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Waddington, C. J.

Publications and source records attributed to Waddington, C. J..

At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

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.↗
NASA NTRS1980

The charge distribution of heavy cosmic ray nuclei

In the analysis of data from a balloon flight of a detector of cosmic ray nuclei designed to study the isotopic composition, the charge composition has been measured with high resolution. Some 24,000 nuclei with Z not less than 10 have been measured with a charge resolution of 0.2 charge units. The limitations on the significance of these results are those due to the corrections for the effects of matter in the detectors and the residual atmospheric matter. These corrections are discussed and corrected results are compared with other high resolution charge spectra reported recently.

Freier, P. S.↗
NASA NTRS1980

Some isotopic abundances in the cosmic radiation

Cosmic ray nuclei with Z not less than 10 have been observed in a detector which measures charge with a double scintillator-Cherenkov array and mass by combining the Cherenkov signal with residual range measured in nuclear emulsions. Results are presented for the isotopic analyses of Al, Ca, Sc, Mn, Fe, Co, Ni and Cu in the energy range 300-800 MeV/amu.

Young, J. S.↗
NASA NTRS1980

Interactions of energetic heavy ions with various nuclei

Argon and iron nuclei accelerated to about 1.8 GeV/amu at the Bevalac have been observed interacting in various target media. The results have been compared with the predictions of the semi-empirical models and other experimental measurements.

Nair, K. R. V.↗
NASA NTRS1978

The charge and energy spectra of heavy cosmic-ray nuclei

A charged-particle detector array flown on a high-altitude balloon has detected and measured some 30,000 cosmic-ray nuclei with Z of at least 12. The charge spectrum at the top of the atmosphere for nuclei with energies greater than 650 MeV/n and the energy spectrum for energies between 650 and 1800 MeV/n are reported and compared with previously published results. The charge spectrum at the 'source' of cosmic rays is deduced from these data and compared with a recent compilation of 'galactic' abundances.

Scarlett, W. R.↗
NASA NTRS1978

A comment on the validity of fragmentation parameters measured in nuclear emulsions

Evidence is reexamined which has been cited as suggesting serious errors in the use of fragmentation parameters appropriate to an airlike medium deduced from measurements made in nuclear emulsions to evaluate corrections for certain effects in balloon-borne observations of cosmic-ray nuclei. Fragmentation parameters for hydrogenlike interactions are calculated and shown to be in overall good agreement with those obtained previously for air. Experimentally measured fragmentation parameters in emulsion are compared with values computed semiempirically, and reasonable agreement is indicated.

Waddington, C. J.↗
NASA NTRS1978

The cosmic ray nuclides

The relative abundances of individual nuclides in cosmic rays are discussed. Data on the H-He nuclide quartet are reviewed, along with experimental results for stable nuclides with Z of at least 3. Detailed attention is given to the ratios C-12/C-13, N-15/N, and O-17+18/O, as well as to the light-heavy nuclei, the iron group, and radionuclides. The resolution of the low- and medium-energy detectors aboard the ISEE satellite is illustrated.

Waddington, C. J.↗
NASA NTRS1977

Intensity of primary cosmic-ray electrons of energy exceeding 8 GeV

Results are reported for measurement of the intensity and energy spectrum of primary cosmic-ray electrons with a spark-chamber-counter-emulsion detector flown at a mean altitude of 3 g/sq cm residual atmosphere. A least-squares fit to the flight data yields an electron spectrum from 8 to 80 GeV of approximately 93E to the -2.91 power electrons/sq m/sec per sr/GeV. The results are compared with those of previous experiments as well as with the spectrum obtained for galactic nonthermal radiation. It is concluded that a 'clumpy' magnetic field proportional to the square root of matter density is consistent with measurements of high-energy electrons and synchrotron radiation toward the center of the Galaxy, that a gradual steepening of the electron spectrum relative to the proton spectrum is consistent with an electron lifetime of 1 million years, and that the density of cosmic-ray nucleons and electrons should be essentially uniform throughout the Galaxy if the nucleons have the same lifetime as the electrons and if they traversed 4 to 5 g/sq cm in that lifetime.

Freier, P.↗
NASA NTRS1975

An observation of the high charge cosmic ray nuclei

A double scintillator - double Cerenkov particle telescope, was used to study cosmic ray nuclei with Z greater than 14. This telescope had an exposure of 17,000 sq m-sr-sec and, consequently, the results obtained were of considerable statistical weight. Data are presented on the charge spectrum and on the energy spectrum over the sensitivity range of the Cerenkov detector. The data are compared with data available in the literature, and the implications are discussed.

Scarlett, W. R.↗
NASA NTRS1975

Intensity of primary electrons above 10 GeV

A nuclear emulsion-spark chamber-counter electron telescope has been flown on a balloon at 3.5 g/sq cm residual pressure over Palestine, Texas, where the vertical cutoff is 4.5 GeV. The spark chamber pictures permitted the elimination of about 50% of the events whose counter signatures alone would qualify them as electrons. Of those events identified as 'electron-like' by counters and spark chambers, only 43% turn out to be electrons when found in the emulsion. The resulting intensities are among the lowest currently reported and are in good agreement with earlier results. The differential intensity in the region 8-40 GeV is measured.

Freier, P.↗
NASA NTRS1975

A chart of cosmic ray isotopes

A chart has been prepared that lists some of the properties relevant to cosmic ray studies of all the significant nuclides between lithium and nickel. On this chart there are shown all the possible decays that might be of interest in the unique conditions experienced by cosmic ray nuclei, various abundance figures and the probable nucleosynthesis processes of origin.

Waddington, C. J.↗
NASA NTRS1975

The detection of high charge cosmic ray nuclei

A large-area, light-weight electronic particle telescope was flown on a high altitude balloon in the summer of 1974 to study the heavy nuclei in the cosmic radiation. This telescope consisted of a double Cerenkov-double scintillator array composed of four 1.22 m diameter disk radiators mounted in light diffusion boxes, each looked at by multiple photomultipliers. The impact point of each particle on the scintillation radiators was determined by studying the relative signals observed by three equally spaced peripheral photomultipliers and one mounted at the center of the diffusion boxes. This telescope was flown in a configuration having a geometric factor of 0.45 sq m sr and observed some 5 x 10 to the 4 nuclei with Z exceeding 14 in a 11 hr exposure. The response and sensitivity of this telescope are discussed in detail.

Scarlett, W. R.↗
NASA NTRS1975

Detection of the isotopes of heavy cosmic ray nuclei

A counter telescope designed to detect and resolve the isotopic composition of cosmic ray nuclei heavier than neon is being prepared. The telescope consists of a rather conventional charge measuring array using two scintillator elements and two solid Cerenkov radiators of differing refractive index. The mass measurement is obtained by combining the velocity information from one or both of the Cerenkov radiators operating near their threshold with residual range measured in a block of nuclear emulsion. Path length corrections and particle location in the emulsions is provided by a spark chamber fired in coincidence with potentially suitable particles. The telescope has a geometry factor of 530 sq cm sr roughly. It should be able to resolve the isotopes of iron over the energy range of 300 to 720 Mev/n and those of neon over 300 to 400 MeV/n. The expected response and characteristics of the telescope are described in detail and the sensitivity to rare isotopes discussed.

Gilman, C. M.↗
NASA NTRS1973

Gamma-ray emission from the region of the Galactic center.

A combination nuclear-emulsion-spark-chamber gamma-ray telescope has been used to study the region of sky that includes the Galactic center. Ninety-five per cent confidence upper limits on the flux from the reported sources G-gamma 2+3 and Sgr gamma-1 were placed at .000044 and .000088 photons per sq cm per sec, and a similar limit on the emission from the Galactic center as a point source was placed at .000033 photons per sq cm per sec. No enhanced emission was observed from the Galactic plane. Three regions of enhanced emission were observed that had a combined Poisson probability of occurrence of less than .005. One of these is associated with a region of enhanced emission reported by other workers.

Dahlbacka, G. H.↗
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.↗