NSSDCA ID: 1958-004B-03
Mission Name: Sputnik 3The Cosmic Ray Photon Detector was used to study cosmic ray photon fluxes at high altitudes. The instrument used an NaI scintillating crystal and photomultiplier to measure: the counting rate of events where the pulse indicated an energy release in the crystal of more than 35 keV; the value of the photomultiplier anode current; and the value of the photomultiplier intermediate dynode current. The detection energy range was 35 keV to several MeV.
The crystal was a 40 mm diameter cylinder, 40 mm long. It was viewed by a 40 mm diameter photomultiplier tube at one end. A circuit consisting of a capacitor and a neon lamp was used to measure the extremely small currents. The values of the anode and dynode currents were used to characterize the total energy release in the crystal per unit time.
Each of the signals would feed into a relay: the anode current (relay 1), the dynode current (relay 2), and the number of pulses (relay 3). The relay would change position after building up a certain charge (relay 1 and 2), or after accumulating a certain number of pulses (relay 3). The intensity (I) was therefore inversely proportional to the amount of time (T) a relay remained in one position, given by I = K/T(sec), where K was determined by pre-flight calibration to be 2 x 10^9 eV sec for relay 1, 18 x 10^9 eV sec for relay 2, and 2048 counts sec for relay 3.
Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office
Name | Role | Original Affiliation | |
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Prof. S. N. Vernov | Principal Investigator | Moscow State University |