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Solar Neutron and Gamma Rays

NSSDCA ID: 1975-033A-02

Mission Name: Aryabhata
Principal Investigator:Dr. Ranjan R. Daniel


This investigation was concerned with the study of energetic neutrons from 20 to 500 MeV and gamma rays from 0.2 to 24 MeV. Although it was intended to measure those particles and photons associated with violent outbursts from the sun, the data were only accumulated in real time from 11 orbits. This permitted a study of atmospheric neutrons and gamma rays. During this time, some events showing sudden increases in gamma ray counting rates were recorded. The detector system consisted of a 12.5-cm-diameter, 1.27-cm-thick csi (TL) crystal coupled to a 12.5-cm-diameter pm tube that was completely enclosed in a 1-cm thick, plastic, scintillator anticoincidence shield. This shield was viewed by four 3.8-cm-diameter pm tubes. A pulse shape discriminator was used for energy deposition in the csi crystal > 5 MeV to distinguish neutrons from gamma rays, and pulse height analysis was accomplished by a 64-channel analyzer. For pulses below 5 MeV, attributed to low-energy gamma rays, three energy-loss windows of 0.2 to 0.4, 0.4 to 1 and 1 to 4 MeV were measured. The charged particle flux was monitored by measuring the coincidence rates between the central and shield crystals as well as the singles rate of the shield. The data rates were scanned every second and transmitted through the spacecraft telemetry. Further details of the experiment are published in 'Pramana', 7, 355, 1976.

Alternate Names

  • Aryabhata/SolarNeutronandGammaRays

Funding Agency

  • Indian Department of Space India


    Additional Information

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    NameRoleOriginal AffiliationE-mail
    Dr. Prabhakar J. LavakareOther InvestigatorTata Institute of Fundamental Research
    Dr. S. V. DamleOther InvestigatorTata Institute of Fundamental Research
    Dr. Ranjan R. DanielPrincipal InvestigatorTata Institute of Fundamental Research
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