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Boron 10 absorption cross sections from counting ratios measurements of boron trifluoride proportional counter used to monitor neutron fluxes
X ray spectra of Sco XR-1, Cyg XR-1 and Cyg XR-2 for proton energy range 1.5-13 kev from proportional counter measurements
Balloon-borne proportional counters to measure X rays intensity and spectral distribution from Taurus X-1 and Cygnus X-1
Neutron capture cross sections of molybdenum, tantalum, and U-238 and neutron flux spectrum measurements using He-3 proportional counter
Sco X-1 line spectra search in X ray spectrum by rocket-borne proportional counters, noting iron line emission
Solar X-ray emission localization, examining spatial distribution by rocket-borne collimated proportional counter
Extragalactic objects 3C 273 NGC 5128 and M87 X ray emission detection, using proportional counters on Aerobee 150 rocket
Ionized gas density monitor as meteoroid detector, describing operation in ionization chamber, proportional counter and glow tube modes
X ray spectra of discrete sources in Cygnus data from rocket-borne proportional counter
Proton recoil measurements of PuBe neutron source spectra, using pressurized hydrogen spherical proportional counter and liquid scintillator measurements
Virgo XR-1 X rays observation with rocket-borne proportional counters, noting photo index or bremsstrahlung temperature consistency with spectrum
The modifications to the Houston/MSC design of the gas proportional counter flight electronics system are discussed. The following modifications are described: charge amplifier bandwidth improvements, power converter redesign, serial data output buffer, second differentiator, and risetime discriminator. In addition, the redesign of the stellar aspect camera is discussed along with developments in thin film fabrication.
A position sensitive proportional counter for use in an X-ray diffractometer is developed to permit drastic reductions in the power and weight requirements of the X-ray source and the elimination of the power, weight, and complexity of a moving slit. The final detector constructed and tested has a window spanning 138 and a free standing anode curved along an arc of 7.1 cm radius. Demonstration spectra of a quartz sample in a Debye-Sherrer geometry indicate a spatial resolution of 0.4 - 0.5 mm (0.3 - 0.4 theta). The lunar diffractometer consumed 25 watts in the X-ray generator and weighed about 20 pounds.
Two rocket-borne proportional counters, each with 650 sq c, met area and 1.8 x 7.1 deg FWHM rectangular mechanical collimation, surveyed the Cygnus region in the 2 to 20 keV energy range on two occasions. X-ray spectral data gathered on 21 September 1970 from discrete sources in Cygnus are presented. The data from Cyg X-1, Cyg X-2, and Cyg X-3 have sufficient statistical significance to indicate mutually exclusive spectral forms for the three. Upper limits are presented for X-ray intensities above 2 keV for Cyg X-4 and Cyg X-5 (Cygnus loop). A search was made on 9 August 1971 for a diffuse component of X-rays 1.5 keV associated with an interarm region of the galaxy at galactic longitudes in the vicinity of 60 degrees. A statistically significant excess associated with a narrow disk component was detected. Several possible emission models are discussed, with the most likely candidate being a population of unresolvable low luminosity discrete sources.
A double-chambered gas proportional counter was constructed to detect and identify solar wind ions after acceleration by a high voltage power supply. It was determined that the best method of detecting deuterium in the solar wind is to use a tritium target as proposed for IMP H and J. The feasibility of detecting H(+) and He(+) ions of interstellar origin is considered. A program is described to carry out ground-based astronomical observations of faint, diffuse optical emission lines from interstellar gas. Hydrogen and oxygen emission lines from galactic sources were detected and the galactic and geocoronal H alpha and beta lines were clearly resolved.
An ultraminiature X-ray fluorescence spectrometer was developed which can obtain data on element composition not provided by present spacecraft instrumentation. The apparatus employs two radioisotope sources (Fe-55 and Cd-109) which irradiate adjacent areas on a soil sample. Fluorescent X-rays emitted by the sample are detected by four thin-window proportional counters. Using pulse-height discrimination, the energy spectra are determined. Virtually all elements above sodium in the periodic table are detected if present at sufficient levels. Minimum detection limits range from 30 ppm to several percent, depending upon the element and the matrix. For most elements, they are below 0.5 percent. Accuracies likewise depend upon the matrix, but are generally better than plus or minus 0.5 percent for all elements of atomic number greater than 14. Elements below sodium are also detected, but as a single group.
Design studies for an X-ray experiment to investigate planetary magnetospheres using solid state detectors, or proportional counters are reported. The detectors, background counting rate, and leakage fluxes are discussed. It is concluded that the best choice of instruments appears to be two separate multiproportional counters for redundancy.
An analysis was conducted of a gas window photoionization device for studying cosmic X-rays in the region 20 eV to 1 keV. The detecting element is an argon proportional counter whose window is a two-dimensional supersonic gas jet. Spectroscopic features of the incoming radiation can be determined by the choice of gas forming the jet (as well by the fluid dynamic parameters of the flow). The choice of gas can be made from pure substances and/or compounds with Z between 1 and 10. The counter walls can be prepared for selective analysis of the extreme ultraviolet radiation.