bluuebunny/crossref_metadata_2025 huggingface dataset:
Antennas, receivers, and problems of the radio detection of large air showers
Authors: Jelley J. V.
Published: April 2011

The paper reviews the basic requirements for the passive detection of large air showers by radio methods. After a general introduction, a discussion of the factors which influence the choice of frequency and bandwidth follows, and a brief survey is presented of the characteristics of various types of antenna suitable for this field of work. A more detailed discussion of the all important problems of interference, with comments on its recognition and its suppression, is also given. A few remarks are included on receiver design and some associated problems, notably AGC, and the paper closes with brief comments on the choice of suitable sites for work in this field.
Experimental tests of the mechanism of radio emission from showers
Authors: Smith F. G. , Bray A. D. , Porter R. A. , Torbitt W. S. , Jelley J. V.
Published: April 2011

It is expected that the geomagnetic field will separate the shower particles of opposite signs, giving radiation which shows an east–west polarization. This has been tested by using crossed dipoles, and by searching for the expected asymmetry in the north–south plane due to the dip angle of the field. No evidence for geomagnetic separation has been found, and it is concluded that the excess charge must be greater than had previously been assumed.
Radio pulses from air showers at Mt. Chacaltaya
Authors: Barker P. R. , Hazen W. E. , Hendel A. Z.
Published: April 2011

Pulses from a helical antenna and from a broad-band log-periodic TV antenna were photographed when any of various trigger requirements were met. In order to use arrival directions to correlate radio pulses with air showers, the antennas were pointed away from the zenith. Results for arrival direction correlation are presented. Preliminary evidence that the radio pulse energy increases with decreasing frequency in the region 40–60 MHz is presented. In addition to triggering on air shower particles alone, we also successfully used a coincidence of radio pulses and shower particles as a trigger. Latest preliminary results obtained with the TV antenna indicate that radio pulses may not be polarized perpendicular to the earth's magnetic field.
Tokyo large air shower project
Authors: Matano T. , Nagano M. , Suga K. , Tanahashi G.
Published: April 2011

A preliminary experiment to detect large air showers by means of radio echoes and to study the high-energy end of the primary cosmic-ray energy spectrum has been started at this Institute. The fundamental idea and the first approach of the experiment are presented. Using the telemetry system between two pairs of a simple scintillation array, which has been constructed to identify and calibrate the showers in the above experiment, the decoherence curve of air showers has been measured between 100 and 1 300 m together with the particle density in each detector. This simple experiment will give the power of the size spectrum above 109.
Preliminary results from the Sydney University Giant Air Shower Recorder
Authors: Brownlee R. G. , Fisher A. J. , Goorevich L. , Kohn P.C. , McCusker C. B. A. , Ögelman H. B. , Parkinson A. F. , Peak L. S. , Rathgeber M. H. , Ryan M. J. , Winn M. M.
Published: April 2011

Preliminary results are presented from the Sydney University Giant Air Shower Recorder. A pilot array has been operating since September 1966. Each station consists of two 6-m2 liquid scintillators 2 m underground and separated by 50 m. The pilot array has three stations separated by 455, 595, and 630 m. A coincidence at one station triggers the nearby 64 scintillator and Geiger arrays.Construction of the first 25 stations of the main array began in January 1967. This array is made up of nine stations on a square grid of separation 400 m nesting within nine stations on a square grid of 800 m nesting within a square grid 3.2 × 6.4 km with a 1 600-m spacing. It is hoped to extend this main array to 16 × 16 km. Construction of the next nine stations is scheduled to begin in May 1967.
An imaging system for EAS optical emission
Authors: Bunner A. N. , Greisen K. , Landecker P. B.
Published: April 2011

The Cornell University Cosmic Ray Group is pursuing an experimental attack on the problem of detecting and analyzing ultra-high-energy air showers by the optical emission m the atmosphere. A technique has been developed to record pulses of light from a sequence of adjacent positions in the night sky, by imaging a sector of the sky onto a mosaic of photomultiplier tubes nested in the focal surface of a large Fresnel lens. Sixteen such lens units are then necessary to view a full 2π steradians. It is shown that, in the wavelength region 3 400 to 4 500 Å, Cerenkov radiation dominates the first 23° from the point of appearance of the shower, while nitrogen fluorescence allows tracking of the shower beyond 23°.
The muon density spectrum at large zenith angles
Authors: Alexander D. , Holyoak B. , Thompson M. G. , Turner M. J. L.
Published: April 2011

The frequency of coincident penetrating particles crossing an area 30 m2 at large zenith angles has been measured, and comparison is made with the results of calculations based upon a model of propagation of the EAS through the atmosphere. The experimental results regarding the rate of recording showers as a function of zenith angle do not agree with a mean transverse momentum of secondaries, in high-energy interactions, of 400 MeV/c, but indicate a value of 800 MeV/c. The variation of rate with zenith angle follows a [Formula: see text] law at large zenith angles. The density spectrum of the showers at large zenith angles has also been measured, and for the larger recorded densities this result is in better agreement with the theory incorporating a mean transverse momentum of 400 MeV/c than that incorporating a value of 800 MeV/c.
Energy determination of electromagnetic cascades recorded in nuclear emulsions
Authors: Enge W.
Published: April 2011

Five electromagnetic cascades of energies 835, 820, 300, 160, and 85 GeV were measured in the emulsions of an emulsion–tungsten stack. For small angles the integral angular distributions of the electrons are shown to be functions of the product E0 × θ (GeV × rad), where E0 is the primary energy of the cascades and θ is the angle up to which electrons were accepted. This is analogous to the well-known fact that the integral radial distributions depend on E0 × R (GeV × r.l.) in the core of the cascade, where R is the radius of a circle inside which were electrons.
The high–energy muon flux at sea level up to 10 TeV derived from an observation of the burst-size spectrum
Authors: Chin S. , Hanayama Y. , Hara T. , Higashi S. , Kitamura T. , Miono S. , Miyamoto S. , Nakagawa M. , Ozaki S. , Takahashi T. , Tsuji K. , Watase Y. , Kobayakawa K. , Shibata H.
Published: April 2011

Bursts produced by high-energy muons in rock have been observed at a depth of 40 m.w.e. underground by the use of two layers of scintillator 20 m2 in area and 2 m apart. The size distribution of bursts with several hundreds to 30 000 relativistic particles was obtained during an observing time of 11 424.13 hours. Following the method of Christy and Kusaka (1941), the energy spectrum of muons up to 10 TeV was derived from the burst-size distribution.
The muon spectra near the geomagnetic equator
Authors: Allkofer O. C. , Andresen R. D. , Dau W. D.
Published: April 2011

The vertical momentum spectrum and the charge ratio of cosmic-ray muons have been investigated in the range 0.3–25 GeV/c at a geomagnetic latitude of λ = 9 °N at sea level. The investigations have been performed by means of a magnetic spectrograph using the spark chamber technique for track location. The measured spectrum in the low-energy region is about 20% smaller than the spectra at high geomagnetic latitudes. The integral intensity for particles which penetrate more than 15 cm of lead is 7.25 × 10−3 cm−2 s−1 sr−1. The theoretical spectrum after Olbert is in agreement with our results.
Delayed shower particles at 70 m.w.e. underground
Authors: Dardo M. , Penengo P. , Sitte K.
Published: April 2011

Delayed penetrating shower particles were observed in two experiments at the Mt. Cappuccini station, Torino, 70 m.w.e. underground. In the first the arrival-time differences of pairs and triples were recorded. While for pairs the distribution of delays above 80 ns was essentially consistent with that of the expected accidental traversals, a peak around 80 ns was found for triples. This could indicate that heavy shower particles, if they exist, are present only in high-energy events. In the second experiment a telescope of four scintillators, separated by three layers of lead, was added in order to provide information on the interactions of delayed particles. Again the time distribution shows a statistically significant increase of the frequency of particles arriving within the interval of 40 to 100 ns. But at present the time of operation has been much too short to allow far-reaching conclusions. The total rate of events recorded in the second experiment is still in statistical agreement with—indeed lower than—the expected frequency of accidental traversais.
Investigation of the high-energy penetrating component of cosmic radiation at shallow depths underground with the Tien-Shan ionization calorimeter
Authors: Erlykin A. D. , Kulichenko A. K.
Published: April 2011

With the Tien-Shan (3 340 m altitude) ionization calorimeter, the spectrum of ionization bursts has been investigated at a depth of 20 m.w.e. underground. The results obtained show that the characteristics of the penetrating component do not differ from those expected of the muon component; there is no evidence for the existence of the "baryon-passive" state, which has been suggested by Smorodin.
Electromagnetic interactions of high-energy muons
Authors: Ashton F. , Coats R. B. , Simpson D. A.
Published: April 2011

The nearly horizontal muon flux at sea level has been used to study the interactions of high-energy (34–520 GeV) muons in an iron absorber producing energy transfer in the range 3–240 GeV. No significant divergence from accepted theory has been found.
Muon interactions in the energy range 5 to 1 000 GeV
Authors: Kelly G. N. , MacKeown P. K. , Said S. S. , Wolfendale A. W.
Published: April 2011

The Durham Horizontal Spectrograph has been used to study the variation with energy of the frequency of electromagnetic interactions of muons. A considerable increase in the frequency of occurrence of electromagnetic showers with muon energy is observed and is attributable in the main to direct pair production. The form of the variation with energy of the interaction probabilities and the frequency of successive interactions of the same particle are consistent with all the particles being muons, and it is concluded that there is no evidence in favor of the existence of particles having an unusually high probability of burst production–the X particles postulated by Vernov et al. (1966)–at least in the near-horizontal cosmic-ray beam at ground level.
Horizontal air showers induced by muons with energy above 1013 eV
Authors: Matano T. , Nagano M. , Shibata S. , Suga K. , Tanahashi G. , Kameda T. , Toyoda Y. , Hasegawa H.
Published: April 2011

We have been observing horizontal air showers to study the high-energy interactions of muons. Nine horizontal air showers of size greater than 104 and zenith angle above 70° were observed. Two of these showers showed evidence that they are not pure electromagnetic showers but nucleonic showers. One shower contained a nuclear-active particle which produced a nuclear interaction in the cloud chamber, and the other shower contained a muon which penetrated about 103 g cm−2 of iron absorber. The size distribution of the horizontal showers was compared with the calculated one assuming that the nuclear interaction of high-energy muons was negligible. The discrepancy between the experimental distribution and the calculated one is reduced if the nuclear interaction of high-energy muons is taken into account, which supports our view that the horizontal air showers (at least some fraction of them) are produced by nuclear interactions of high-energy muons.
The photonuclear cross section at high energies as determined from the nuclear interaction of muons
Authors: Hodgson R. J. W. , Murdoch H. S. , Rathgeber H. D.
Published: April 2011

Information about the photonuclear cross section σγ, at high energy can be obtained from muon interaction experiments by considering the virtual photon spectrum of the muons. Previous attempts to fit a virtual photon spectrum and form factor to the following experiments are discussed: (1) interaction of machine-produced muons at 2.5 and 5 GeV; (2) interaction of cosmic-ray muons at high energy; (3) the intensity–depth relation of cosmic-ray muons deep underground. It is shown that previous proposals to fit one or more of these experiments are not consistent with all the experimental evidence, particularly in relation to the form factor. It is demonstrated that σγ is energy-dependent above 1 GeV and, with due allowance for this, a form factor may be found which is consistent with the various experiments.
Study of the nuclear and electromagnetic interactions of high-energy muons
Authors: Borog V. V. , Kirillov-Ugryumov V. G. , Petrukhin A. A. , Shestakov V. V.
Published: April 2011

Cascade showers produced by high-energy cosmic muons at large zenith angles have been studied by means of an ionization calorimeter. The method of separation of electromagnetic and nuclear showers is described. The angular distribution and energy spectrum of the nuclear showers are given. An estimate of the photonuclear cross section at high energy [Formula: see text] is made using both the virtual photon spectrum developed by Weizsäcker and Williams (WW) and the theory of Kessler and Kessler (1957; KK). It is equal to (2.0 ± 1.1) × 10−28 cm2/nucleon for WW and (0.15 ± 0.08) × 10−28 cm2/nucleon for KK. The experimental electromagnetic showers with energy ~1012 eV were compared with the theoretical cascade curves. The experimental and theoretical data are in good agreement if the value of the radiation length in iron is equal to (13.8 ± 0.3) g cm−2.
The muon energy spectrum at sea level from the intensities deep underground
Authors: Kobayakawa K.
Published: April 2011

The energy spectrum of muons at sea level is determined from the intensities deep underground. The following three points are different from past treatments: (1) From the energy-loss relation, −(dE/dt) = k(E) + b(E)E, including the effect of nuclear interaction and without the assumption that b is independent of E, the average range–energy relation is derived. (2) The reliable values of the factor which corrects for fluctuations in energy loss of muons passing through a great thickness of material are used. (3) Many authors measured the intensities under their respective rocks. The differences of these rocks are taken into account in the following way. The intensities are directly converted into the energy spectrum at sea level by using the appropriate average range–energy relations and correction factors. The resultant integral exponent of the energy spectrum in the vertical direction is β = 2.541 ± 0.190 with 95% confidence over the energy range 0.4–7 TeV having a weighted mean of 0.7 TeV.
Gamma-ray astronomy with a digitized spark chamber
Authors: Fichtel C. E. , Cline T. L. , Ehrmann C. H. , Kniffen D. A. , Ross R. W.
Published: April 2011

A series of high-altitude balloon flights designed to look at possible point sources of cosmic gamma radiation have been made beginning in September 1966. The heart of the detector system used in these investigations consists of a 32-level magnetic-core digitized spark chamber, with 256 wires per level and thin (0.02 radiation length) high-Z pair-producing plates between each level. This spark chamber is surrounded by a bell-shaped plastic scintillator dome and is triggered by a coincidence between a thin central scintillator and a Cerenkov counter in anticoincidence with the dome. This device is flown in an oriented balloon gondola. Results related to several potential γ-ray sources have been obtained in a series of three flights. Upper limits for the flux of γ rays above 30 MeV of (2–4) × 10−5 (cm2 s)−1 have been established for Sco X-1, Sgr SR-1, Sgr SR-2, Sgr SR-3, the Kepler Supernovae (Oph XR-1), the galactic center, the moon, and the quiet sun. Somewhat less severe limits have been set for Centaurus A and Taurus A.
Search for cosmic gamma radiation with a vidicon spark chamber
Authors: Fazio G. G. , Helmken H. F. , Cavrak Jr. S. J. , Hearn D. R.
Published: April 2011

A vidicon spark chamber flown in a high-altitude balloon has been used to search for primary gamma radiation (E > 100 MeV). No celestial gamma-ray source was detected. The new upper limit to the flux from the Crab nebula was found to be 3.1 × 10−5 cm−2 s−1, and the flux from the quiet sun to be [Formula: see text]. A solar flare (type 2) also occurred during the flight, of flux [Formula: see text], which is also a new upper limit. The gamma-ray background flux and energy spectrum at 4 g cm−2 altitude were measured.
Observations of cosmic X-ray sources in the 10–250 keV range
Authors: Peterson Laurence E. , Jacobson Allan S. , Pelling R. M. , Schwartz Daniel A.
Published: April 2011

Observations of cosmic X-ray sources have been made from high-altitude balloons over Palestine, Texas, using actively collimated detectors. In this technique, a thin NaI central counter 10 to 50 cm2 in area is surrounded by a CsI well crystal shield several centimeters thick. The aperture, about 8° to 20° FWHM, is determined by either the well opening or an active honeycomb collimator. The background is determined mainly by diffuse cosmic and atmospheric X-rays entering the forward aperture. The detector is usually either servo-controlled to track the source or operated as a meridian device. Data are telemetered over the 20–250 keV range in a digital format from a 128-channel pulse-height analyzer. Several strong sources in the northern hemispheric sky have been observed. The Crab nebula has a power-law differential number spectrum with an index of –1.9 ± 0.1 and an intensity of about 10−2 photons/cm2-s-keV at 20 keV. Two observations in September 1965 and September 1966 on this object give the same flux and spectral index within about 5% over the 20–100 keV range. The source Cygnus XR-1 also has a power-law shape, very similar in slope and intensity to the Crab, which extends above background to at least 180 keV. These measurements are in general agreement with those of other workers. The power-law spectrum of the Crab and Cygnus XR-1 may be contrasted with that of SCO XR-1, which has an exponential spectrum, typical of a hot gas at 50 × 106 °K.
An experiment to search for discrete sources of cosmic gamma rays in the 1011 to 1012 eV region
Authors: Fazio G. G. , Helmken H. F. , Rieke G. H. , Weekes T. C.
Published: April 2011

A large optical reflector, designed to detect the Cerenkov radiation produced in the night sky by cosmic gamma rays, is being built for operation in the spring of 1968. The f/0.7 reflector will have an effective aperture of 34 ft, consisting of a mosaic of 252 2-ft hexagonal mirrors supported on a fully steerable frame. The mirrors will be front-aluminized so that by use of S-13 photocathodes the ultraviolet component of the Cerenkov radiation down to 3 000 Å can be detected. The optical efficiency of the reflector will be such that 75% of the light between 3 000 and 5 000 Å from a point source on the optical axis at infinity will be concentrated into a 2.5-in.-diameter disk in the focal plane. The instrument will be located on the 7 600-ft level of Mount Hopkins, Arizona. The mount for the reflector is so constructed that an additional 34-ft reflector can be added at a later date. With the large-aperture, high-speed electronics (100 Mc s−1 bandwidth), and S-13 optical wave band, the present energy threshold for the detection of gamma rays by the atmospheric Cerenkov light technique will be lowered by at least an order of magnitude. Theoretical models for the Crab nebula based on the inverse Compton effect predict a gamma-ray flux 10 times greater than the minimum flux sensitivity of the instrument. Several other possible sources will also be surveyed.
Application of the vidicon spark chamber to gamma-ray astronomy from high-altitude balloons and satellites
Authors: Fazio G. G. , Helmken H. F.
Published: April 2011

On May 28, 1966, a vidicon spark-chamber detector was successfully flown for 6 hours at an altitude of 125 000 ft from the National Center for Atmospheric Research Balloon Flight Station at Palestine, Texas.Preliminary to the actual flight, extensive helicopter tests of the television telemetry system and thermal vacuum tests of the entire package were performed. Radio-frequency interference (RFI) from the spark discharges necessitated very careful shielding of the chamber from the electronic components.During the flight, while video data were being telemetered and recorded on kinescope film and magnetic tape, a constant visual check was kept on the television monitor to ensure that all systems were operating properly. In-flight solar calibration of an on-board magnetic compass yielded azimuth accuracies of [Formula: see text].Subsequently to the flight, a careful investigation was performed to determine the feasibility of incorporating a vidicon spark chamber into an Explorer-type satellite. Using slow-scan television, a design has been evolved that can satisfy the weight, size, power, and telemetry requirements of an Explorer-type system. With the proper vidicon system, sparks can be located to an accuracy of 0.1% and the resolution of two sparks to 0.5% to 1% of full sweep (1 to 2 mm in a 20-cm × 20-cm chamber). Only spark locations and intensity are stored in an on-board tape recorder and on command are telemetered to a ground station.
Energy spectrum of diffuse primary X rays up to 180 keV
Authors: Bleeker J. A. M. , Burger J. J. , Deerenberg A. J. M. , Scheepmaker A. , Swanenburg B. N. , Tanaka Y. , Hayakawa S. , Makino F. , Ogawa H.
Published: April 2011

Two balloon flights with identical X-ray detectors were carried out in the summer of 1966, one from De Bilt, the Netherlands (geomagnetic latitude 53 °N), and the other from Taiyomura, Japan (geomagnetic latitude 25 °N). The detector consists of a NaI(Tl) crystal, 12.5 mm thick and 50 mm in diameter, surrounded by an effective collimator-shield and a plastic scintillator guard counter. The rotating disk incorporated enables the separation of "forward" X rays from the cosmic-ray-induced background. The results of the flights are in very good agreement with each other. In view of the rather large difference in geomagnetic latitude in these two flights, this agreement supports the celestial origin of the primary X rays observed. The energy spectrum between 20 and 180 keV can be expressed by a power law:[Formula: see text]
Observations of the background component of cosmic X rays
Authors: Matsuoka M. , Oda M. , Ogawara Y. , Hayakawa S. , Kato T.
Published: April 2011

The background component of cosmic X rays was observed using collimators of different fields of view. It was found that there existed a component with the counting rate proportional to the field of view. The intensity of the background component was found to be essentially uniform except in the region including the Sco X-1 source and sources in the vicinity of the galactic center. The energy spectrum was nearly flat in the energy range between 4 and 8 keV, and the intensity was 0.45 ± 0.09 photon cm−2 s−1 keV−1. The shape of the spectrum was checked by comparison with the spectrum of Sco X-1.
X-radiation fields in Cas A and Vir A
Authors: Johnson Hugh M.
Published: April 2011

Recent X-ray detection of the radio and optical sources Cas A (galactic) and Vir A (extra-galactic) provides new ways to relate the continua and line emissions in the spectra. The level of photoionization and the surface brightness of the optical continua are discussed. The apparent detection of part of the optical continuum of Cas A is also discussed.
On the solar neutrino spectrum from the decay 8B(e+ν)8*Be(α)4He
Authors: Kopysov Yu. S. , Kuzmin V. A.
Published: April 2011

The neutrino spectrum from the decay 8B(e+ν)8*Be(α)4He is calculated taking into account the transitions to the 2.9, 16.62, and 16.92 MeV levels of 8Be and the natural widths of the levels as well. The mean absorption cross sections for 8B neutrinos for some solar neutrino detectors are evaluated. Because of the uncertainty in the shape of the experimental α spectrum the 8B-neutrino absorption cross sections cannot be calculated to better than 5%.
On the investigation of the internal structure of the sun by means of neutrino radiation studies
Authors: Dergachov V. A. , Kocharov G. E.
Published: April 2011

We consider the possibilities of investigating the internal structure of the sun using the energy spectrum and the intensity of its neutrino radiation. The experimental determination of the solar neutrino flux will permit us to obtain values for some parameters which are important for the theory of the internal structure of the sun (e.g. the time for evolution and the concentrations of various isotopes in the interior). It is also possible to decide whether or not the gravitational constant varies with time.
Gamma rays in the MeV region at balloon altitude
Authors: Okudaira K. , Hirasima Y.
Published: April 2011

Gamma rays in the MeV region were observed from balloons at λ = 26 °N on September 29, 1966. A scintillation counter constructed with two NaI ⅓ in. × 2 in. [Formula: see text] crystals separated by 1 cm × 2 in. [Formula: see text] lead was used to measure the directional distribution of the gamma-ray flux. This counter was flown at an atmospheric depth of 14.2 g cm−2. As the response of each crystal of this counter depends on the direction of incidence of the gamma rays, an anisotropic distribution of gamma rays gives rise to a difference between the counting rates of two crystals. It was ascertained from the observation that albedo gamma rays from the lower atmosphere are predominant at this high altitude. The deviation from the calculated values of the difference in counting rate assuming only atmospheric gamma rays may be due to an extraterrestrial origin of part of the gamma-ray flux. For the measurement of the gamma-ray spectrum, a phoswich counter (1 in. × 1 in. [Formula: see text] NaI crystal surrounded by ¼-in.-thick plastic scintillator) was flown to 10 g cm−2. Though the main part of the gamma-ray flux is probably due to atmospheric gamma rays, an upper limit for the isotropic cosmic gamma-ray flux is deduced to be (1.25 ± 0.05) × 10−2 counts cm−2 s−1 sr−1 MeV−1 in the energy range 1.2–3.1 MeV.
Measurement and interpretation of the isotopic composition of hydrogen and helium cosmic-ray nuclei below 75 MeV/nucleon
Authors: Meyer J. P. , Hagge Donald E. , McDonald Frank B.
Published: April 2011

The differential energy spectra of the hydrogen and helium isotopes of the galactic cosmic radiation have been measured in 1965 and 1966 by the highly eccentric satellites OGO I and IMP III. The energy ranges were respectively 20–50 and 30–90 MeV/nucleon.The measured ratio Γd = d/4He shows a very steep positive slope [Formula: see text] as a function of energy between 20 and 50 MeV/n. At 50 MeV/n, Γd is roughly 0.25. These results are in qualitative agreement with the measurements performed by the University of Chicago group on IMP III. The measured ratio ΓHe = 3He/4He is roughly 0.05 at 60 MeV/n, and decreases at lower energies.In order to understand the energy dependence of ΓHe and especially of Γd (Γd is not affected by the solar modulation), we investigated the creation of deuterons and 3He through fragmentation of cosmic-ray and interstellar 4He nuclei, and proton–proton reactions (assuming no injection of these isotopes at the source).We have used a Monte Carlo technique to propagate the cosmic-ray protons and 4He nuclei from the source to the earth. A critical survey of the available cross-section data has been made. The ionization loss, the energy dependence of the cross sections, and the reaction kinematics have been taken into account. The elastic scattering, acceleration in space, and solar modulation have not.We have systematically tried to fit the data with different source spectra and propagation models. Our present results completely rule out a total-energy, and favor a kinetic-energy source power spectrum. We discuss the bearing of different nonlocal propagation models (open model, closed model, injection at one time; different energy dependences of the mean "vacuum path-length") on Γd and ΓHe.
The chemical composition of cosmic rays in the energy range 70-240 MeV/nucleon in 1966
Authors: Badhwar G. D. , Deney C. L. , Dennis B. R. , Kaplon M. F.
Published: April 2011

The differential energy spectra of 3He and 4He and upper limits on the primary deuteron flux obtained during the same balloon flights of the double dE/dx vs. E detector described previously (Badhwar et al. 1967a, b) are presented. The results yield an essentially constant ratio 3He/(3He + 4He) with value 0.094 ± 0.017 in the energy range 70–240 MeV/nucleon. An upper limit of 0.25 for the 2H/4He ratio is obtained at 150 MeV/n. Implications of these results in terms of possible path-length distributions will be discussed.
The energy spectrum of primary cosmic rays and the secondary radiation background in the vicinity of the earth
Authors: Bazilevskaya G. A. , Charakhchyan A. N. , Charakhchyan T. N. , Kvashnin A. N. , Pankratov A. K. , Stepanyan A. A.
Published: April 2011

Experimental data on the energy spectrum of the cosmic-ray primary component and total flux of the secondary radiation near the earth are examined. The data have been obtained by extrapolation of the results of regular measurements of the ionizing and photon components of cosmic rays at high altitudes in the stratosphere at various geomagnetic latitudes.
Energy spectrum of primary electrons in the range 0.5-30 GeV
Authors: Bleeker J. A. M. , Burger J. J. , Deerenberg A. J. M. , Scheepmaker A. , Swanenburg B. N. , Tanaka Y.
Published: April 2011

Several balloon observations have been carried out to determine the energy spectrum of primary electrons in the range 0.5–30 GeV. The detectors are standardized for mutual data comparison and calibrated in accelerator beams. The present report summarizes the results of the flights from Kiruna, Sweden, and from De Bilt, Netherlands, carried out in 1965 and 1966. The energy spectrum of primary electrons obtained at solar minimum time clearly shows a bend around 2–3 GeV. Between 3 and 30 GeV this spectrum is expressed by[Formula: see text]
Distribution and lifetime of cosmic-ray electrons in the galaxy
Authors: Tanaka Y.
Published: April 2011

When the source spectrum of cosmic-ray electrons has the form E−γ, the equilibrium spectrum is expected to approach E−γ−1 above a critical energy Ec, where Ec is a function of the storage time and the energy loss rate due to synchrotron radiation and the inverse Compton effect. The observed electron spectrum, which is a combination of the latest results of the Minnesota group, Chicago group, Bombay group, and Leiden group, can be well expressed by a single power law (~E−2.5) for 3 < E < 100 GeV. A knee observed at about 3 GeV might also be due to a solar effect.Thus the possibilities are either [Formula: see text] or Ec > 50 GeV. These two cases lead to largely different models with respect to the source spectrum, the acceleration, the storage time, and the distribution of cosmic-ray electrons in the galaxy. The radio observations are compatible with the hypothesis based on [Formula: see text].
The composition of low-energy cosmic rays in 1965
Authors: Hagge D. E. , Balasubrahmanyan V. K. , McDonald F. B.
Published: April 2011

Primary cosmic-ray energy spectra and charge composition have been measured during the 1965 period of solar modulation minimum. A dE/dx vs. E type of scintillator–photomultiplier detector on board the eccentric-orbiting NASA spacecraft OGO-I was used. The charge composition was measured through neon over an energy range of 25 to 200 MeV/nucleon, depending upon the specific component. The spectra for all groups are nearly flat during this time, with the oxygen flux at about 0.005 nucleus/(M2-sr-s-MeV/nucleon). The relative abundances found are Li, 0.27; Be, 0.11; B, 0.37; C, 1.20; N, 0.30; O 1.00; F, [Formula: see text]; Ne, 0 12 An L/M ratio of 0.30 ± 0.06 is found.
The low-energy cosmic-ray nuclei and their propagation in interstellar space
Authors: Comstock G. M.
Published: April 2011

The differential energy spectra of the cosmic-ray nuclei helium, carbon, nitrogen, and oxygen above 30 MeV/nucleon, boron, neon, magnesium, and silicon above 50 MeV/nucleon, and the iron group above 100 MeV/nucleon, measured in October–December 1964 and May–June 1965 by the University of Chicago charged-particle telescope on board the OGO-I satellite (Comstock et al. 1966b), have been corrected to take account of the effective depletion depth of the gold–silicon solid-state detectors used for rate-of-energy-loss measurement. Additional data from October to December 1965 are included. The magnitudes and relative shapes of the spectra deduced by extrapolation to nearby interstellar space place important constraints on the allowed modes of interstellar propagation for these nuclei. Two-component models are shown to account for most of the observed properties of the interstellar cosmic-ray nuclei.
The energy spectrum of the component of the cosmic radiation
Authors: Freier P. S. , Waddington C. J.
Published: April 2011

Three large stacks of nuclear emulsions were exposed during 1964–66 on high-altitude balloons launched from Fort Churchill, Canada; Texas, U.S.A.; and Hyderabad, India. These stacks have been used to study the energy spectrum of the cosmic-ray nuclei of calcium and heavier (the so-called VH nuclei). These measurements result in integral intensity values for energies greater than 7.1, 1.58, and 1.00 GeV per nucleon, together with differential intensities over the range [Formula: see text] MeV per nucleon. Differential intensities were also found for lighter nuclei over varying energy ranges. The differential spectrum observed has a maximum value of about 1.6 × 10−3 nuclei/m2 sr s MeV per nucleon around [Formula: see text] MeV per nucleon and falls off at both higher and lower energies. These values are based on the observation of a total of some 1 600 VH nuclei. The energy spectrum has been compared with that observed at similar times for the helium nuclei in order to study the influences of ionization energy losses during propagation of these high-Z nuclei. These observations are interpreted as implying that if the source spectra of the VH nuclei and the helium nuclei are similar, then the VH nuclei have traversed less than 1 g/cm2 of matter while ionization energy loss has been the dominant acceleration term.
Studies on cyclic variations of muons collected underground close to the zenith
Authors: Mabboux C. , Mosrin P. , Scherer M. , Mabboux-Tariel G.
Published: April 2011

The time distribution of the occurrence of muons detected under 440 m of rock in an iron-ore mine, during the course of the whole year 1963, has been analyzed using a newly designed method. Results obtained indicate the presence of a strong sidereal wave with a maximum in the galactic plane, associated with other components which can be related to solar influences.
Sidereal time variation of high-energy cosmic rays observed by an air Cerenkov telescope
Authors: Sekido Y. , Nagashima K. , Kondo I. , Murayama T. , Okuda H. , Sakakibara S. , Fujimoto K.
Published: April 2011

Using the cosmic-ray telescope No. 3 (air Cerenkov telescope) at Nagoya, observations of high-energy (~200 GeV) cosmic rays were continued during the period from February 1964 to March 1966. The observations were made at a fixed zenith angle Z = 60° and at two azimuths A = 72° and 288°. With this setting, the celestial sphere was scanned in the declination band between 25° and 40 °N. Using the difference between the two diurnal vectors observed at 72° (east) and 288° (west), the anisotropy, free from any diurnal variation of meteorological origin, was obtained corresponding to each of four seasons. From these four anisotropy vectors, the solar anisotropy was found to be insignificant, but the sidereal anisotropy was as follows:[Formula: see text]
On cosmic-ray interactions with photons
Authors: Kuzmin V. A. , Zatsepin G. T.
Published: April 2011

Various effects of high-energy cosmic-ray interactions with cosmic blackbody radiation are considered, particularly the cutoff of the cosmic-ray energy spectrum at [Formula: see text] for protons, and at [Formula: see text] for α particles and other nuclei, as a consequence of photo-production of pions and photodisintegration of nuclei.If quasars and similar objects are indeed the source of high-energy cosmic rays, the protons and nuclei of energy E > (3–10) × 1015 eV would encounter considerable difficulty in being injected from these sources because of interactions with photons, with the result that: (1) the cosmic-ray flux with energy above [Formula: see text] to 3 × 1016 eV may have predominantly proton composition, (2) the cosmic-ray flux may have steeply decreasing intensity in the energy ranpe E = (3–30) × 1015 eV.
Cosmic-ray deuterium and helium-3 nuclei
Authors: Ramaty R. , Lingenfelter R. E.
Published: April 2011

Assuming that cosmic-ray deuterons and helium-3 nuclei are of secondary origin, we show that a unique determination of both the cosmic-ray path-length and the residual interplanetary field modulation at solar minimum may be made from a comparison of the calculated and measured intensities of these two nuclei. This determination does not depend on any assumptions regarding either the source spectra or the unmodulated proton to alpha particle ratio of the primary cosmic rays. The production of deuterium and helium-3 by cosmic-ray interactions in the galaxy is calculated considering energy-dependent cross sections, interaction kinematics, and demodulated cosmic-ray spectra. The resulting flux at the earth is obtained by taking into account leakage from the galaxy, ionization losses, nuclear breakup, and modulation. From a comparison of these calculations with the measured deuterium and helium-3 intensities at the earth, we conclude that within the experimental uncertainties all the data can be understood in terms of an energy-independent cosmic-ray path-length of 4 ± 1 g/cm2 and a residual interplanetary field modulation at solar minimum of the form exp(–η/Pβ) with η = 0.4 ± 0.1 BV, where P and β are the rigidity and velocity.
Preferential acceleration of heavy ions from thermal velocities
Authors: Melrose D. B.
Published: April 2011

The acceleration of ions from thermal velocities is analyzed to determine conditions under which heavy ions can be preferentially accelerated. Two accelerating mechanisms involving high-and low-frequency hydromagnetic waves respectively are considered. Preferential acceleration of heavy ions occurs for high-frequency waves if the frequency spectrum falls off faster than (frequency)−1. For the low-frequency waves heavy ions are less effectively accelerated than lighter ions. However, very heavy ions can be preferentially accelerated, the abundances of the very heavy ions being enhanced by a factor Ai over the thermal abundances. Acceleration of ions in the envelope of the Crab nebula is considered as an example.
The galactic magnetic field derived from cosmic-ray electrons
Authors: Okuda H. , Tanaka Y.
Published: April 2011

An estimate of the galactic magnetic field is obtained by combining new results in the cosmic-ray electron spectrum and the recent radio data. The lower and upper limits of the magnetic field in the galactic disk are derived from two alternative models of field configuration; i.e. (0.5–1.0) × 10−5 gauss near the solar system and (1.0–2.0) × 10−5 gauss near the galactic center, respectively. The magnetic field in the halo is estimated to be larger than 2.5 × 10−6 gauss.
High-energy pion interactions
Authors: McCusker C. B. A. , Peak L. S. , Woolcott R. L. S.
Published: April 2011

In this paper the results of a line scan of 640 cm of narrow-angle secondary tracks (EPt > 100 GeV) from proton primary jets in emulsions are presented. The proton component was eliminated by disregarding the smallest-angle track unless there was clear evidence that it did not represent a proton. The energy of each pion interaction found was estimated by the following procedure. The various energy estimators were modified to take account of multiple-collision events and then the energy and inelasticity which gave the closest agreement between the energy estimators E(charged), E(median), E(Castagnoli), E(quartile), and Ept were used.The π-meson mean free path was found to be 40 cm (~26 mb) at an average energy of 450 GeV. The average multiplicity of the sample (of pion interactions) was found and shown to be consistent with a log E dependence. The average value of Nh was found and contrasted with previous results at lower energies. The results also show that on the average one pion carries away ~40% of the incident energy.In tracing the above path-length seven examples of direct pair production were identified giving a mean free path of 90 cm.
Mean characteristics of the process of multiple production at 1011–1012 eV
Authors: Dobrotin N. A. , Fetisov I. N. , Guseva V. V. , Kotelnikov K. A. , Lebedev A. M. , Maximenko V. M. , Puchkov V. S. , Slavatinsky S. A. , Zelevinskaya N. G.
Published: April 2011

The dependence of the mean characteristics of multiple production at 1011–1012 eV (i.e., [Formula: see text] = multiplicity of charged secondaries, [Formula: see text] = energy of secondaries in the c.m.s., σc = parameter of anisotropy) on the primary energy E0 is studied experimentally. The analysis is based on 73 interactions of cosmic-ray particles with LiH and C targets observed in two sets of experiments (Pamir and Tien-Shan). The main conclusions are as follows: (1) the dependence of [Formula: see text] on E0 is compatible with both a power function ns ~ E01/4[Formula: see text] and a logarithmic function ns ~ log E0 (theory of peripheral interactions); [Formula: see text] the increase of [Formula: see text] and σc with E0 is compatible with predictions of the fireball model; (3) in coordinates log tan θlab 10% of the interactions have a bimodal angular distribution.
The study of interactions of particles with energy above 1012 eV by the method using an ionization calorimeter and nuclear emulsions with time selection
Authors: Brikker S. I. , Grigorov N. L. , Podgurskaya A. V. , Poperyekova L. M. , Savelyeva A. I. , Sobinyakov V. A. , Shestoperov V. Ya. , Babayan Kh. P. , Marutyan N. A. , Mitoyan S. A.
Published: April 2011

A device has been described that makes it possible to record the time of high-energy-particle interaction events in a carbon target. Nuclear emulsions are used over the 10—m2 calorimeter area. The results using this arrangement are presented and compared with those obtained earlier.
Energy spectra of nuclear-active particles at mountain altitudes
Authors: Grigorov N. L. , Sobinyakov V. A. , Tretyakova Ch. A. , Shestoperov V. Ya. , Babayan Kh. P. , Boyadjan N. G. , Mamidjanyan E. A.
Published: April 2011

The results of measurements of the energy spectrum of nuclear-active particles carried out by means of an ionization calorimeter and an installation recording ionization bursts at the altitude of 3 200 m above sea level are presented.
Inelastic interaction cross sections for nuclear-active particles of energy 5 × 1010 to 1012 eV on carbon and iron nuclei
Authors: Andronikashvili E. L. , Chikovani G. E. , Garibashvili D. I. , Gabunia L. L. , Kakauridze D. B. , Kotlyarevski D. M. , Manjavidze Z. Sh. , Roinishvili N. N. , Razdolskaya L. A. , Sherer E. N.
Published: April 2011

Inelastic interactions of nuclear-active particles in carbon and iron have been studied using cloud chambers in a magnetic field and an ionization calorimeter at Tskhra-Tskharo Pass at an altitude of 2 500 m above sea level. The installation consists of two cloud chambers 2 × 1 × 0.4 m3 in a magnetic field of 7 000 oersteds and an ionization calorimeter of total thickness about 800 g/cm2. It is triggered when an energy greater than 5 × 1010 eV is released in the ionization calorimeter. The measurements in carbon and iron can be taken simultaneously. Results taken up to the present show that the mean free path for carbon is (96 ± 13) g/cm2 and for iron (130 ± 6) g/cm2.
Determination of the mean multiplicity of particles produced in a nuclear interaction using the method of the inverse problem
Authors: Astafiev V. A.
Published: April 2011

The possibility of the determination of the mean multiplicity of secondaries, n(E), with the aid of the cascade characteristics has been studied using the nuclear cascade with one-type particles as an example. For the simple model of interaction with the inelasticity coefficient k = 1 the energy spectra of particles in the showers produced by the particles of various energies have been calculated. The function n(E) has been restored in the higher-energy range on the assumption that the calculated spectra are known from the "experiment," and the function n(E) at low energies has been measured within good accuracy. Estimates of the accuracy of the cascade data necessary for determining n(E) within the given accuracy are presented.
An interpretation of cosmic-ray jets
Authors: Imaeda K.
Published: April 2011

A frequency function of multiplicity and dispersion of the log tan θ plot of the secondary particles of cosmic-ray jets is derived and compared with the experimental results. On the basis of this distribution law together with the "isobar-fireball" model, the characteristic features of cosmic-ray jets are discussed. The predictions and validity of this model for jets of energy 1013 to 1016 eV are examined in the light of experiments, and a possible change in the characteristic feature of jets around 1016 eV energy is suggested.
Search for heavy singly charged particles in cosmic rays
Authors: Kasha Henry , Hawkins C. J. B. , Stefanski R. J.
Published: April 2011

A search is being conducted for heavy singly charged particles which might be found in cosmic rays deep in the atmosphere. The search is particularly motivated by the possible existence of particles which might form fundamental triplet representations of SU3. It has been possible to show that such particles will likely have velocities smaller than c near sea level if their angle of incidence is near 15° from the horizontal. The particles are identified by their momentum, charge, and time of flight through the apparatus. No such particles have been found, and the preliminary data give a limit of 2.8 × 10−8 cm−2 sr−1 s−1 at 90% significance level for particles with masses greater than 5 GeV/c2 with a velocity between 0.5c and 0.75c. On the basis of a particular model of production and diffusion through the atmosphere this flux corresponds to a production cross section by nucleon–nucleon interactions of about 10−29 cm2.
Search for particles with charge 2/3e in cosmic rays
Authors: Kasha H. , Larsen R. C. , Leipuner L. B. , Adair R. K.
Published: April 2011

The flux of particles with charge equal to [Formula: see text] of the electron charge which reach sea level from the vertical with relativistic velocities was found to be less than 2.7 × 10−10 cm−2 sr−1 s−1 at 90% confidence level. The particles were identified through their characteristic energy loss in a 48-counter hodoscope. The result seems inconsistent with a model of hadrons as being a composite of quarks.