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Tueller, J.

Publications and source records attributed to Tueller, J..

60 records · Page 4

NASA NTRS1982

Observations of the galactic center with the GSFC low-energy gamma-ray spectrometer - Preliminary results

The results of measurements made of the gamma ray emission originating from the galactic center are reviewed. The data were gathered with balloon borne gamma ray spectrometers, with the scans centering on 511 keV. Minimum Chi-sq fits were calculated for the recorded emissions, assuming a constant source modulated by the detector response and superimposed on a constant background. A time history of the 511 keV line intensity demonstrated variability in the feature, whereas the continuum spectrum showed a high correlation with previous measurements. An excess in the continuum just below the 511 keV line was taken as an indication of positronium formation.

Paciesas, W. S.↗

NASA NTRS1981

A high resolution measurement of hard X-ray features in the spectrum of Hercules X-1

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Tueller, J.↗

NASA NTRS1980

Abundances of energy spectra of individual iron-secondary elements

Relative abundances of individual Iron-secondary elements have been measured using a balloon-borne 6.6 m ster ionization/Cerenkov detector system. The unusually large geometry factor and single-charge resolution yield empirical atmospheric attenuation curves for individual elements which combine with high statistics at float altitude to yield individual element abundances, extrapolated to the top of the atmosphere, with high precision. Results are presented for top-of-the-atmosphere abundances (relative to iron) of individual elements in the Z range 13-30.

Israel, M. H.↗

NASA NTRS1980

Cosmic-ray abundances in the interval 26 is less than or equal to Z is less than or equal to 40

Results are presented from two balloon flights of an ionization/Cerenkov detector system. Well-defined peaks at nickel (Z = 28) and zinc (Z = 30) yield abundances relative to iron (Z = 26) of 0.05 and 0.006, respectively. About sixty events observed in the interval yield abundances relative to iron similar to those of the standard solar-system.

Israel, M. H.↗

NASA NTRS1979

Cosmic-ray abundances of individual elements in the Z interval between 26 and 30

The relative abundances of Fe, Co, Ni, Cu, and Zn in the cosmic rays have been measured using a large-area balloon-borne electronic detector system. The abundance ratios Ni/Fe and Zn/Fe are 5.0 + or - 0.2% and 0.06 + or - 0.01%, respectively. The Zn abundance is low (40%) compared with the Cameron (1973) (C1) solar system, and is best consistent with the solar system C2 meteorite abundances. The ratios Co/Fe and Cu/Fe, extrapolated to the top of the atmosphere, are 0.68 + or - 0.14% and 0.066 + or - 0.030% respectively; since charge peaks are not resolved at Co and Cu, these results are taken as upper limits of 0.8% and 0.1%, respectively. The Co upper limit is consistent with complete decay of Co-57 at the source and implies a lower limit of 2 years for the time between nucleosynthesis and acceleration of these nuclei.

Tueller, J.↗

NASA NTRS1978

Ultra heavy cosmic ray measurements with a 6.6 sq m-sr electronic detector

A 6.6-sq m-sr electronic detector was employed on a 28-hour balloon flight to obtain abundances of nuclei of Z at least 30 in cosmic rays. A Zn abundance of Zn/Fe = (7 + or - 2) x 10 to the -4th is obtained. The abundances relative to iron of nuclei with Z between 30 and 40 are lower than in the solar-system abundances of Cameron (1973), but individual elements do seem to follow the trend of the solar system.

Love, P.↗