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.

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.

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 Energy loss measurements of inclined muon bundles in the Cherenkov water detector

2019 ◽  
Vol 208 ◽  
pp. 08006
Author(s):  
R.P. Kokoulin ◽  
N.S. Barbashina ◽  
A.G. Bogdanov ◽  
S.S. Khokhlov ◽  
V.A. Khomyakov ◽  
...  
Keyword(s):  
Energy Loss ◽  
Average Energy ◽  
Cosmic Ray ◽  
Muon Energy ◽  
Single Experiment ◽  
Muon Component ◽  
Energy Deposit ◽  
Tracking Detector ◽  
Wide Range ◽  
Muon Bundles

An experiment on the measurements of the energy deposit of inclined cosmic ray muon bundles is being conducted at the experimental complex NEVOD (MEPhI). The complex includes the Cherenkov water calorimeter with a volume of 2000 m3 and the coordinate-tracking detector DECOR with a total area of 70 m2. The DECOR data are used to determine the local muon densities in the bundle events and their arrival directions, while the energy deposits (and hence the average muon energy loss) are evaluated from the Cherenkov calorimeter response. Average energy loss carries information about the mean muon energy in the bundles. The detection of the bundles in a wide range of muon multiplicities and zenith angles gives the opportunity to explore the energy range of primary cosmic ray particles from about 10 to 1000 PeV in the frame of a single experiment with a relatively small compact setup. Experimental results on the dependence of the muon bundle energy deposit on the zenith angle and the local muon density are presented and compared with expectations based on simulations of the EAS muon component with the CORSIKA code.

The rate of energy loss of high-energy cosmic ray muons

1963 ◽  
Vol 275 (1362) ◽  
pp. 391-410 ◽  
Keyword(s):  
Energy Spectrum ◽  
Energy Loss ◽  
Sea Level ◽  
Cosmic Ray ◽  
Nuclear Interaction ◽  
High Energy ◽  
Level Energy ◽  
Muon Spectrum ◽  
The Third ◽  
Muon Mass

The rate of energy loss of muons is examined by com paring the observed depth-intensity relation with that predicted from a knowledge of the sea-level energy spectrum of cosmic ray muons. The evidence for each of the parameters entering into the analysis is assessed and estimates are made of the sea-level muon spectrum up to 10000 GeV and the depth-intensity relation down to 7000 m.w.e. The effect of range-straggling on the underground intensities is considered and shown to be important at depths below 1000 m.w.e. Following previous workers the energy loss relation is written as -d E /d x =1.88+0.077 in E ' m / mc 2 + b E MeV g -1 cm 2 , where E ' m is the maximum transferrable energy in a /i-e collision and m is the muon mass. The first two terms give the contribution from ionization (and excitation) loss and the third term is the combined contribution from pair production, bremsstrahlung and nuclear interaction. The best estimate of the coefficient b from the present work is b = (3.95 + 0.25) x 10 -6 g -1 cm 2 over the energy range 500 to 10000 GeV, which is close to the theoretical value of 4.0 x 10 -6 g -1 cm 2 . It is concluded that there is no evidence for any marked anomaly in the energy loss processes for muons of energies up to 10000 GeV.

scholarly journals Starburst Energy Feedback Seen through HCO+/HOC+ Emission in NGC 253 from ALCHEMI

2021 ◽  
Vol 923 (1) ◽  
pp. 24
Author(s):  
Nanase Harada ◽  
Sergio Martín ◽  
Jeffrey G. Mangum ◽  
Kazushi Sakamoto ◽  
Sebastien Muller ◽  
...  
Keyword(s):  
Galactic Center ◽  
Cosmic Ray ◽  
Ionization Rate ◽  
High Energy ◽  
Photon Flux ◽  
Starburst Galaxy ◽  
Energy Feedback ◽  
The Difference ◽  
Uv Photons ◽  
Molecular Abundances

Abstract Molecular abundances are sensitive to the UV photon flux and cosmic-ray ionization rate. In starburst environments, the effects of high-energy photons and particles are expected to be stronger. We examine these astrochemical signatures through multiple transitions of HCO+ and its metastable isomer HOC+ in the center of the starburst galaxy NGC 253 using data from the Atacama Large Millimeter/submillimeter Array large program ALMA Comprehensive High-resolution Extragalactic Molecular inventory. The distribution of the HOC+(1−0) integrated intensity shows its association with “superbubbles,” cavities created either by supernovae or expanding H ii regions. The observed HCO+/HOC+ abundance ratios are ∼10–150, and the fractional abundance of HOC+ relative to H2 is ∼1.5 × 10−11–6 × 10−10, which implies that the HOC+ abundance in the center of NGC 253 is significantly higher than in quiescent spiral arm dark clouds in the Galaxy and the Galactic center clouds. Comparison with chemical models implies either an interstellar radiation field of G 0 ≳ 103 if the maximum visual extinction is ≳5, or a cosmic-ray ionization rate of ζ ≳ 10−14 s−1 (3–4 orders of magnitude higher than that within clouds in the Galactic spiral arms) to reproduce the observed results. From the difference in formation routes of HOC+, we propose that a low-excitation line of HOC+ traces cosmic-ray dominated regions, while high-excitation lines trace photodissociation regions. Our results suggest that the interstellar medium in the center of NGC 253 is significantly affected by energy input from UV photons and cosmic rays, sources of energy feedback.

A LARGE-AREA LIQUID SCINTILLATION COUNTER AND SOME MEASUREMENTS ON HIGH-ENERGY COSMIC-RAY PARTICLES

1958 ◽  
Vol 36 (1) ◽  
pp. 54-72 ◽  
Author(s):  
C. H. Millar ◽  
E. P. Hincks ◽  
G. C. Hanna
Keyword(s):  
Energy Loss ◽  
Liquid Scintillation ◽  
Scintillation Counter ◽  
Pulse Height ◽  
Central Area ◽  
Cosmic Ray ◽  
High Energy ◽  
Liquid Scintillation Counter ◽  
Height Distribution ◽  
Half Maximum

A liquid scintillation counter is described which consists of a [Formula: see text] in. by [Formula: see text] in. by 2 in. Plexiglas tank of terphenyl plus α-naphthylphenyloxazole (αNPO) in triethylbenzene. The tank is surrounded by MgO powder and viewed by a total of eight RCA Type 5819 photomultiplier tubes along two opposite edges. For normally incident fast μ-mesons a peaked pulse height distribution is observed, 20.5% in width at half-maximum for the central area of the counter, broadening to 25–30% at the perimeter, and estimated to be 25% over-all. When the Landau distribution in energy loss (width 18% at half-maximum) and the geometric spread are taken into account, a counter resolution function 8% in width at half-maximum is obtained for the central area of the counter, or 18% for the counter as a whole.The most probable pulse height for 0.30 Bev. μ-mesons is 1.6 ± 0.5% higher than for 2.2 Bev. μ-mesons, in close agreement with the Bethe–Bloch theory as extended by Symon and with a density correction calculated by the method of Sternheimer. Pulse heights from protons in the region 0.3 to 0.8 Bev. vary directly with the theoretically computed energy loss in the counter. Peak position and resolution are unchanged by a flux of 12 mr./hr. of thorium γ-rays.

scholarly journals Leading jets and energy loss

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Duff Neill ◽  
Felix Ringer ◽  
Nobuo Sato
Keyword(s):  
Energy Loss ◽  
Cross Sections ◽  
Evolution Equations ◽  
Average Energy ◽  
Longitudinal Momentum ◽  
Longitudinal Momentum Fraction ◽  
Inclusive Jets ◽  
Jet Energy ◽  
The Difference ◽  
Additional Reference

Abstract The formation and evolution of leading jets can be described by jet functions which satisfy non-linear DGLAP-type evolution equations. Different than for inclusive jets, the leading jet functions constitute normalized probability densities for the leading jet to carry a longitudinal momentum fraction relative to the initial fragmenting parton. We present a parton shower algorithm which allows for the calculation of leading-jet cross sections where logarithms of the jet radius and threshold logarithms are resummed to next-to-leading logarithmic (NLL′) accuracy. By calculating the mean of the leading jet distribution, we are able to quantify the average out-of-jet radiation, the so-called jet energy loss. When an additional reference scale is measured, we are able to determine the energy loss of leading jets at the cross section level which is identical to parton energy loss at leading-logarithmic accuracy. We identify several suitable cross sections for an extraction of the jet energy loss and we present numerical results for leading subjets at the LHC. In addition, we consider hemisphere and event-wide leading jets in electron-positron annihilation similar to measurements performed at LEP. Besides the average energy loss, we also consider its variance and other statistical quantities such as the KL divergence which quantifies the difference between quark and gluon jet energy loss. We expect that our results will be particularly relevant for quantifying the energy loss of quark and gluon jets that propagate through hot or cold nuclear matter.

scholarly journals Bi-Spectral Infrared Algorithm for Cloud Coverage over Oceans by the JEM-EUSO Mission Program

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6506
Author(s):  
David Santalices ◽  
Susana Briz ◽  
Antonio J. de Castro ◽  
Fernando López
Keyword(s):  
Brightness Temperature ◽  
Ad Hoc ◽  
Low Cost ◽  
Infrared Camera ◽  
Cosmic Ray ◽  
High Energy ◽  
Ir Camera ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
The Difference ◽  
Split Window Algorithm

The need to monitor specific areas for different applications requires high spatial and temporal resolution. This need has led to the proliferation of ad hoc systems on board nanosatellites, drones, etc. These systems require low cost, low power consumption, and low weight. The work we present follows this trend. Specifically, this article evaluates a method to determine the cloud map from the images provided by a simple bi-spectral infrared camera within the framework of JEM-EUSO (The Joint Experiment Missions-Extrem Universe Space Observatory). This program involves different experiments whose aim is determining properties of Ultra-High Energy Cosmic Ray (UHECR) via the detection of atmospheric fluorescence light. Since some of those projects use UV instruments on board space platforms, they require knowledge of the cloudiness state in the FoV of the instrument. For that reason, some systems will include an infrared (IR) camera. This study presents a test to generate a binary cloudiness mask (CM) over the ocean, employing bi-spectral IR data. The database is created from Moderate-Resolution Imaging Spectroradiometer (MODIS) data (bands 31 and 32). The CM is based on a split-window algorithm. It uses an estimation of the brightness temperature calculated from a statistical study of an IR images database along with an ancillary sea surface temperature. This statistical procedure to obtain the estimate of the brightness temperature is one of the novel contributions of this work. The difference between the measured and estimation of the brightness temperature determines whether a pixel is cover or clear. That classification requires defining several thresholds which depend on the scenarios. The procedure for determining those thresholds is also novel. Then, the results of the algorithm are compared with the MODIS CM. The agreement is above 90%. The performance of the proposed CM is similar to that of other studies. The validation also shows that cloud edges concentrate the vast majority of discrepancies with the MODIS CM. The relatively high accuracy of the algorithm is a relevant result for the JEM-EUSO program. Further work will combine the proposed algorithm with complementary studies in the framework of JEM-EUSO to reinforce the CM above the cloud edges.

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.

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