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Results for “SPARK CHAMBER”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1969

Gamma ray astronomy

Detector and spark chamber systems for gamma ray astronomy in first-generation experiments

Fichtel, C. E.↗
NASA NTRS1971

The gamma ray experiment for the Small Astronomy Satellite B (SAS-B)

A magnetic core digitized spark chamber gamma ray telescope has been developed for satellite use. The detector has the following characteristics: effective area = 500 cu/cm, solid angle = 1/4 SR; efficiency (high energy) = 0.29; and time resolution of better than two milliseconds.

Fichtel, C. E.↗
NASA NTRS1972

Gamma ray satellite to be launched from Africa

The announcement is presented of the launch of NASA's Small Astronomy Satellite B (SAS-B) on 2 Nov. 1972, to study gamma rays. The launch is to be from the Italian-operated San Marco Equatorial Range in the Indian Ocean for ease in acquiring an equatorial orbit. The spacecraft systems described include: stabilization and control, communication, and spark chamber gamma ray telescope. The results of Uhuru (Explorer 42) are also presented.

Allaway, H. G.↗
NASA NTRS1971

Techniques for gamma rays.

The detecting systems used in high energy astrophysics are generally more similar to particle detectors than to optical devices. The basic design of the gamma ray instrument depends on whether the energy range is below about 10 MeV and therefore in the region where the Compton effect predominates in the absorption of the gamma-rays, or above that energy where electron-positron pair production is most important. The most usual approach to the detector system in the lower of the two energy intervals is to use a scintillation counter in the center of the detector system to absorb the photons and permit a measure of their energy, and to surround it by another detector which is employed as an active anticoincidence shield to discriminate against charged particles. In the gamma-ray interval above about 10 MeV, the very low flux of gamma rays and the high particle background has directed the development of high energy gamma-ray telescopes towards complicated techniques and large detector arrays. As a result, several investigators have now turned to the spark chamber as the heart of a detector system. Generally, it is surrounded by an anticoincidence system and is triggered by a counter telescope.

Fichtel, C. E.↗
NASA NTRS1971

Instrumentation for the measurement of high energy phenomena on NASA spacecraft.

High energy astrophysical observations will be conducted primarily from the Small Astronomy Satellites (SAS) and the High Energy Astronomy Observatories (HEAO). The first satellite (SAS A) will carry a set of collimated proportional counters to conduct a high sensitivity, high spatial resolution, all sky survey for X-ray sources. The objective of SAS B will be to search for celestial gamma-ray sources and regions and to measure the flux and energy spectrum of any sources located. A wire grid digitized spark chamber will be the prime detection instrument. The instrumentation of SAS C will consist of modulation collimators, slot collimators, and proportional counters.

Opp, A. G.↗
NASA NTRS1972

Gamma-ray observations of the galactic center and some possible point sources.

A 0.5 x 0.5-m digitized spark-chamber gamma-ray telescope was flown on three balloon flights to look at the galactic center region, Virgo, and the Crab Nebula. An excess flux above atmospheric background of over 4 standard deviations was found for gamma-rays exceeding 100 MeV coming from the galactic center region, but there was no statistically significant excess in the 50-100 MeV interval. As a result, there is only a 6% chance that Compton or synchrotron radiation from electrons with a power-law spectrum having an exponent of 2.6 could make as much as a 50% contribution to the gamma-radiation in this energy range.

Fitchtel, C. E.↗
NASA NTRS1972

Superconducting magnetic spectrometer for cosmic ray nuclei.

This paper describes the design, calibration, and operation of a magnetic spectrometer for particle astronomy. The spectrometer consists of a superconducting magnet, optical spark chambers, scintillation detectors, and associated electronics. The instrument has been flown in a balloon gondola to 4.8 g/sq cm residual atmosphere, where it was used to analyze the charge and differential rigidity spectra of primary nuclei from 5 to 100 GeV/c.

Smith, L. H.↗
NASA NTRS1972

Search for 1/3e and 2/3e charged quarks in the cosmic radiation at 2750-m altitude.

A scintillation counter telescope consisting of eight liquid scintillation counters and four wide-gap spark chambers was used to search for particles with electric charge 1/3e and 2/3e in cosmic rays at 2750 m above sea level. No such particles were detected during the 1500-hr experimental run. Upper limits on the vertical fluxes are established, and estimates of the corresponding sea-level fluxes are made for comparison with previous results.

Cox, A. J.↗
NASA NTRS1972

A search for antihelium in primary cosmic radiation.

A search for anti-alpha-particles in the primary cosmic radiation has been carried out, and a new upper limit for these particles in the range 0.2-4.3 GeV per nucleon has been obtained. At the 95 per cent confidence level the upper limit is found to be 0.14 per cent of the alpha-particle flux. The instrument used for this purpose is a magnetic spectrometer employing spark chambers for determining particle trajectories and time-of-flight measurement for the rejection of upward-moving particles. Implications of these results for various models of the sources of cosmic radiation are discussed.

Evenson, P.↗
NASA NTRS1972

Gamma ray emission from the region of the galactic center

A combination nuclear emulsion-spark chamber gamma ray (E=100 MeV) telescope was used to study the region of sky that includes the Galactic Center. 95% confidence upper limits on the flux from the reported sources G gamma 2 - 3 and Sgr gamma-1 were placed at 4.4 and 8.8 x 10 to the minus 5th power protons/sq cm-sec, and a similar limit on the emission from the Galactic Center as a point source (plus or minus .75 degrees) was placed at 3.3 x 10 to the minus 5th power protons/sq cm-sec. No enhanced emission was observed from the Galactic Plane (plus or minus 6 degrees) and an upper limit of 2 x 10 to the minus 4th power protons/sq cm-sec rad/ was obtained.

Dahlbacka, G. H.↗
NASA NTRS1973

Celestial diffuse gamma radiation above 30 MeV observed by SAS-2

The Small Astronomy Satellite (SAS)-2, launched on November 15, 1972, carried into orbit a 32-deck magnetic-core digitized spark chamber gamma ray telescope to study celestial gamma radiation in the energy range above 30 MeV. In the study of several regions with b sub 2 15 deg, a finite, diffuse flux of gamma rays with a steep energy spectrum in the energy region from 35 to 200 MeV is observed. Representing the energy spectrum by a power law of the form dJ/dE = AE to - alpha power over this energy range, alpha is found along with the integral flux above 100 MeV. Combining this result with existing low energy gamma ray data yields an energy spectrum which is not a simple power law in energy, as in the X-ray region, but which demonstrates first an increase and then a decrease in slope, consistent within uncertainties with that predicted by cosmological theories, including the continuous production of high energy gamma rays primarily from neutral pi mesons throughout the history of the universe.

Fichtel, C. E.↗