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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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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

An underground cosmic ray muon telescope for observation of cosmic ray anisotropy

A telescope housed in a tunnel laboratory has an overburden of 573 hg cm(-2) and is located under the center of a saddle-shaped landscape. It is composed of triple layers of proportional counters, each layer of area approx. 4m x 2m and their separation 0.5m. Events are selected by triple coincidence and software track identification. The telescope is in operation for over a year and the overall count rate is 1280 hr(-1). The structure and operation of the system is reported.

Lee, Y. W.↗
NASA NTRS1985

Energy spectrum of cascade showers induced by cosmic ray muons in the range from 50 GeV to 5 TeV

The energy spectrum of cascade showers induced by electromagnetic interactions of high energy muons of horizontal cosmic ray flux in iron absorber was measured. The total observation time exceeded 22,000 hours. Both the energy spectrum and angular distributions of cascade showers are fairly described in terms of the usual muon generation processes, with a single power index of the parent meson spectrum over the muon energy range from 150 GeV to 5 TeV.

Ashitkov, V. D.↗
NASA NTRS1971

The stopping rate of negative cosmic-ray muons near sea level

A production rate of 0.065 + or - 0.003 Ar-37 atom/kg min of K-39 at 2-mwe depth below sea level was measured by sweeping argon from potassium solutions. This rate is unaffected by surrounding the solution by paraffin and is attributed to negative muon captures and the electromagnetic interaction of fast muons, and not to nucleonic cosmic ray component. The Ar-37 yield from K-39 by the stopping of negative muons in a muon beam of a synchrocyclotron was measured to be 8.5 + or - 1.7%. The stopping rate of negative cosmic ray muons at 2-mwe depth below sea level from these measurements and an estimated 17% electromagnetic production is 0.63 + or - 0.13 muon(-)/kg min. Previous measurements on the muon stopping rate vary by a factor of 5. Our value is slightly higher but is consistent with two previous high values. The sensitivity of the Ar-37 radiochemical method for the detection of muons is considerably higher than that of the previous radiochemical methods and could be used to measure the negative muon capture rates at greater depths.

Spannagel, G.↗
NASA NTRS1985

The Nagoya cosmic-ray muon spectrometer 3, part 2: Track detector

The twelve wide gap spark chambers were utilized as the track detectors of the Nagoya cosmic-ray muon spectrometer not only to obtain the precise locations of particles, but also to get some information about the correspondences between segments of trajectories. The area of each chamber is 150 x 70 sq cm and the width of a gap is 5 cm. The gas used is He at the atmospheric pressure. Each three pairs of them are placed on both sides of the deflection magnet. All images of sparks for each event are projected through the mirror system and recorded by two cameras stereoscopically. The mean detection efficiency of each chamber is 95 + or - 2% and the spacial resolution (jitter and drift) obtained from the prototype-experiment is 0.12 mm. Maximum detectable momentum of the spectrometer is estimated at about 10 TeV/c taking into account these characteristics together with the effects of the energy loss and multiple Coulomb scattering of muons in the iron magnet.

Shibata, S.↗
NASA NTRS1985

The Nagoya cosmic-ray muon spectrometer 3, part 4: Track reconstruction method

One of the greatest problems in measuring particle trajectories with an optical or visual detector system, is the reconstruction of trajectories in real space from their recorded images. In the Nagoya cosmic-ray muon spectrometer, muon tracks are detected by wide gap spark chambers and their images are recorded on the photographic film through an optical system of 10 mirrors and two cameras. For the spatial reconstruction, 42 parameters of the optical system should be known to determine the configuration of this system. It is almost impossible to measure this many parameters directly with usual techniques. In order to solve this problem, the inverse transformation method was applied. In this method, all the optical parameters are determined from the locations of fiducial marks in real space and the locations of their images on the photographic film by the non-linear least square fitting.

Shibata, S.↗
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 NTRS1972

Stopping rate of negative cosmic-ray muons near sea level.

A relatively simple method for measuring with high sensitivity the rate of stopped negative muons is described. A process in which Ar-37 is obtained from K-39 in connection with the stopping of a negative muon was used in the experiments. The Ar-37 activity can be measured in small proportional counters with extremely low backgrounds. It is possible to remove Ar-37 from potassium acetate powder at room temperature with almost 100 per cent efficiency merely by trapping the gas from the storage container with a charcoal trap at the liquid nitrogen temperature.

Spannagel, G.↗
NASA NTRS1985

Observation of an excess of cosmic ray muons of energies 2 TeV from the direction of Cygnus X-3

A high flux of muons from the Cygnus X-3 direction has been observed in NUSEX experiment at depths greater than 4600 hg/sq cm s.r. The excess muons show the 4.8 hour modulation in arrival time typical of this source. A study of this modulation was done in order to find the best value of the period and of the period derivative. The muon flux underground from NUSEX and SOUDAN (1800 hg/sq cm) experiments are used to determine the energy spectrum at sea level. The shape and the absolute intensities are found similar to those attributed to gamma rays responsible for production of air showers detected in direction of Cygnus X-3 in the energy range 10 to the 12th power to 10 to the 15th power eV.

Battistoni, G.↗
NASA NTRS1993

Absolute spectrum and charge ratio of cosmic ray muons in the energy region from 0.2 GeV to 100 GeV at 600 m above sea level

We have determined the momentum spectrum and charge ratio of muons in the region from 250 MeV/c to 100 GeV/c using a superconducting magnetic spectrometer. The absolute differential spectrum of muons obtained in this experiment at 600 m above sea level is in good agreement with the previous measurements at sea level. The differential spectrum can be represented by a power law with a varying index, which is consistent with zero below 450 MeV/c and steepens to a value of -2.7 +/- 0.1 between 20 and 100 GeV/c. The integral f1ux of muons measured in this experiment span a very large range of momentum and is in excellent agreement with the earlier results. The positive to negative muon ratio appears to be constant in the entire momentum range covered in this experiment within the errors and the mean value is 1.220 +/- 0.044. The absolute momentum spectrum and the charge ratio measured in this experiment are also consistent with the theoretical expectations. This is the only experiment which covers a wide range of nearly three decades in momentum from a very low momentum.

De Pascale, M. P.↗
NASA NTRS1985

Results of investigation of muon fluxes of superhigh energy cosmic rays with X-ray emulsion chambers

The overall data from the investigation of the cosmic ray muon flux in the range of zenith angles (0-90) deg within the energy range (3.5 to 5.0) TeV is presented. The exposure of large X-ray emulsion chambers underground was 1200 tons. year. The data were processe using the method which was applied in the experiment Pamir and differred from the earlier applied one. The obtained value of a slope power index of the differential energy spectrum of the global muon flux is =3.7 that corresponds to the slope of the pion generation differential spectrum, gamma sub PI = 2.75 + or - .04. The analysis of the muon zenith-angular distribution showed that the contribution of rapid generation muons in the total muon flux agree the best with the value .2% and less with .7% at a 90% reliability level.

Ivanenko, I. P.↗
NASA NTRS1985

The longitudinal development of muons in cosmic ray air showers at energies 10(15) - 10(17) eV

The relationship between longitudinal development of muons and conventional equi-intensity cuts is carefully investigated. The development of muons in Extensive Air Showers (EAS) has been calculated using simulation with a scaling violation model at the highest energies and mixed primary composition. Profiles of equi-intensity cuts expected at observation altitudes of 550, 690 and 930/sq cm can fit the observed data very well.

Source record↗
NASA NTRS1985

Underwater measurements of muon intensity

Experimental measurements of cosmic ray muon intensity deep underwater aimed at determining a muon absorption curve are of considerable interest, as they allow to reproduce independently the muon energy spectrum at sea level. The comparison of the muon absorption curve in sea water with that in rock makes it possible to determine muon energy losses caused by nuclear interactions. The data available on muon absorption in water and that in rock are not equivalent. Underground measurements are numerous and have been carried out down to the depth of approx. 15km w.e., whereas underwater muon intensity have been measured twice and only down to approx. 3km deep.

V.M. Fedorov↗
NASA NTRS1985

Angular distribution of muons produced by cosmic ray neutrinos in rock

Measurement of the upgoing muons flux, produced by cosmic ray neutrinos is aiming at: (1) search for neutrino oscillation; (2); search for extraterrestrial neutrinos from local sources; and (3); search for any hypothetical neutral penetrating radiation different from neutrinos. Experimental data of the Baksan underground telescope on intensity of upward muons for three years of living time, was analyzed having in mind mainly neutrino oscillation.

Boliev, M. M.↗
NASA NTRS1985

Atmospheric muons and neutrinos, and the neutrino-induced muon flux underground

The diffusion equation for neutrino-induced cosmic ray muons underground was solved. The neutrino-induced muon flux and charge ratio underground have been calculated. The calculated horizontal neutrino-induced muon flux in the energy range 0.1 - 10000 GeV is in agreement with the measured horizontal flux. The calculated vertical flux above 2 GeV is in agreement with the measured vertical flux. The average charge ratio of neutrino-induced muons underground was found to be mu+/mu- = 0.40.

Liland, A.↗
NASA NTRS1985

Energy spectrum of cascades generated by muons in Baksan underground scintillation telescope

Spectrum of cascades generated by cosmic ray muons underground is presented. The mean zenith angle of the muon arrival is theta=35 deg the depth approx. 1000 hg/sq cm. In cascades energy range 700 GeV the measured spectrum is in agreement with the sea-level integral muon spectrum index gamma=3.0. Some decrease of this exponent has been found in the range 4000 Gev.

Bakatanov, V. N.↗