of transparent plastic scintillator material serving as light guides. The resulting detection medium – designated as ZEBRA – serves as both an active neutron converter and a detection scintillator which is designed to detect both neutrons and gamma-quanta. The composite layers of the ZEBRA detector consist of small heavy-oxide scintillators in the form of granules of crystalline BGO, GSO, ZWO, PWO and other materials. We have produced and tested the ZEBRA detector of sizes 100x100x41 mm and greater, and determined that they have very high efficiency of fast neutron detection (up to 49% or greater), comparable to that which can be achieved by large sized heavy-oxide single crystals of about Ø40x80 cm3 volume. We have also studied the sensitivity variation to fast neutron detection by using different types of multilayer ZEBRA detectors of 100 cm2 surface area and 41 mm thickness (with a detector weight of about 1 kg) and found it to be comparable to the sensitivity of a 3He-detector representing a total cross-section of about 2000 cm2 (with a weight of detector, including its plastic moderator, of about 120 kg). The measured count rate in response to a fast neutron source of 252Cf at 2 m for the ZEBRA-GSO detector of size 100x100x41 mm3 was 2.84 cps/ng, and this count rate can be doubled by increasing the detector height (and area) up to 200x100 mm2. In summary, the ZEBRA detectors represent a new type of high efficiency and low cost solid-state neutron detector that can be used for stationary neutron/gamma portals. They may represent an interesting alternative to expensive, bulky gas counters based on 3He or 10B neutron detection technologies.

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