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Solid-State Proton-Alpha Particle Telescope

NSSDCA ID: 1971-096A-02

Mission Name: S-Cubed A
Principal Investigator:Prof. Theodore Allan Fritz


This experiment contained two telescopes, each consisting of two surface barrier solid-state silicon detector elements. The low-energy range telescope had detectors of thicknesses 100 and 300 micrometers, and was mounted behind a 2.2-kG broom magnet to sweep out electrons with energies less than 300 keV. This telescope measured the flux of protons in six channels covering the energy range 24.3 to 300 keV. The heavy ion telescope had detectors of thicknesses 3.4 and 100 micrometers. This telescope uniquely identified the presence of protons, alpha particles (Z=2), and two groups of heavier ions, (Li,Be,B) and (C,N,O), plus ions with Z>=9. The heavy ion telescope measured proton fluxes in six channels covering the energy range 365 to 872 keV, and the fluxes of alpha particles in the energy ranges 1.16 to 1.74 keV and 1.74 to 3.15 keV. It measured the fluxes of Li, Be, and B ions in the ranges 3.6 to 7.1 MeV, 6.1 to 9.7 MeV, and 8.7 to 12.2 MeV, respectively, and the fluxes of C, N, and O ions in the ranges 12.1 to 15.7 MeV, 15.6 to 19.2 MeV, and 19.1 to 22.7 MeV, respectively. And it measured the flux of Z>=9 ions with energies > 20 MeV. In addition, electrons of energy greater than 300 keV were detected via the coincidence mode of the low-energy range telescope. Both telescopes were mounted at 90 deg to the satellite spin axis, and had full conical viewing angles of about 11 deg. NSSDC has all the data from this investigation, except the uncondensed tapes for the period from launch to May 1973. Further details regarding experiment parameters may be found in Longanecker, G. W. and R. A. Hoffman, "S-Cubed-A spacecraft and experiment description," J. Geophys. Res., v. 78, n. 22, p.4711, August 1973, and in Fritz, T. A., "The SSS Solid State Proton Experiment, Part I: design, operation and calibrations" (TRF B33771) and in McKinnon, J. A., and T. A. Fritz, "SSS Solid State Proton Experiment, Part II: mean energy of a finite energy passband," NOAA Technical Memorandum ERL SEL-44, Space Environment Laboratory, Boulder, Colorado, April 1976 (TRF B33795).

Alternate Names

  • Measurement and Study of Magnetospheric Storms and Ring Currents
  • S-CubedA/Solid-StateProton-AlphaParticleTelescope

Facts in Brief

Mass: 2.02 kg
Power (avg): 1 W

Funding Agency

  • NASA-Office of Space Science Applications (United States)


  • 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
Prof. Theodore Allan FritzPrincipal InvestigatorNOAA Environmental Research
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