Energy spectrum and flux of fast neutrons in the atmosphere

Journal Article · Mon Aug 01 04:00:00 EDT 1977 · Phys. Rev., D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.16.537· OSTI ID:7090829

Onge, R N

The energy spectrum of fast neutrons (5--20 MeV) in the atmosphere at the Pfotzer maximum (approx.100 g/cm/sup 2/) was measured at geomagnetic latitude 42/sup 0/N (P/sub c/ = 4.4 GV). The n-..gamma.. detector was a 4.6 x 4.65-cm cylindrical cell of organic liquid scintillator (NE213) coupled to a high-resolution, two-parameter, multiparticle pulse-shape discriminator with a two-parameter (64 x 64) logarithmic pulse-height analyzer. An anticoincidence charged-particle shield completely enclosed the n-..gamma.. detector. The spectral parameter ..beta.. (E) of the differential neutron energy spectrum decreased from 4.4 +- 0.8 in the range 3.5--6.0 MeV to 1.5 +- 1.0 in the range 11--20 MeV. The integrated neutron flux at Pfotzer maximum between 3.5 and 10.0 MeV was 0.36 +- 0.10 neutrons/cm/sup 2/ sec. The implications of these results for the high-energy albedo neutron leakage as a source of the energetic proton flux in the radiation belts are discussed.

• Research Organization: Physics Department, University of New Hampshire, Durham, New Hampshire 03824
• OSTI ID: 7090829
• Journal Information: Phys. Rev., D; (United States), Journal Name: Phys. Rev., D; (United States) Vol. 16:3; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

640200* -- Atmospheric Physics
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARYONS
CHARGED-PARTICLE PRECIPITATION
DISCRIMINATORS
EARTH ATMOSPHERE
ELECTRONIC CIRCUITS
ELECTRONIC EQUIPMENT
ELEMENTARY PARTICLES
ENERGY RANGE
ENERGY SPECTRA
FAST NEUTRONS
FERMIONS
HADRONS
MEV RANGE
MEV RANGE 01-10
MEV RANGE 10-100
NEUTRON FLUX
NEUTRON SPECTRA
NEUTRONS
NUCLEONS
PROTON PRECIPITATION
PULSE ANALYZERS
PULSE CIRCUITS
PULSE DISCRIMINATORS
RADIATION BELTS
RADIATION FLUX
SPECTRA