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At least 1,243 records · Page 69
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NASA NTRS1985

A cosmic ray super high energy multicore family event. 2: Structure and fragmentation characteristics of the jets

Quarks and gluons are not directly observable, but may be displayed through fragmentation in the form of hadronic jets, the evidence of which was first revealed in cosmic ray interactions before the advent of the modern theory of strong interactions. Experimental results from ISR and SPPS collider rendered the jet phenomena more confident and definite. All the properties of jets observed up to now at ISR and SPPS collider are in agreement with the predictions of QCD. In order to make further test of QCD in still higher energy regions, detailed study of super high energy jet events in cosmic rays is very desirable. The event KO E19 observed in the Mt. Kambala emulsion chamber is an interesting event for such study. The general features of KO E19 is described. Its total visible energy is sigma E sub gamma = 1537 TeV(E sub min = 1.5 TeV) and production height H=(70 + or - 30)m, with a hadron as its primary particle. Besides about forty small clusters, there are five super high energy cores or jets, one lying near the center of the event while the other four surrounding it, having incident directions making small angles with that of the primary particle. Detailed analysis is done on the emulsion plates inserted in the chamber, making full use of their fine granularity, superior in detecting and analyzing jet events, specially their substructures.

Source record↗
NASA NTRS1985

Samarkand complex setup for investigation of cosmic ray variation in the energy range of 7 10 (9) - 10 (15) eV

The Samarkand complex setup is aimed at the study of cosmic ray variations in a wide energy range from 7 billion eV (which corresponds to the geomagnetic threshold in the region of Samarkand) up to approx 10 to the 15th power to 10 to the 16th power eV. The setup consists of four 6-counter sections of neutron supermonitor with counters SNM-15 and 48 scintillator detectors (1 sq m each) placed under and above the supermonitor. The effective area of the setup for recording neutrons and muons is 24 sq m. The setup can register time variations of the following cosmic ray components: (1) the total neutron counting rate, (2) counting rates for neutrons of different multiplicity, (3) soft-muon fluxes, (4) hard-muon fluxes at various zenith and azimuth angles, (5) electron-photon component, (6) extensive air showers (EAS) induced by primary particles in a wide energy range and accompanied or not accompanied by muons and neutrons.

Dorman, L. I.↗
NASA NTRS1985

A large area cosmic muon detector located at Ohya stone mine

The chemical composition of the primary cosmic rays between 10 to the 15th power eV and 10 to the 18th power eV were determined by a Large Area Cosmic Muon Detector located at Ohya stone mine. The experimental aims of Ohya project are; (1) search for the ultra high-energy gamma-rays; (2) search for the GUT monopole created by Big Bang; and (3) search for the muon bundle. A large number of muon chambers were installed at the shallow underground near Nikko (approx. 100 Km north of Tokyo, situated at Ohya-town, Utsunomiya-city). At the surface of the mine, very fast 100 channel scintillation counters were equipped in order to measure the direction of air showers. These air shower arrays were operated at the same time, together with the underground muon chamber.

Nii, N.↗
NASA NTRS1985

The Nagoya cosmic-ray muon spectrometer 3, part 1: Preliminary observations

There are some discrepancies among the data of absolute muon intensities at large zenth angles. Through the analysis of the data obtained in the previous measurement by Nagoya Cosmic Ray Spectrometer, one of the sources of these discrepancies has been found to be the ambiguity induced by the selection criteria with which genuine muons are distinguished from the backgrounds. To remove the ambiguity of this kind, it is necessary to know the amount of the backgrounds and their characteristics in detail. Some features of the background events were reported from the observations by using this triggering system of Nagoya Cosmic Ray Spectrometer. In this paper, the results of extended observations using track detector together with this system are reported.

Kamiya, Y.↗
NASA NTRS1985

Limits on deeply penetrating particles in the 10(17) eV cosmic ray flux

Deeply penetrating particles in the 10 to the 17th power eV cosmic ray flux were investigated. No such events were found in 8.2 x 10 to the 6th power sec of running time. Limits were set on the following: quark-matter in the primary cosmic ray flux; long-lived, weakly interacting particles produced in p-air collisions; the astrophysical neutrino flux. In particular, the neutrino flux limit at 10 to the 17th power eV implies that z, the red shift of maximum activity is 10 in the model of Hill and Schramm.

Baltrusaitis, R. M.↗
NASA NTRS1985

Monopole, astrophysics and cosmic ray observatory at Gran Sasso

A new large area detector, MACRO was approved for installation at the Gran Sasso Laboratory in Italy. The detector will be dedicated to the study of naturally penetrating radiation deep underground. It is designed with the general philosophy of covering the largest possible area with a detector having both sufficient built-in redundancy and use of complementary techniques to study very rare phenomena. The detector capabilities will include monopole investigations significantly below the Parker bound; astrophysics studies of very high energy gamma ray and neutrino point sources; cosmic ray measurements of single and multimuons; and the general observation of rare new forms of matter in the cosmic rays.

Demarzo, C.↗
NASA NTRS1985

Charge 4/3 leptons in cosmic rays

A cosmic ray counter telescope has been operated at zenith angles of 0, 40, 44, and 60 degs in order to look for charge 4/3 particles. A few million clean single cosmic rays of each zenith angle are analyzed.

Wada, T.↗
NASA NTRS1985

Exploring results of the possibility on detecting cosmic ray particles by acoustic way

It has been demonstrated experimentally and theoretically that high energy particles produce detectable sounds in water. However, no one has been able to detect an acoustic signal generated by a high energy cosmic ray particle in water. Results show that transient ultrasonic signals in a large lake or reservoir are fairly complex and that the transient signals under water may arise mainly from sound radiation from microbubbles. This field is not explored in detail. Perhaps, the sounds created by cosmic ray particles hide in these ultrasonic signals. In order to develop the technique of acoustic detection, it is most important to make a thorough investigation of these ultrasonic signals in water.

Jiang, Y.↗
NASA NTRS1984

Production of high-energy gamma rays by cosmic ray interactions in the atmosphere and lunar surface

The production of gamma rays above 10 MeV by the interaction of cosmic rays in the atmosphere and the lunar surface is simulated using Monte Carlo methods. The calculation incorporates a new model of high-energy nucleon-nucleus interactions based on empirical fits to inclusive cross sections for the production of pions and nucleons. The atmospheric gamma ray flux is calculated as a function of direction, energy, and atmospheric depth. These calculations are compared with observations from balloons and from the SAS 2 satellite. Estimates of the flux of earth albedo electrons produced by cosmic ray interactions are presented. The lunar gamma ray albedo is calculated and compared with an upper limit based on SAS 2 measurements.

Morris, D. J.↗
NASA NTRS1984

Propagation of heavy cosmic-ray nuclei

Techniques for modeling the propagation of heavy cosmic-ray nuclei, and the required atomic and nuclear data, are assembled in this paper. Emphasis is on understanding nuclear composition in the charge range Z = 3-83. Details of the application of 'matrix methods' above a few hundred MeV/nucleon, a new treatment of electron capture decay, and a new table of cosmic ray-stable isotopes are presented. Computation of nuclear fragmentation cross sections, stopping power, and electron stripping and attachment are briefly reviewed.

Letaw, J. R.↗
NASA NTRS1983

Evidence for an energy dependence in the short pathlengths of the cosmic ray pathlength distribution

The energy dependence of the short pathlengths in the cosmic ray pathlength distribution is investigated in a galactic propagation plus solar modulation calculation. In order to reproduce, simultaneously, the compiled B/C and sub-Fe/Fe measurements, an energy dependent deficiency of short pathlengths is required which is largest at low energies and becomes negligible above a few GeV/nucleon. Such behavior could imply a significant contribution from matter in the vicinity of the cosmic ray source or the acceleration site.

Garcia-Munoz, M.↗
NASA NTRS1983

Radial gradients of galactic cosmic rays measured by Pioneer 10 from 1-29 AU through the period of solar maximum

During the approach to maximum solar modulation in 1982, the radial gradient of high energy galactic cosmic rays gradually increased to about 2.5 percent/AU from the solar minimum value of about 1.5 percent/AU. In the same period, at energies lower than 70 MeV/n, the radial gradients for protons decreased from about 8 percent/AU to about 1 percent/AU. It is found that at solar maximum, in contrast to solar minimum, essentially all of the modulation of low energy cosmic rays occurs outside R = 29 AU. The combined effects of solar flare shocks coalescing in the far outer heliosphere may account for this dramatic change in the radial dependence of modulation.

Mckibben, R. B.↗
NASA NTRS1983

Cerenkov detectors for cosmic ray telescopes employing the Cerenkov x total energy technique of mass identification

Considerable progress has been made regarding the evolution of the 'Cerenkov x total energy technique' for mass identification of cosmic ray nuclei since the introduction of telescopes employing this technique by Webber et al. (1973). Thus, significant improvements in mass resolution have been made. These improvements are mainly related to the resolution of the Cerenkov counter. The present investigation is, therefore, concerned with the properties of various types of Cerenkov detectors. In addition, a description is provided of the characteristics of a large area (approximately 0.5 sq m-ster) cosmic ray isotope telescope, which is being developed for use on balloons or spacecraft.

Webber, W. R.↗
NASA NTRS1983

Studies of low energy cosmic rays - The anomalous component

Data from the cosmic ray subsystem on the Voyager spacecraft is used to measure the spectra of He, C, N, O, and Ne with about 4-124 MeV/nuc (for O) near 1 AU. By subtracting both a low-energy solar/interplanetary component and the high-energy galactic component the energy spectra of the anomalous cosmic-ray species He, N, O, and Ne have been determined. It is suggested that the shapes of these spectra carry information about the charge state of the particles and the rigidity dependence of the diffusion coefficient. For similar power-law source spectra at the boundary of the modulation region, the location of features in the energy spectra indicates that the anomalous particles are singly ionized.

Webber, W. R.↗
NASA NTRS1983

Cosmic-ray abundances of the even charge elements from Sn-50 to Ce-58 measured on HEAO-3

Elements with even atomic number (Z) in the interval Z = 50-58 have been resolved in the cosmic radiation using the Heavy Nuclei Experiment on the HEAO-3 satellite. The observation that Sn-50 and Ba-56 are more abundant than Te-52 and Xe-54 indicates a substantial s-process contribution to the cosmic ray source. A significant abundance of Ce-58 provides further support for this finding.

Stone, E. C.↗
NASA NTRS1983

Energy spectra of ultraheavy cosmic rays - Results from HEAO-3

The HEAO-3 Heavy Nuclei Experiment measures cosmic-ray energy directly in the interval 400 to about 1200 MeV/amu. Geomagnetic cutoffs can also be derived up to about 15 GV. Preliminary rigidity spectra of various ultraheavy cosmic-ray elements relative to iron are presented.

Israel, M. H.↗
NASA NTRS1983

The abundance of the radioactive isotope Al-26 in galactic cosmic rays

Satellite observations of the isotopic composition of aluminum in low energy cosmic rays (E/M = 200 MeV/amu) have been used to determine the abundance of the unstable isotope Al-26 (T1/2 = 0.87 Myr). The observed abundance ratio, Al-26/Al-27 = 0.036 (+0.037, -0.022), is in good agreement with previous balloon observations and yields a cosmic ray confinement time consistent with values based on the abundance of Be-10.

Wiedenbeck, M. E.↗
NASA NTRS1983

Upper limit to antiproton flux in cosmic radiation above 100 GeV using muon charge ratio

Upper limits to the fraction of antiprotons in cosmic radiation have been estimated from the observed charge ratio of muons at sea-level. Using these values, it is shown that constraints can be set on the extragalactic hypothesis of the observed antiprotons in the framework of energy-dependent confinement of cosmic rays in the galaxy.

Stephens, S. A.↗