Energy spectrum and flux of high--energy neutrons at balloon altitudes

Journal Article · Wed Dec 01 04:00:00 EST 1976 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA081i034p06211· OSTI ID:7236570

Lockwood, J A; Chen, C; Friling, L A; Onge, R N.S.

The energy spectrum and flux of neutrons from E/sub n/ approx. = 2 MeV were measured with organic liquid scintillators near the top of the atmosphere during a balloon flight in 1973 at 4.2--2.9 g/cm/sup 2/ over Palestine, Texas (lambda=42/sup 0/N). Two cylindrical liquid scintillators of dimensions 5 cm x 5 cm and 12.5 cm x 12.5 cm filled with NE 213 were used to cover the neutron energy range from 2 to 75 MeV. Paulse shape discrimination on each detector separated the protons and alphas produced within the scintillator by neutron interactions from the electrons produced by gamma rays. The response functions for mono-energetic neutrons up to E/sub n/ = 75 MeV were determined from accelerator calibrations. The neutron leakage current from 2 to 10 MeV is given by R = (0.25 - 0.05) E/sup -1.8 +- 0.1/ neutron/cm/sup 2/ s MeV, and at 20, 30, 50, and 75 MeV the leakage rates are (1.6 +- 0.4) x 10/sup -3/, (1.15 + 0.20 - 0.25) x 10/sup -3/, (8.0 + 2.0 /sup -/1.4) 10/sup -4/, and (6.3 +- 1.3) x 10/sup -4/ neutron/cm/sup 2/ s MeV, respectively. (AIP)

• Research Organization: Physics Department, University of New Hampshire, Durham, New Hampshire 03824
• OSTI ID: 7236570
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 81:34; ISSN JGREA
• Country of Publication: United States
• Language: English

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71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BALLOONS
BARYONS
EARTH ATMOSPHERE
ELEMENTARY PARTICLES
ENERGY RANGE
FAST NEUTRONS
FERMIONS
FUNCTIONS
HADRONS
LIQUID SCINTILLATION DETECTORS
MAGNETOSPHERE
MEASURING INSTRUMENTS
MEV RANGE
MEV RANGE 10-100
NEUTRON DETECTION
NEUTRON FLUX
NEUTRON LEAKAGE
NEUTRON SPECTRA
NEUTRONS
NUCLEONS
RADIATION DETECTION
RADIATION DETECTORS
RADIATION FLUX
RESPONSE FUNCTIONS
SCINTILLATION COUNTERS
SPECTRA