scholarly journals Absorption of penetrating cosmic ray particles in gold

1939 ◽  
Vol 172 (951) ◽  
pp. 517-529 ◽  
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Close Agreement ◽  
Cosmic Ray ◽  
Soft Component ◽  
Additional Energy ◽  
Hard Component ◽  
Metal Plates ◽  
Theoretical Predictions ◽  
Absorption Measurements

A considerable amount of experimental data on the energy loss of cosmic-ray particles in metal plates is now available. Much of this, however, represents work carried out before the separate nature of the hard and soft components was fully understood, so that in many cases unsuitable conditions make the interpretation of the results difficult. The soft component is known to consist of electrons, and these predominate in the cosmic-ray energy spectrum for energies less than 2 x 10 8 e-volts. It has been verified for these electrons that the energy loss by ionization (Corson and Brode 1938) and by radiative collisions (Blackett 1938) is in close agreement with the theoretical predictions. At energies greater than 2 x 10 8 e-volts, very few electrons are found at sea level, and for all higher energies the majority of the particles are now considered to be mesotrons. These, together with an uncertain, but small, number of protons form the hard component of the cosmic rays. Absorption measurements for the hard component are more difficult than for the electrons, since the particles are, in general, of higher energy and the loss of energy in an absorbing plate is very much smaller. The early observations (Blackett and Wilson 1937; Crussard and Leprince Ringuet 1937; Wilson 1938 a ) lead to the conclusion that at an electron energy ( E e = 300 Hρ )* of about 5 x 10 8 e-volts, the total energy loss of penetrating particles was very small—of the same order as that due to ionization alone —but that at higher energies, E e ~ 1.5 x 10 9 e-volts, a considerable additional energy loss took place, which did not appear to be attributable to the inclusion of electrons in the measurements (Wilson 1938 a ). With the comparatively thin absorbing plates used, however, it was not certain that all electrons had been excluded from these measurements.

scholarly journals On the photon component of cosmic radiation and its absorption coefficient

1940 ◽  
Vol 175 (960) ◽  
pp. 88-100 ◽  
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Cosmic Radiation ◽  
Cosmic Ray ◽  
High Energy ◽  
Soft Component ◽  
Simple Method ◽  
Metal Plates ◽  
Experimental Values ◽  
Photon Component

It has been established that the soft component of the cosmic radiation consists of electrons and photons. Much experimental data on the electrons forming the soft component are available and they are known to form a fraction of about 25-30% of the whole beam of ionizing particles at sea level, excluding particles below 10 7 eV (e.g. Rossi 1933; Nielsen and Morgan 1938). The energy spectrum of the electrons is known roughly from the work of Blackett (1938), Wilson (1939) and others. The energy loss of electrons in metal plates has been investigated by Anderson and Neddermeyer (1934), Blackett and Wilson (1937), Williams (1939), Wilson (1938, 1939), showing that the experimental values of the energy loss are in agreement with the prediction of the quantum theory (Bethe and Heitler 1934). Much less is known about the photon component of cosmic radiation, as comparatively few experiments have been carried out to investigate their properties. Further the results of the investigations available are partly contradictory. The theory of the absorption of high energy photons has been worked out to the same extent as for electrons (Bethe and Heitler). Owing to the lack of experimental material, the theory could be tested only up to energies of about five million volts (McMillan 1934; Gentner 1935). The success of the theory of cascade showers due to Bhabha and Heitler (1937) and Carlson and Oppenheimer (1937), based on the Bethe-Heitler theory of electrons and photons, provides however an indirect test for the validity of the absorption formula for high energy photons. The lack of experimental data on high energy photons is due to the difficulties in the method of observation; photons unlike electrons cannot be observed directly. In the present paper a simple method for investigating cosmic-ray photons is described. Using this method, data about the number, energy distribution and absorption of cosmic-ray photons have been obtained.

scholarly journals The scattering of cosmic ray particles in metal plates

1938 ◽  
Vol 165 (921) ◽  
pp. 209-215 ◽  
Author(s):  
Patrick Maynard Stuart Blackett ◽  
J. G. Wilson
Keyword(s):  
Energy Loss ◽  
Multiple Scattering ◽  
Cosmic Ray ◽  
Numerical Results ◽  
Cloud Chamber ◽  
The Other ◽  
Metal Plates ◽  
Theoretical Predictions ◽  
The Mean ◽  
Average Angle

Using an ordinary cloud chamber, Anderson (1933) measured the average angle of scattering of cosmic-ray particles of energy up to 3 x 10 8 e-volts in a lead plate of thickness 1·1 cm. Williams (1936) pointed out that, in such experiments, the scattering is multiple, and that the observed values agreed with the theoretical predictions, assuming the particles to be electrons. Recently Neddermeyer and Anderson (1937) have made some new measure­ments using a counter-controlled cloud chamber and a 1 cm. platinum plate. No numerical results are given, but the observed scattering of particles of energy up to 5 x 10 8 e-volts, which appears to be the limit of the energy measurements, seems in rough agreement with the earlier results. Using the counter-controlled cloud chamber already described by Blackett (1936) and by Blackett and Brode (1936), the multiple scattering of cosmic-ray particles of energy up 9 x 10 9 e-volts in lead and copper plates has been measured. In order to make such measurements possible, it is necessary to reduce as far as possible the distortion of the tracks in the chamber. The technique by which this can be achieved has been described by Blackett and Wilson (1937) in connexion with the measure­ment of the energy loss of rays in traversing metal plates. In fact, the photographs taken for the measurement of the energy loss were, amongst others, found suitable for the measurement of the scattering. The angle of scattering was measured by means of a goniometer eyepiece attached to a travelling microscope. The cross-wires were set tangentially to the track, first on one side and then on the other side of the plate. The mean of the two measured angles of deflexion, obtained from the two stereoscopic photographs, was taken as giving the projection on the plane of the chamber of the actual angle of scattering.

Energy Loss for Swift Heavy Ions in Different Elemental Absorbers: A Different Approach for Effective Charge Parameterization

2015 ◽  
Vol 238 ◽  
pp. 196-205
Author(s):  
B. Rani ◽  
Kalpana Sharma ◽  
Neetu ◽  
Anupam ◽  
Shyam Kumar ◽  
...  
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Effective Charge ◽  
Heavy Ions ◽  
Close Agreement ◽  
Input Parameter ◽  
Quantum Mechanical ◽  
Swift Heavy Ions ◽  
Calculated Energy ◽  
Semi Empirical

The energy loss for swift heavy ions, covering Z=3-29(~0.2 - 5.0MeV/n), has been calculated in the elemental absorbers like C, Al and Ti. The present calculations are based on Bohr’s approach applicable in both classical and quantum mechanical regimes. The major input parameter, the effective charge, has been calculated in a different way without any empirical/semi-empirical parameterization. The calculated energy loss values have been compared with the available experimental data which results in a close agreement.

scholarly journals The energy loss of cosmic ray particles in metal plates

1937 ◽  
Vol 160 (901) ◽  
pp. 304-323 ◽  
Keyword(s):  
Magnetic Field ◽  
Energy Loss ◽  
Cosmic Ray ◽  
Metal Plate ◽  
Usual Method ◽  
Cloud Chamber ◽  
Zero Magnetic Field ◽  
Metal Plates ◽  
Curvature Measurements ◽  
The Difference

Measurements have been made of the energy loss of cosmic ray particles in metal plates, making use of a counter controlled cloud chamber in a magnetic field (Blackett 1936). A metal plate was placed across the centre of the chamber and the energy loss of a ray was deduced from the difference of the curvature of a track above and below the plate. Energy loss measurements by this method have been carried out by Anderson and Neddermeyer (1936) up to an energy of about 4 x 10 8 e-volts and recently by Crussard and Leprince-Ringuet (1937) up to an energy of 1·2 x 10 9 e-volts. The curvature measurements were made mainly by means of the optical null method recently described (Blackett 1937 a ) and this proved invaluable. It would have been hard to obtain so high an accuracy by the usual method of measuring coordinates. The curvature corrections to be applied to the measured curvatures were obtained by measurements on tracks in zero magnetic field (Blackett and Brode 1936). Two separate distortion curves were required, one for the top and one for the bottom of the chamber.

Trajectories of Single and Double Jets Injected Into a Crossflow of Arbitrary Velocity Distribution

1979 ◽  
Vol 101 (2) ◽  
pp. 217-223 ◽  
Author(s):  
Toshiaki Makihata ◽  
Yoshihiro Miyai
Keyword(s):  
Experimental Data ◽  
Integral Equation ◽  
Velocity Distribution ◽  
Close Agreement ◽  
Theoretical Calculations ◽  
Distribution Ranges ◽  
Theoretical Predictions ◽  
Conservation Of Momentum ◽  
Momentum Integral ◽  
Arbitrary Velocity

This paper describes the results of our experiments on and theoretical predictions of the trajectories of multiple buoyant and nonbuoyant jets. Our theoretical calculations employed a finite difference method of analysis of both a momentum integral equation and the law of conservation of momentum. Results are presented for cases in which the ratio of the jet velocity to the crossflow of arbitrary velocity distribution ranges from 1.2 to 10.6. Our theoretical predictions are shown to be in close agreement with available experimental data.

scholarly journals The nature of the penetrating component of cosmic rays

1938 ◽  
Vol 165 (920) ◽  
pp. 11-31 ◽  
Author(s):  
Patrick Maynard Stuart Blackett
Keyword(s):  
Energy Loss ◽  
Average Energy ◽  
Great Majority ◽  
Cosmic Ray ◽  
High Energy ◽  
Transition Curve ◽  
Metal Plates ◽  
The Difference ◽  
Normal Electron ◽  
Transition Curves

The measurements by Neddermeyer and Anderson (1937) of the absorp­tion of cosmic-ray particles of low energy by metal plates differ in certain respects from those by Blackett and Wilson (1937). The former results showed that, in the energy range 1∙2 x 10 8 to 5 x 10 8 e-volts, two types of particles exist, an absorbable group assumed to behave as theory predicts of electrons and a much more penetrating group, attributed provisionally to heavier particles. On the other hand, we found that all the rays with energy under 2 x 10 8 e-volts were absorbed like electrons, while for rays of greater energy the average energy loss was very much less. Though a very few energetic particles were found to have a high energy loss, insufficient evidence was then available to justify classifying them as of a nature distinct from the less absorbable rays. Thus we obtained definite experimental evidence that the energy loss of the great majority of the rays varies rapidly with their energy. We concluded, therefore, that the energy loss of a normal electron varies with its energy. We now believe this to be probably false, since the success of the cascade theory of showers, in explaining the transition curve in the atmosphere, and a large part, at any rate, of the phenomena of the transition curves of showers and bursts, has provided fairly strong evidence that there must be a very few energetic rays at sea-level, which have the full radiation loss of electrons, even in heavy elements. It follows that the great majority of the rays, for which the energy loss certainly varies rapidly with energy, are probably not normal electrons. We therefore agree with the view of Neddermeyer and Anderson that it is likely that there are two types of particles present, though the difference in behaviour only exists for energies over 2 x 10 8 e-volts.

IONIZATION LOSS BY COSMIC-RAY MU-MESONS IN ARGON

1959 ◽  
Vol 37 (2) ◽  
pp. 189-202 ◽  
Author(s):  
Georges Hall
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Ionization Chamber ◽  
Cosmic Ray ◽  
Statistical Distribution ◽  
Experimental Curve ◽  
Energy Losses ◽  
Ionization Loss ◽  
Electron Collection ◽  
Probable Loss

The ionization of argon by cosmic-ray mu-mesons of minimum specific ionization has been studied by means of a calibrated pressure-ionization chamber using electron collection. Corrections which are shown to be necessary have been applied to the experimental data. The shape of the experimental curve of statistical distribution of energy loss agrees with the theoretically predicted shape, for energy losses greater than the most probable loss (300 kev).

scholarly journals Meson formation and the geomagnetic effects

1947 ◽  
Vol 192 (1028) ◽  
pp. 99-114 ◽  
Keyword(s):  
Experimental Data ◽  
Quantitative Analysis ◽  
Cosmic Rays ◽  
Charged Particles ◽  
Meson Production ◽  
Cosmic Ray ◽  
Average Multiplicity ◽  
Soft Component ◽  
Positively Charged ◽  
Mode Of Production

The experimental data on the cosmic-ray geomagnetic effects are used to provide information on the nature of the primary cosmic rays and on the mode of production of the meson component. The relevant arguments are first reviewed in a qualitative way and then elaborated by a quantitative analysis, which is not dependent upon any specific theory of meson production. Three main possibilities are discussed, the so-called proton, ‘mixed’ and soft component hypotheses (see §1 for definitions). It is concluded that the bulk of the mesons must arise from protons (or possibly other heavier positively charged particles). The analysis suggests that the average multiplicity of the process of meson production is about nine. From consideration of the asymmetry at high altitudes it seems likely that the primary radiation consists of protons and electrons (equally positive and negative) in the ratio of about one proton to four electrons.

scholarly journals Derivation of Muon Intensities in Sea-water Depths up to 1400 M.W.E. from a Recent Primary Cosmic Ray Spectrum

1984 ◽  
Vol 37 (5) ◽  
pp. 575 ◽  
Author(s):  
DP Bhattacharyya ◽  
Pratibha Pal ◽  
A Mukhopadhyay
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Pair Production ◽  
Sea Water ◽  
Cosmic Ray ◽  
Muon Energy ◽  
Energy Relation ◽  
Scaling Hypothesis ◽  
Nuclear Interactions ◽  
Water Depths

The muon intensities in sea-water depths up to 1400 M.W.E. have been derived from a recent primary cosmic ray spectrum. The scaling hypothesis of Feynman has been used in the calculation of meson spectra in the atmosphere. The range-energy relation for muons in sea water, used in the present work, accounts for the muon energy loss in sea water due to collisions, pair production, bremsstrahlung and nuclear interactions. The calculated muon range spectrum in sea water is well in accord with the experimental data obtained by Higashi et al. (1966), Davitaev et al. (1969), and Rogers and Tristam (1981, 1983

scholarly journals The energy loss of penetrating cosmic-ray particles in copper

1938 ◽  
Vol 166 (927) ◽  
pp. 482-501 ◽  
Keyword(s):  
Energy Loss ◽  
Cosmic Ray ◽  
Low Energy ◽  
Complete Agreement ◽  
Absorption Properties ◽  
Extended Range ◽  
The Mean ◽  
Absorption Measurements ◽  
Made In ◽  
Number Of Particles

Absorption measurements for cosmic-ray particles by the cloud chamber method have been made in heavy metals by Anderson and Neddermeyer (1936), Crussard and Leprince Ringuet (1937), Blackett and Wilson (1937) and by Neddermeyer and Anderson (1937). Anderson and Neddermeyer have confined their attention to particles of low energy and give (1937) reasons for supposing that particles of differing absorption properties exist in this region ( E < 4 × 10 8 e-volts). This result is only partially confirmed by more recent work (Blackett 1938) which shows that for E < 2 × 10 8 e-volts the mean energy loss of all particles and the distribution of losses among the particles are in accord with the predicted behaviour of electrons, and that there is no appreciable number of particles at this energy with non-electronic absorption properties. It is only for energies above 2 × 10 8 e-volts that two different kinds of particle are found. In this region the very few absorbable particles are probably normal electrons, while the penetrating particles differ in some way from normal electrons but apparently become indistinguishable from them when the energy falls below about 2 × 10 8 e-volts. Measurements of the absorption of the particles in the region where penetrating particles predominate have been made by Blackett and Wilson over an extended range, while Crussard and Leprince Ringuet have measured the energy loss of particles of a mean energy about 8 × 10 8 e-volts and report a mean loss which is in accord with the measurements of Blackett and Wilson. Upon the nature of these penetrating particles there is not at present complete agreement. It is now generally believed that the particles are more massive than electrons and that they radiate according to the classical (Bethe-Heitler) formula appropriate to their mass.

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