Direct observation of hyperfine structure in pi mesic X rays.
Ta hyperfine quadrupole effects resolved by high resolution gamma ray detector for pi mesic X rays
Carrigan, R. A., Jr.↗
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Composition of cosmic rays measured in Gemini XI.
Primary cosmic ray nuclei studies during Gemini 2 flight by nuclear emulsion detector with time resolution capability, describing experiment design and equipment operation
Durgaprasad, N.↗
Detection of crystals in CO2 jet plumes.
It is shown that the electron diffraction technique is well suited for studying condensation effects in low-density flows. The possibility of improving the sensitivity and resolution of the detector by using electron multipliers and by increasing the slit distance is examined.
Beylich, A. E.↗
Cosmic dust or other similar outer-space particles location detector
Cosmic dust may be serious radiation hazard to man and electronic equipment caught in its path. Dust detector uses two operational amplifiers and offers narrower areas for collection of cosmic dust. Detector provides excellent resolution as result of which recording of particle velocities as well as positions of their impact are more accurately determined.
Aver, S.↗
Simple model for scanning-angle distribution of planetary albedo gamma-rays.
The planetary atmosphere is scanned from a satellite located at a point at an altitude of 500 km from the subsatellite point on the surface (the altitude of the satellite OSO-3). Results point out the possibility that by scanning a planet from the subsatellite point to the limb with a high resolution gamma ray detector on an orbiting satellite, the mean total baryonic scale height may be unfolded from the angular distribution of the gamma-ray flux without having to determine chemical composition and temperature.
Stecker, F. W.↗
Gamma-ray observations of the galactic centre.
Review of observation data obtained with a portable gas-Cerenkov gamma-ray telescope flown twice from Parana, Argentina (31.8 deg S), to search for gamma radiation from the galactic center. The angular resolution of this detector is not good enough to resolve the source structure controversy, i.e. whether the gamma radiation is coming from point sources or from a diffuse source along the galactic plane. Comparisons with observation data of other investigators are presented and discussed.
Helmken, H. F.↗
K-alpha X-rays from cosmic ray oxygen
Equilibrium charge fractions are calculated for subrelativistic cosmic ray oxygen ions in the interstellar medium. These are used to determine the expected flux of K-alpha rays arising from atomic processes for a number of different postulated interstellar oxygen spectra. Relating these results to the diffuse X-ray background measured at the appropriate energy level suggests an observable line feature. If the flux of low energy cosmic ray oxygen is sufficiently large, K-alpha X-ray line emission from these nuclei will comprise a significant fraction of the total diffuse flux at approximately 0.6 keV. A satellite borne detector with a resolution greater than 30 percent could observe this feature if the subrelativistic interstellar cosmic ray oxygen spectrum is as large as certain theoretical estimates expressed in the text.
Pravdo, S. H.↗
An evolution of X-ray astronomy instrumentation
This paper describes the growth of X-ray astronomy instrumentation from simple, single function, instruments performing survey measurements with crude spectral, spatial and temporal resolution to complex, multiple detector, instruments capable of observing selected phenomena and sources with extremely fine resolution. Examples of solar X-ray instrumentation that are discussed include OSO-IV, Apollo Telescope Mount and proposed Solar Maximum Mission instruments. Stellar X-ray instrumentation examples include UHURU, Astronomy Netherlands Satellite and HEAO-B instruments. Design details are provided and instrument parameters are compared to illustrate the evolutionary process.
Jagoda, N.↗
Proposal to National Aeronautics and Space Administration for continuation of a grazing incidence imaging telescope for X-ray astronomy using sounding rockets
The construction of a high resolution imaging telescope experiment payload suitable for launch on an Astrobee F sounding rocket was proposed. Also integration, launch, and subsequent data analysis effort were included. The payload utilizes major component subassemblies from the HEAO-B satellite program which were nonflight development units for that program. These were the X ray mirror and high resolution imager brassboard detector. The properties of the mirror and detector were discussed. The availability of these items for a sounding rocket experiment were explored with the HEAO-B project office.
Murray, B.↗
Search for planets by spectroscopic methods
Spectroscopic means of detecting the motion of a star around a star-planet barycenter are considered. The precision of such an observation, which requires a radial velocity error of not more than 5 m/sec, is discussed in relation to the spectral resolutions of the detectors utilized. The University of Arizona radial velocity spectrometer is then presented, with particular attention given to the location of the absorption cell in a beam of light from an incandescent bulb, high-accuracy wavelength calibration involving the use of a Fabry-Perot interferometer in front of an echelle spectrograph, and future plans for the use of light reflected from a Fabry-Perot etalon to improve transmittance. On the basis of these techniques, it is expected that radial velocities with accuracies sufficient for the detection of extrasolar planets will be obtained.
Serkowski, K.↗
The spectra and light curves of two gamma-ray bursts
Observations made by the Hard X-ray and Low Energy Gamma-Ray Experiment on board HEAO-1 of the spectra and light curves of two gamma-ray bursts for which localized arrival directions will become available are presented. The burst of October 20, 1977 is found to exhibit a fluence of 0.000031 + or - 0.000005 erg/sq cm over the energy range 0.135-2.05 MeV and a duration of 38.7 sec, while that of November 10, 1977 is found to have a fluence of 0.000021 + or - 0.000008 erg/sq cm between 0.125 and 3 MeV over 2.8 sec. The light curves of both bursts exhibit time fluctuations down to the limiting time resolution of the detectors. The spectrum of the October burst can be fit by a power law of index -1.93 + or -0.16, which is harder than any other gamma-burst spectrum yet reported. The spectrum of the second burst is softer (index -2.4 + or - 0.7), and is consistent with the upper index in the double power law fit to the burst of April 27, 1972.
Knight, F. K.↗
Atmospheric emissions photometric imaging experiment /AEPT/ for Spacelab 1
The atmospheric emissions photometric imaging experiment (AEPI) to be flown on Spacelab 1 is designed to study faint natural and artificial atmospheric emission phenomena. Optical emissions are imaged in the region 2150 A to 7320 A using a television system consisting of two optical channels, one wide-angle and one telephoto. The detection system is an image-enhanced SEC vidicon. A third optical channel images onto the photocathode of a microchannel plate photomultiplier tube that has 100 discrete anodes. Photons are counted for each discrete anode, providing a direct measure of the luminosity of an object viewed by the TV telephoto lens, albeit with low spatial resolution. The AEPI detector is mounted on a two-axis gimbal comprised of a Modified Apollo Telescope Mount Star Tracker (MAST), which provides experiment pointing over a 40-deg x 80-deg range, exclusive of restrictions due to the proximity of other experiments. The pointing stability is 1 arcmin with respect to the spacecraft coordinate system for an exposure of 1 second. The tracking capability is 3.5 deg/s with a stability of 1 arcmin. The detector and pointing system are located on the Spacelab pallet. The experiment is controlled by stored programs resident in the Dedicated Experiment Processor located in the Spacelab module.
Sandie, W. G.↗
Accelerator test of the coded aperture mask technique for gamma-ray astronomy
A prototype gamma-ray telescope employing the coded aperture mask technique has been constructed and its response to a point source of 20 MeV gamma-rays has been measured. The point spread function is approximately a Gaussian with a standard deviation of 12 arc minutes. This resolution is consistent with the cell size of the mask used and the spatial resolution of the detector. In the context of the present experiment, the error radius of the source position (90 percent confidence level) is 6.1 arc minutes.
Jenkins, T. L.↗
An imaging spectrometric observatory for Spacelab
The large payload capacity of the Space Shuttle Orbiter offers the first opportunity to launch into space an instrument able to simultaneously measure the entire spectrum of atmospheric emission, from the extreme UV to the near-IR, with high spectral resolution and high sensitivity while obtaining global and altitude coverage. This capability would provide a database for atmospheric process studies. The Spacelab Imaging Spectrometric Observatory (ISO) comprises an array of five spectrometers designed to make full use of the Space Shuttle as an observing platform for atmosphere remote sensing, and covers the 300-12,000-A wavelength range with a 2-7 A resolution. Area array detectors can scan the entire wavelength range in less than 20 sec and, being two-dimensional, permit spectral imaging in one direction and spatial imaging on the other.
Torr, M. R.↗
Non-local Origin of a Substantial Portion of the Soft X-ray Background
Comparison of the SAS-3 soft X-ray sky survey with the 21-cm neutral hydrogen survey confirms the well-known anticorrelation between the counting rates in the C-band (0.10-0.28 keV) and the column density of neutral hydrogen, and demonstrates that this anticorrelation is significant on all angular scales ranging from that of the general trend from the galactic equator to the poles down to the angular resolution of the detector (2.07 FWHM). Numerous instances of what appear to be soft X-ray shadows of nearly (100-300 pc) 21-cm features, and several bright X-ray regions coincident with holes in the interstellar medium are included in this general correlation. The final set of selected data has an exposure of 2.2 x 10 to the 4th power/sq cm s sr, a sky coverage of 80%, and is free of spurious effects due to charged particles and solar radiations. The validity of the two-component model of the X-ray background, introduced by Davidsen et al. (1977) is examined. In this model the C-band intensity in a given direction is represented as a sum of a constant term, I sub 1, due to unattenuated emission from a local hot bubble in which the solar system is immersed, and a term, I sub 2 exp (N sub H sub th) , due to emission from a diffuse source beyond the neutral hydrogen 2.g., the galactic corona).
Clark, G. W.↗
Vector magnetic field observations with the Haleakala polarimeter
Several enhancements were recently made to the Haleakala polarimeter. Linear array detectors provide simultaneous resolution over a 3-A wavelength range, with spectral resolution of 40 mA. Optical fibers are now used to carry the intensity-modulated light from the rotating quarter-wave plate polarimeter to the echelle spectrometer, permitting its removal from the spar to a more stable environment. These changes, together with improved quarter-wave plates, reduced systematic errors to a few parts in 10,000 for routine observations. Examples of Stokes profiles and derived magnetic field maps are presented.
Mickey, D. L.↗
Mass resolution optimization in a large isotopic composition experiment
A range-energy experiment was built to measure the isotopic composition of galactic cosmic rays. An enrichment of neutron rich isotopes, 22Ne and (25Mg + 26Mg) in particular, when compared to the solar composition is shown. A rich statistics measurement of these and other neutron-rich isotopes in the galactic flux yields information to the source of these particles. A computer simulation of the experiment was used to estimate the instrument resolution. The Cherenkov detector light collection efficiency, was calculated. Absorption of light in the radiator was considered to determine the optimum Cherenkov medium thickness. The experiment will determine the isotopic composition for the elements neon through argon in the energy range 300 to 800 MeV per nucleon.
Esposito, J. A.↗
Modular detector for deep underwater registration of muons and muon groups
Registration and identification of muons and muon groups penetrating into the ocean depth, can be performed using a modular multilayer detector with high resolution bidimensional readout - deep underwater calorimeter (project NADIR). Laboratory testing of a prototype sensor cell with liquid scintillator in light-tight casing, testifies to the practicability of the full-scale experiment within reasonable expences.
Demianov, A. I.↗