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At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

DUMAND Summer Workshop, University of California, La Jolla, Calif., July 24-September 2, 1978, Proceedings. Volume 1 - Array studies

Papers are presented concerning the design and implementation of the optical and acoustic sensors that will comprise the DUMAND (Deep Underwater Muon and Neutrino Detector) array. Specific topics include the results of experiments on atmospheric muon and neutrino spectra obtained with various muon and neutrino spectrometers, optical sensors and arrays, optical data handling systems, the simulation of the sound generated by high-energy particles in water, constraints on acoustic arrays, standard ocean parameters for DUMAND calculations, and Monte Carlo investigations of hadronic and electromagnetic cascades in sea water.

Roberts, A.↗
NASA NTRS1979

Signal-to-noise ratio for acoustic detection in the deep ocean

A simple method is presented for studying the thermoacoustic wave generated by a heat pulse. The signal-to-noise ratio (S/N) is then calculated for a typical hadronic-electromagnetic cascade in the deep ocean where low frequencies are masked by surface noise. It is found that a maximum useful range of about 16 km is found for typical conditions at 5 km depth. It is shown that in order to obtain useful signals with S/N greater than 100 at distances of 1 to 16 km, the cascade energy must be 10 to the 16th to 10 to the 18th eV. Finally, attention is given to further refinements of the theory of acoustic detection which remain to be investigated.

Bowen, T.↗
NASA NTRS1979

DUMAND Summer Workshop, University of California, La Jolla, Calif., July 24-September 2, 1978, Proceedings. Volume 3 - Oceanographic and ocean engineering studies

The DUMAND (Deep Underwater Muon and Neutrino Detector) array, a hexagon 800 m on a side, 673 m high, and consisting of 22,698 sensor modules, is designed to detect neutrinos in the TeV range, hadronic cascades, muons and Cerenkov radiation. Its engineering, signal processing, and logistic aspects are considered, as are its optical detection (photomultiplier tubes) system and electronics. Geological and bottom current surveys were made at two proposed sites for the array (the Maui and Keahole Point basins of Hawaii), and a study of the steady-state response of a sensor string to current drag forces is reported. Biological interference with the DUMAND array, including mechanical entanglement by large animals, bioluminescence, and especially biofouling are considered, as well as the deployment, implantment and maintenance of the array.

Wilkins, G.↗
NASA NTRS1981

Japanese-American Cooperative Emulsion Experiment /JACEE/

The instrumentation and results of long duration balloon flights carried out jointly by U.S. and Japan researchers to examine high energy cosmic rays are reported. Basic detector geometries are 2.5 sq m sr with operation at altitudes with 3-4 g/sq cm pressure, with observations thus far of over 100 hr. Energies from 2-100 TeV are recorded for nucleus-nucleus and hadron-nucleus interactions, and searches are made for new particle or interactions. The detector is an emulsion chamber which comprises doubly-coated nuclear emulsions on 800 micron thick methacryl substrates, X-ray films, etchable detectors, low density spacers, and lead sheets. Segmentation of the instrument into a primary charge module, a target section, a spacer section, and a lead-emulsion calorimeter allows accurate charge measurement for primary nuclei, reliable energy resolution, and a large geometrical factor for collecting high energy events. A primary Ca nucleus of 300 TeV has been observed.

Huggett, R. W.↗
NASA NTRS1981

Nuclear and particle physics in the early universe

Basic principles and implications of Big Bang cosmology are reviewed, noting the physical evidence of a previous universe temperature of 10,000 K and theoretical arguments such as grand unification decoupling indicating a primal temperature of 10 to the 15th eV. The Planck time of 10 to the -43rd sec after the Big Bang is set as the limit before which gravity was quantized and nothing is known. Gauge theories of elementary particle physics are reviewed for successful predictions of similarity in weak and electromagnetic interactions and quantum chromodynamic predictions for strong interactions. The large number of photons in the universe relative to the baryons is considered and the grand unified theories are cited as showing the existence of baryon nonconservation as an explanation. Further attention is given to quark-hadron phase transition, the decoupling for the weak interaction and relic neutrinos, and Big Bang nucleosynthesis.

Schramm, D. N.↗
NASA NTRS1985

The composition of cosmic rays near the Bend (10 to the 15th power eV) from a study of muons in air showers at sea level

The distribution of muons near shower cores was studied at sea level at Fermilab using the E594 neutrino detector to sample the muon with E testing 3 GeV. These data are compared with detailed Monte Carlo simulations to derive conclusions about the composition of cosmic rays near the bend in the all particle spectrum. Monte Carlo simulations generating extensive air showers (EAS) with primary energy in excess of 50 TeV are described. Each shower record contains details of the electron lateral distribution and the muon and hadron lateral distributions as a function of energy, at the observation level of 100g/cm. The number of detected electrons and muons in each case was determined by a Poisson fluctuation of the number incident. The resultant predicted distribution of muons, electrons, the rate events are compared to those observed. Preliminary results on the rate favor a heavy primary dominated cosmic ray spectrum in energy range 50 to 1000 TeV.

Goodman, J. A.↗
NASA NTRS1985

Cerenkov light images of EAS produced by primary gamma

It is shown that it should be possible to distinguish very effectively between background hadronic showers and TeV gamma ray showers from a point source on the basis of the width, length and orientation of the Cerenkov light images of the shower, seen in the focal plane of a focusing mirror, even with a relatively coarse pixel size such as employed in the Mt. Hopkins detector. Predictions of the response of this system to air showers are presented.

Hillas, A. M.↗
NASA NTRS1985

Neutrino production from the solar atmosphere

When the high energy primary cosmic rays enter near the solar surface, they pass through a thick matter but having a low density. If the density and path length satisfy an appropriate condition, the primaries collide with the constituents near the solar sphere (almost protons) and produce pions and kaons, most of which decay into mu plus nu sub mu without successive hadron collisions. Muons also decay into NU sub mu and NU sub e before reaching the Earth. The neutrino flux of which the producer is matter near the solar surface is computed by solving cascade diffusion equations. The calculated differential flux of muon neutrino at 1 TeV is 1 X 10 to the minus 13 power (GeV. cm square centimeters 2.s.ster)(-1) which is rather difficult to be observed in the present apparatuses or DUMAND.

Inazawa, H.↗
NASA NTRS1985

Nineteenth International Cosmic Ray Conference. HE Sessions, Volume 6

Papers contributed to the 19th International Cosmic Ray Conference which address high energy interactions and related phenomena are compiled. Particular topic areas include cross sections; particle production; nuclei and nuclear matter; nucleus-nucleus collisions; gamma ray and hadron spectra; C-jets, a-jets, and super families; and emulsion chamber simulations.

Jones, F. C.↗
NASA NTRS1985

The method for the study of the inelastic cross-section for high energy protons by means of shower arrays with the large calorimetric area

Proton initiated showers could be reliably separated from showers initiated by cosmic ray nuclei by means of arrays with large calorimetric area, using distributions of energy fractions for EAS electromagnetic muon and hadron components. Proton initiated showers penetrate deeper into the atmosphere and have relatively lower energy fraction in muons. Distribution of that energy fraction is sensitive to the value of the proton inelastic cross-section. It is shown that the analysis of this distribution let one distinguish between log sup 2 S -rise and log S -rise of the cross-section at energies above 10 to the 15th power eV.

Danilova, T. V.↗
NASA NTRS1985

On a possibility of inelasticity partial coefficient K sub gamma determination in pi C and pi Pb interactions at 10 to the 14th power eV (experiment PAMIR 1)

The investigation of hadron-nuclear interactions in Pamir experiment is carried out by means of X-ray emulsion chambers of two types: carbon (C) and lead (Pb). While comparing the results from the chambers of both types it was found a discrepancy in n sub h and E sub h(1)R values. The observed discrepancy in C and Pb chambers is connected with the difference in values of effective coefficients of energy transfer to the soft component K sub eff for C and Pb chambers.

Borisov, A. S.↗
NASA NTRS1985

Multiplicity distributions in interaction models used for cascade simulations

In cascade simulations, conservation of energy is of paramount importance. It is pointed out that it is possible to construct algorithms in which energies of secondaries are chosen from physically correct distributions in such a way as to conserve energy, and give physically correct multiplicity distributions without further adjustment. The resulting non-Poissonian nature of the distribution and the approximate KNO scaling are related to the large fluctuations in the energy available for pion production and to the detailed shape of the inclusive momentum distribution. Two multiparticle production algorithms are described which have these features. One is the algorithm used in the simulation of C jets, the other is for a hadron-nucleus interaction model used in the calculation of muon and neutrino fluxes.

Ellsworth, R. W.↗
NASA NTRS1985

Nucleon-nucleus interactions from JACEE

Results on hadron-nucleus interactions from the Japanese-American Cooperation Emulsion Experiment experiment are presented. Angular distributions for charged particles, and angular and transverse momentum spectra for photons have been measured for a sample of events with sigma epsilon sub gamma. Results on central rapidity density and transverse energy flow are discussed.

Burnett, T. H.↗
NASA NTRS1985

General consequences of the violated Feynman scaling

The problem of scaling of the hadronic production cross sections represents an outstanding question in high energy physics especially for interpretation of cosmic ray data. A comprehensive analysis of the accelerator data leads to the conclusion of the existence of breaked Feynman scaling. It was proposed that the Lorentz invariant inclusive cross sections for secondaries of a given type approaches constant in respect to a breaked scaling variable x sub s. Thus, the differential cross sections measured in accelerator energy can be extrapolated to higher cosmic ray energies. This assumption leads to some important consequences. The distribution of secondary multiplicity that follows from the violated Feynman scaling using a similar method of Koba et al is discussed.

Kamberov, G.↗
NASA NTRS1985

Scaling violation in the fragmentation region of inclusive nucleon spektrum

Spectra of cosmic ray showers associated with hadrons of various energies from 5 to 80 TeV were investigated. Results could be interpreted as scaling violation in the fragmentation region of secondary particles generated in inelastic interactions of primary protons at the energy above 30 TeV.

Machavariani, S. K.↗
NASA NTRS1985

Heavy flavours production in quark-gluon plasma formed in high energy nuclear reactions

Results on compression and temperatures of nuclear fireballs and on relative yield of strange and charmed hadrons are given . The results show that temperatures above 300 MeV and large compressions are unlikely achieved in average heavy ion collision. In consequence, thermal production of charm is low. Strange particle production is, however, substantial and indicates clear temperature - threshold behavior.

Kloskinski, J.↗