A SCINTILLATION COUNTER WITH NEUTRON AND GAMMA-RAY DISCRIMINATORS

Journal Article · Tue Mar 31 23:00:00 EST 1959 · Nuclear Instr. & Methods

DOI:https://doi.org/10.1016/0029-554X(59)90067-9· OSTI ID:4258058

Brooks, F D

Certain organic scintillators, notably anthracene, stilbene and quaterphenyl crystals and oxygen-free liquid scintillators, show an effectively longer scintillation decay time for heavily ionizing particles such as alpha- particles or protons than for electrons. A scintillation counter is described which distinguishes fast neutrons from gammaa-rays by means of the different decay times of recoil proton and Compton electron scintillations, respectively. Measurements of the protonclectron resolution for different scintillators are describel. It is found, for example, that using a one-inch thick stilbene crystal, 2 Mev neutrons may be detected with 9. 5% efficiency while the detection efficiency for 2 Mev gamma-rays is reduced by decay time discrimination to less than 0.007%. An application of the counter for fission cross section measurements by fission neutron detection is described. The decay time properties of the scintillators are discussed and the longer decay time for protenas (or alpha-particles) is interpreted in terms of slow (10/sup -7/ sec) ion recombination processes in the scintillators; these processes produce a slow component in the scintillation decay and in a proton scintillation the proportion of slow component is more than in an electron scintillation. (auth)

• Research Organization: United Kingdom Atomic Energy Authority, Harwell, Berks, Eng.
• NSA Number: NSA-13-014479
• OSTI ID: 4258058
• Journal Information: Nuclear Instr. & Methods, Journal Name: Nuclear Instr. & Methods Vol. Vol: 4
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALPHA PARTICLES-- ANTHRACENE-- COMPTON EFFECT-- EFFICIENCY-- ELECTRONS-- ENERGY RANGE-- FAST NEUTRONS-- GAMMA RADIATION-- HALF- LIFE-- IONIZATION-- IONS-- MEASURED VALUES-- OXYGEN-- PHOSPHORS-- POLYPHENYLS-- PROTONS-- RECOILS-- RESOLUTION-- SCINTILLATION COUNTERS-- STILBENE
CROSS SECTIONS-- FISSION-- MEASURED VALUES-- NEUTRONS
INSTRUMENTS