The normalization of solar X-ray data from many experiments
Conversion factor for converting Geiger tube count rates or ion chamber currents into units of incident X ray energy flux in specified passband in normalizing solar X ray data
Wende, C. D.↗
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Solar proton, helium, and medium nuclei (Z is equal to or greater than 6 and equal to or less than 9) observed from the IMP-6 satellite
Proton, helium, and medium nuclei energy spectra have been measured from the Explorer 35 satellite for a recent solar flare. Above 2 MeV/nucleon these spectra are based upon single and dual parameter pulse height analysis in addition to threshold rate counting. Pulse height analysis of medium nuclei is assigned a high priority for telemetry readout so that telemetry does not become saturated by the high proton intensity. In this manner the number of pulse height analyzed medium nuclei has been increased by a factor of approximately 200. Individual medium nuclei have been resolved in the energy interval 8 - 23 MeV/nucleon.
Vonrosenvinge, T. T.↗
Unusual cosmic ray intensity decrease of 18 December 1965
A higher than normal ratio is reported for the decrease of cosmic ray intensity on 18 December 1965. This value was attributed to the depletion of a low rigidity electron component which also contributes to the counting rate of the IMP 3 detector. Significant difference is observed in the onset times recorded by the IMP 3 detector and Alert neutron monitor.
Desai, U. D.↗
A Compton scatter attenuation gamma ray spectrometer
A Compton scatter attenuation gamma ray spectrometer conceptual design is discussed for performing gamma spectral measurements in monodirectional gamma fields from 100 R per hour to 1,000,000 R per hour. Selectable Compton targets are used to scatter gamma photons onto an otherwise heavily shielded detector with changeable scattering efficiencies such that the count rate is maintained between 500 and 10,000 per second. Use of two sum-Compton coincident detectors, one for energies up to 1.5 MeV and the other for 600 keV to 10 MeV, will allow good peak to tail pulse height ratios to be obtained over the entire spectrum and reduces the neutron recoil background rate.
Austin, W. E.↗
A large area detector for neutrons between 2 and 100 MeV
A neutron detector sensitive from 2 to 100 MeV is described. The detector is designed for high altitude balloon flight to measure the flux, energy and direction of albedo neutrons from the earth and to search for solar neutrons. A neutron scatter from a proton is required in each of two liquid scintillator tanks spaced 1 meter apart. The energy of the recoil proton in the first tank is obtained from pulse height analysis of the scintillator output. The energy of the recoil neutron is obtained from its time of flight between the tanks. The detector has been calibrated with 15.3 MeV neutrons and mu mesons. The minimum detectable flux is 10(-4) neutron/sq cm/sec at a counting rate of one per minute; the energy resolution is 12% at 15 MeV and 30% at 100 MeV. The angle between the incoming neutron and the recoil neutron is measured to + or - 10 deg.
Grannan, R. T.↗
Instrument report: Planetary X-ray experiment
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.
Anderson, K. A.↗
Planetary X ray experiment
Design studies for an X-ray experiment using solid state detectors and for an experiment using a proportional counter for investigating Jovian and Saturnian magnetospheres are reported. Background counting rates through the forward aperture and leakage fluxes are discussed for each design. It is concluded that the best choice of instrument appears to have following the characteristics: (1) two separate multiwire proportional counters for redundancy; (2) passive collimation to restrict the field to about 5 deg, wiregrid modulation collimation to about 0.1 deg angular resolution; (3) no active shielding system around the counter body; and (4) light passive shielding around any portion of the counter body exposed to space to absorb most of the cosmic X-ray background.
Anderson, K. A.↗
Channel electron multiplier efficiency for protons of 0.2-10 keV.
The initial results of absolute proton efficiency measurements made in an auroral particle study by sounding rockets are given. The measurements were made at several counting rates from 1000 to 40,000 counts/sec on rocket-borne equipment. The results agree with those of Egidi et al. (1969) in the high energy range and show a disagreement at low energies.
Iglesias, G. E.↗
Electron scattering effects in typical cosmic ray telescopes.
Laboratory measurements have been made of the response of two typical cosmic ray detector systems to electrons between 0.2 and 2.0 MeV. Working laboratory versions of each of these particle telescopes were exposed to the monoenergetic electron beam from a magnetic spectrometer. The results of pulse height and counting rate measurements indicate that electrons scattered from the anticoincidence cup comprise about 25% of the total number arriving at the top of the detector stack. In certain cases, the contribution of these scattered particles to the total number of electrons detected can reach 65%.
Lupton, J. E.↗
Design of the solar X-ray instrument for OSO-H.
The OSO-H solar X-ray instrument monitors X rays from the sun in the energy range 1-300 keV, as well as the charged particle background. The electronics provide accurate logarithmic pulse-height analysis at the high counting rates expected under flare conditions. A high time resolution mode enables tudy the temporal development of a solar flare.
Harrington, T. M.↗
Thermospheric temperature measurement technique.
A method for measurement of temperature in the earth's lower thermosphere from a high-velocity probes is described. An undisturbed atmospheric sample is admitted to the instrument by means of a free molecular flow inlet system of skimmers which avoids surface collisions of the molecules prior to detection. Measurement of the time-of-flight distribution of an initially well-localized group of nitrogen metastable molecular states produced in an open, crossed electron-molecular beam source, yields information on the atmospheric temperature. It is shown that for high vehicle velocities, the time-of-flight distribution of the metastable flux is a sensitive indicator of atmospheric temperature. The temperature measurement precision should be greater than 94% at the 99% confidence level over the range of altitudes from 120-170 km. These precision and altitude range estimates are based on the statistical consideration of the counting rates achieved with a multichannel analyzer using realistic values for system parameters.
Hueser, J. E.↗
A liquid xenon radioisotope camera.
A new type of gamma-ray camera is discussed that makes use of electron avalanches in liquid xenon and is currently under development. It is shown that such a radioisotope camera promises many advantages over any other existing gamma-ray cameras. Spatial resolution better than 1 mm and counting rates higher than one million C/sec are possible. An energy resolution of 11% FWHM has recently been achieved with a collimated Hg-203 source using a parallel-plate ionization chamber containing a Frisch grid.
Zaklad, H.↗
Improved format for radiocardiographic data
Technique involves introduction of radioactive sample into antecubital vein. Scintillation crystal mounted in collimating housing views portion of right and left hearts. As radioactive sample passes through heart, counting rate is measured by crystal and recorded on strip chart. Data is insensitive to geometric effects and other parameters.
Dimeff, J.↗
Counter tube window and X-ray fluorescence analyzer study
A study was performed to determine the best design tube window and X-ray fluorescence analyzer for quantitative analysis of Venusian dust and condensates. The principal objective of the project was to develop the best counter tube window geometry for the sensing element of the instrument. This included formulation of a mathematical model of the window and optimization of its parameters. The proposed detector and instrument has several important features. The instrument will perform a near real-time analysis of dust in the Venusian atmosphere, and is capable of measuring dust layers less than 1 micron thick. In addition, wide dynamic measurement range will be provided to compensate for extreme variations in count rates. An integral pulse-height analyzer and memory accumulate data and read out spectra for detail computer analysis on the ground.
Hertel, R.↗
The diffuse X-ray spectrum from 14-200 keV as measured on OSO-5
The measurement of energy spectrum of the diffuse component of cosmic X-ray flux made on the OSO-5 spacecraft is described. The contributions to the total counting rate of the actively shielded X-ray detector are considered in some detail and the techniques used to eliminate the non-cosmic components are described. Positive values for the cosmic flux are obtained in seven energy channels between 14 and 200 keV and two upper limits are obtained between 200 and 254 keV. The results can be fitted by a power law spectrum. A critical comparison is made with the OSO-3 results. Conclusions show that the reported break in the energy spectrum at 40 keV is probably produced by an erroneous correction for the radioactivity induced in the detector on each passage through the intense charged particle fluxes in the South Atlantic anomaly.
Dennis, B. R.↗
Intensity Oscillation of Low Energy Solar Particles Observed on the IMP 7 Satellite
Solar flare particles in the energy range from 125 to 160 KeV per charge were detected and analyzed by an electrostatic deflection vs. energy instrument on board the Explorer 47 (IMP 7) satellite. A harmonic analysis of the counting rates shows that frequently, the fluctuation of the particle flux can be approximately represented by N(t) = f(t)sin 2 pi nu t where f(t) is a smoothly varying function of t. The oscillation frequency nu varies from flare to flare and is of the order of 2 x .001/sec. The physical implications of the finding are discussed.
Fan, C. Y.↗
A first look at the lunar orbital gamma-ray data.
Preliminary review of data from the radioactivity relief map of the regions of the moon overflown by the Apollo 15 command module. The data represent count rates in the energy band from 0.55 to 2.75 MeV, appropriately corrected and averaged. Review results include the findings that: (1) the major concentrations of radioactivity in the area covered are in the region of Mare Imbrium and Oceanus Procellarum, (2) the highest regions are in the area of Aristarchus in Oceanus Procellarum and a region in eastern Mare Imbrium, and (3) the K/U ratio appears to be lower everywhere than that characteristic of the earth.-
Metzger, A. E.↗
Observations of the binary X-ray source SMC X-1 from OSO-7.
The X-ray source was observed with an X-ray telescope during the time from April 15, 1972 to May 25, 1972. These observations complement the Uhuru results reported by Schreier et al. (1972) and permit an extension of the spectrum to at least 35 keV. Combined with other observations, the data could help determine long term periodic variations, if any exist. The relative exposure and the corrected counting rate of the X-ray telescope during the precession of the satellite axis are shown in a graph.
Ulmer, M. P.↗