The spectra and intensity of electrons in the radiation belts.
Electron spectra, pitch angle distributions and total ionization measured throughout radiation belts by satellite magnetic spectrometer and integrating ionization chamber
RADIATION BELT↗
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Results for “IONIZATION 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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MARINER II- HIGH-ENERGY-RADIATION EXPERIMENT
Measurement of radiation in space by two geiger-muller counters and argon filled ionization chamber on mariner ii space probe
MARINER II SPACE PROBE↗
Relative abundances of elements (20 or = Z or = 28) at energies up to 70 GeV/amu using relativistic rise in ion chambers
The results of a new balloon borne cosmic ray detector flown from Palestine, TX in Sept., 1982 are discussed. The exposure of 62 square meter-ster-hr is sufficient to prove the concept of using gas ionization chambers as energy measuring devices in the relativistic rise region. The abundances, relative Fe-26, of the pure secondaries Cr-22 and Ti-24, the pure primary Ni26, and the mixed primary and secondary Ca-20 between 6 and 70GeV/amu were measured.
Barthelmy, S. D.↗
Proton and Electron Threshold Energy Measurements for Extravehicular Activity Space Suits
Construction of ISS will require more than 1000 hours of EVA. Outside of ISS during EVA, astronauts and cosmonauts are likely to be exposed to a large fluence of electrons and protons. Development of radiation protection guidelines requires the determination of the minimum energy of electrons and protons that penetrate the suits at various locations. Measurements of the water-equivalent thickness of both US. and Russian EVA suits were obtained by performing CT scans. Specific regions of interest of the suits were further evaluated using a differential range shift technique. This technique involved measuring thickness ionization curves for 6-MeV electron and 155-MeV proton beams with ionization chambers using a constant source-to-detector distance. The thicknesses were obtained by stacking polystyrene slabs immediately upstream of the detector. The thicknesses of the 50% ionizations relative to the maximum ionizations were determined. The detectors were then placed within the suit and the stack thickness adjusted until the 50% ionization was reestablished. The difference in thickness between the 50% thicknesses was then used with standard range-energy tables to determine the threshold energy for penetration. This report provides a detailed description of the experimental arrangement and results.
Moyers, M. F.↗
On the interpretation of observed data from C-dE/dx detectors
The paper describes a Cerenkov detector system designed to obtain abundances and energy spectra of cosmic ray nuclei above charge 12 and above 350 MeV/nucleon. The detector system consists of three pulse ionization chambers, a Lucite Cerenkov counter and a plastic scintillation-counter hodoscope. The data analysis follows from the standard dE/dx-C technique. It is shown that by using the relativistic ionization rise, the resolution and pulse height corresponding to charged particles of Beta ? 1 in Cerenkov detectors can be determined. Least-squares-fit procedures are used to obtain area and time variations of detector response from flight data and to extract elemental abundances from data with charge resolution of roughly 0.3 charge units.
Benegas, J. C.↗
The heavy nuclei experiment on HEAO-3
The HEAO-3 experiment to study the heavy and ultraheavy nuclei in cosmic radiation is described. The array is double-ended and consists of three main elements. Two pressure chambers, filled with an argon-methane mixture at about 850 torr, each contain two x-y hodoscopes made of wires spaced 1 cm apart and three parallel plate ionization chambers. Between the pressure chambers is mounted a Cerenkov counter composed of two layers of Pilot 425 radiator looked at by eight photomultipliers. The instrument is designed to achieve a charge resolution of 0.3 charge units over the charge range 17-120, which requires a measurement accurate to 0.6 percent at Z = 100. Examination of selected data shows that the instrument has the intrinsic resolution needed.
Binns, W. R.↗
Ultraheavy cosmic rays - HEAO-3 results
The instrumentation and results from the Heavy Nuclei experiment on the HEAO 3 satellite are described. Six independently analyzed dual-gap ionization chambers measured the energy loss of the cosmic rays while a Cerenkov counter with 8 independently analyzed photomultipliers viewed two sheets of Pilot 425 plastic in a white box. Trajectories of the cosmic ray nuclei were determined in multiwire ionization hodoscopes. Variations in abundances were observed to be imperfectly ordered in terms of the first ionization potential, and volatility was also ruled out as the controlling factor. A predicted drop in abundance after Ba-56 was found, along with another sharp fall above Pb-82. Only one actinide-type event was detected during the 14 mos of viewing, a result consistent with other findings but which testifies against r-process formation.
Israel, M. H.↗
Liquid xenon time projection chamber for gamma rays in the MeV region: Development status
The feasibility of a large volume Liquid Xenon Time Projection Chamber (LXe-TPC) for three dimensional imaging and spectroscopy of cosmic gamma ray sources, was tested with a 3.5 liter prototype. The observation of induction signals produced by MeV gamma rays in liquid xenon is reported, with a good signal-to-noise ratio. The results represent the first experimental demonstration with a liquid xenon ionization chamber of a nondestructive readout of the electron image produced by point-like charges, using a sense wire configuration of the type originally proposed in 1970 by Gatti et al. An energy resolution as good as that previously measured by the millimeter size chambers, was achieved with the large prototype of 4.4 cm drift gap.
Aprile, E.↗
Energy spectra of elements with 18 less than or equal to Z less than or equal to 28 between 10 and 300 GeV/amu
The HEAO-3 Heavy Nuclei Experiment is composed of ionization chambers above and below a plastic Cherenkov counter. The energy dependence of the abundances of elements with atomic number, Z, between 18 and 28 were measured at very high energies where they are rare and thus need the large area x time of this experiment. The measurements of the Danish-French HEAO-3 experiment were extended to higher energies, using the relativistic rise of ionization signal as a measure of energy, and determine source abundances for Ar and Ca.
Jones, M. D.↗
Energy spectra of elements with 18 or = Z or = 28 between 10 and 300 GeV/amu
The HEAO-3 Heavy Nuclei Experiment is composed of ionization chambers above and below a plastic Cerenkov counter. The energy dependence of the abundances of elements with atomic number, Z, between 18 and 28 at very high energies where they are rare and thus need the large area x time are measured. The measurements of the Danish-French HEAO-3 experiment (Englemann,, et al., 1983) are extended to higher energies, using the relativistic rise of ionization signal as a measure of energy. Source abundances for Ar and Ca were determined.
Jones, M. D.↗
Photoabsorption cross section of acetylene in the EUV region
The measurement of the absolute photoabsorption cross sections of C2H2 in the 175-740 A region by means of a double ionization chamber is reported. The continuum background source is the synchrotron radiation emitted by the Wisconsin 240 MeV electron storage ring. It is found that the cross sections range from 2 to a maximum of 36 Mb. Two new Rydberg series are identified and the cross section data are applied in the analysis of various sum rules. From the rules, it is shown that the data of C2H2 in the 580-1088 A range may be too low, while the measured ionization transition moment may be too high.
Wu, C. Y. R.↗
Decomposition of Electron Ionization Mass Spectra for Space Application Using a Monte-Carlo approach
Rationale: Quadrupole mass spectrometers equipped with an electron ionization (EI) sources have been widely used in space exploration to investigate the composition of planetary surfaces and atmospheres. However, the complexity of the samples and the minimal calibration for the fragmentation of molecules in the ionization chambers have prevented the deconvolution of the majority of the mass spectra obtained at different targets, thus limiting the determination of the exact composition of the samples analyzed. We propose a Monte‐Carlo approach to solve this issue mathematically. Methods: We decomposed simulated mass spectra of mixtures acquired with unit resolving power mass spectrometers and EI sources into the sum of the single components fragmentation patterns weighted by their relative concentration using interior‐point least‐square fitting. To fit compounds with poorly known fragmentation patterns, we used a Monte‐Carlo method to vary the intensity of individual fragment ions. We then decomposed the spectrum thousands of times to obtain a statistical distribution. Results: By performing the deconvolution on a mixture of seven different molecules with interfering fragmentation patterns (H2O, O2, CH4, Ar, N2, C2H4, and C2H6) we show that this approach retrieves the mixing ratio of the individual components more accurately than regular mass spectra decomposition methods that rely on fragmentation patterns from general databases. It also provides the probability density function for each species's mixing ratio. Conclusions: By removing the solution degeneracy in the decomposition of mass spectra, the method described herein could significantly increase the scientific retrieval from archived space flight mass spectrometry data, where calibration of the ionization source is no longer an option.
Thomas Gautier↗
Observations of the Van Allen Radiation Regions During August and September 1959
An integrating ionization chamber and a single Geiger counter were flown on United States satellite Explorer VI in an elliptical orbit extending to 48,000 km. In addition to the Van Allen inner zone and the great outer zone, a stable and distinct intermediate zone was detected throughout August and September 1959. The outer-zone intensity showed a large decrease following the sudden commencement of a geomagnetic storm. Later in the storm the outer zone increased to much in excess of its prestorm level. During stable periods the outer zone was fairly constant and less intense than it had been observed to be with Pioneer III or Pioneer IV or the first Soviet cosmic rocket. Cosmic-ray background counting rates were reached on most passes in August and Septmeber near apogee of the satellite. The radiation ?dumped? from the outer zone during the geomagnetic storm fits very well with the intensity and latitude distribution required to account for balloon observations of auroral X rays made during the IGY period. This paper is based on preliminary analysis of Explorer VI data.
Arnoldy, R. L.↗
A soft x-ray photoionization detector
Soft X-ray photoionization detection with simple ceramic radiation detector as direct-current gas-filled ionization chamber
PHOTOIONIZATION↗
Densitometer system for liquid hydrogen has high accuracy, fast response
Developmental densitometer system for cryogenic liquids uses two balanced ionization chambers containing xenon gas, with X rays as the radiation source. The X rays are heavily filtered with a lead shield to make the energy spectrum much less dependent on the voltage applied to the X ray tube.
Source record↗
Miniature electrometer preamplifier effectively compensates for input capacitance
Negative capacitance preamplifier using a dual MOS /Metal Oxide Silicon/ transistor in conjunction with bipolar transistors is used with intracellular microelectrodes in recording bioelectric potentials. Applications would include use as a pickup plate video amplifier in storage tube tests and for pH and ionization chamber measurements.
Burrous, C. N.↗
The southern sky survey payload
Measurements on ultraviolet fluxes from stars and nebulosities by rockets carrying photomultiplier and ionization chamber detectors
STELLAR RADIATION↗
Mariner-Mars science subsystem
Mariner-Mars science subsystem - cosmic ray telescope, cosmic dust detector, trapped radiation detector, ionization chamber, plasma probe, magnetometer, and data processing
MARINER IV SPACE PROBE↗