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Schmidt, P. J.

Publications and source records attributed to Schmidt, P. J..

4 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

A measurement of cosmic-ray positron and negatron spectra between 50 and 800 MV

A balloon-borne spark chamber magnetic spectrometer has been used to measure the spectra of cosmic-ray positrons and negatrons at energies between 50 and 800 MV. The data reported here were obtained during two flights from Fort Churchill, Manitoba, in July 1972. The present results indicate that the dominance of negatrons from primary sources, found in earlier experiments above 200 MV, extends down to at least 50 MV. Solar modulation of the positron component is found to be consistent with that of the total electron spectrum, assuming that the positron component is entirely attributable to collisions between cosmic-ray nuclei and the interstellar gas.

Daugherty, J. K.↗
NASA NTRS1974

Measurement of cosmic ray positron and negatron spectra between 50 and 800 MeV

A magnetic spectrometer employing digital-readout spark chambers and a gas Cerenkov threshold counter was used to measure the spectra of cosmic ray negatrons and positrons over the range from 50 to 800 MeV during two balloon flights from Ft. Churchill, Manitoba, in July 1972. A preliminary analysis of data from the first flight suggests that the total electron spectrum in this range has not fully recovered to its condition at solar minimum observed in 1965. The preliminary results also provide upper limits for the positive fraction over the range from 200 to 800 MeV which are consistent with the values found in earlier measurements.

Daugherty, J. K.↗
NASA NTRS1971

The energy spectrum of primary cosmic ray electrons from 2 GeV to 200 GeV.

Use of a balloon-borne counter telescope with a gas Cerenkov counter to measure the energy of primary cosmic ray electrons between 2 and 200 GeV. Electrons are identified by the characteristic electron-photon shower which they produce in a 15 radiation length deep stack of high-Z material interleaved with scintillation counters. Calibrations with monoenergetic electrons up to 14 GeV and monoenergetic protons up to 28 GeV from accelerators are used to develop criteria to statistically separate electrons from proton-induced events. The results from six balloon flights (total exposure time 63 hours) are combined to obtain the electron energy spectrum. Up to about 30 GeV, the spectrum measured in this experiment can be directly checked with calibrations and agrees well with results from other experiments. Above this energy, the flux reported in the present work is somewhat higher than the determinations reported by most other authors. An apparent flattening of the energy spectrum above 50 GeV is not regarded as significant. There is no evidence for a steepening of the spectrum at energies below 200 GeV.

Fanselow, J. L.↗