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Neutron Detectors

NSSDCA ID: 1964-040A-03

Mission Name: Vela 2A
Principal Investigator:Dr. John R. Asbridge


The neutron detector was designed to monitor neutron signals from nuclear explosions in space and to establish background characteristics for neutron detectors exposed to neutrons and showers produced in the spacecraft by cosmic rays. The detector used a large polyethylene moderator to thermalize incident neutrons, the thermal neutrons were detected in two helium 3-filled proportional counters. Each counter had its own power supply and amplifier to afford greater reliability. Neutrons in the approximate range 1 - 100 MeV were counted and read out each second. The detector also reacted to (but did not distinguish) protons greater than 25 MeV in energy, thus it provided a simple indication of solar proton activity. The experiment worked well over the period of major data coverage.

Alternate Names

  • Vela2A/NeutronDetectors


  • Space Physics: Magnetospheric Studies

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Dr. John R. AsbridgePrincipal InvestigatorLos Alamos National
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