scholarly journals Estimation of the mean energy of cosmic ray muons in multilayer detectors

1996 ◽  
Vol 381 (1) ◽  
pp. 73-78
Author(s):  
T.T. Barnaveli ◽  
Yu.G. Werbetsky ◽  
I.V. Khaldeeva ◽  
N.A. Eristavi
Keyword(s):  
Cosmic Ray ◽  
The Mean

scholarly journals A Novel Lithium Foil Cosmic-Ray Neutron Detector for Measuring Field-Scale Soil Moisture

2021 ◽  
Vol 3 ◽  
Author(s):  
Andres Patrignani ◽  
Tyson E. Ochsner ◽  
Benjamin Montag ◽  
Steven Bellinger
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Atmospheric Pressure ◽  
Lower Cost ◽  
Cosmic Ray ◽  
Absolute Difference ◽  
Atmospheric Conditions ◽  
Volumetric Soil Water Content ◽  
The Mean

During the past decade, cosmic-ray neutron sensing technology has enabled researchers to reveal soil moisture spatial patterns and to estimate landscape-average soil moisture for hydrological and agricultural applications. However, reliance on rare materials such as helium-3 increases the cost of cosmic-ray neutron probes (CRNPs) and limits the adoption of this unique technology beyond the realm of academic research. In this study, we evaluated a novel lower cost CRNP based on moderated ultra-thin lithium-6 foil (Li foil system) technology against a commercially-available CRNP based on BF3 (boron trifluoride, BF-3 system). The study was conducted in a cropped field located in the Konza Prairie Biological Station near Manhattan, Kansas, USA (325 m a.s.l.) from 10 April 2020 to 18 June 2020. During this period the mean atmospheric pressure was 977 kPa, the mean air relative humidity was 70%, and the average volumetric soil water content was 0.277 m3 m−3. Raw fast neutron counts were corrected for atmospheric pressure, atmospheric water vapor, and incoming neutron flux. Calibration of the CRNPs was conducted using four intensive field surveys (n > 120), in combination with continuous observations from an existing array of in situ soil moisture sensors. The time series of uncorrected neutron counts of the Li foil system was highly correlated (r2 = 0.91) to that of the BF-3 system. The Li foil system had an average of 2,250 corrected neutron counts per hour with an uncertainty of 2.25%, values that are specific to the instrument size, detector configuration, and atmospheric conditions. The estimated volumetric water content from the Li foil system had a mean absolute difference of 0.022 m3 m−3 compared to the value from the array of in situ sensors. The new Li foil detector offers a promising lower cost alternative to existing cosmic-ray neutron detection devices used for hectometer-scale soil moisture monitoring.

V. Studies of cosmic ray neutrino interactions in the Kolar Gold Field experiment

1967 ◽  
Vol 301 (1465) ◽  
pp. 137-157 ◽  
Keyword(s):  
Field Experiment ◽  
Cosmic Radiation ◽  
Cosmic Ray ◽  
Surrounding Rock ◽  
Standard Rock ◽  
Neutrino Interactions ◽  
Experimental Programme ◽  
Measured Rate ◽  
Deep Underground ◽  
The Mean

Results are presented of an experiment to study the penetrating particles in the cosmic radiation deep underground, at a depth of 7500 m. w. e. (standard rock). The events recorded are attributable, in the main, to muons produced either in the atmosphere or by the interactions of neutrinos in the surrounding rock. The muons have been studied in some detail and it appears that the mean energy of the neutrino induced muons (probably less than about 30 GeV) is low compared with that of the muons of atmospheric origin. The significance of the celestial coordinates of the muons and the measured rate of neutrino- induced muons is discussed and the future experimental programme is indicated.

scholarly journals Molecular Clouds and Star Formation at Large R

1991 ◽  
Vol 144 ◽  
pp. 121-130
Author(s):  
J. Brand ◽  
J.G.A. Wouterloot
Keyword(s):  
Star Formation ◽  
Molecular Clouds ◽  
Density Wave ◽  
Cosmic Ray ◽  
Volume Density ◽  
Kinetic Temperature ◽  
Galactocentric Distance ◽  
The Galaxy ◽  
The Mean ◽  
Cosmic Ray Flux

In the outer Galaxy (defined here as those parts of our system with galactocentric radii R>R0) the HI gas density (Wouterloot et al., 1990), the cosmic ray flux (Bloemen et al, 1984) and the metallicity (Shaver et al., 1983) are lower than in the inner parts. Also, the effect of a spiral density wave is much reduced in the outer parts of the Galaxy due to corotation. This changing environment might be expected to have its influence on the formation of molecular clouds and on star formation within them. In fact, some differences with respect to the inner Galaxy have been found: the ratio of HI to H2 surface density is increasing from about 5 near the Sun to about 100 at R≈20kpc (Wouterloot et al., 1990). Because of the “flaring” of the gaseous disk, the scale height of both the atomic and the molecular gas increases by about a factor of 3 between R0 and 2R0 (Wouterloot et al., 1990), so the mean volume density of both constituents decreases even more rapidly than their surface densities. The size of HII regions decreases significantly with increasing galactocentric distance (Fich and Blitz, 1984), probably due to the fact that outer Galaxy clouds are less massive (see section 3.3), and therefore form fewer O-type stars than their inner Galaxy counter parts. There are indications that the cloud kinetic temperature is lower by a few degrees (Mead and Kutner, 1988), although it is not clear to what extent this is caused by beam dilution.

EFFECTS OF FLIGHT ROUTE VARIATION AND GREAT-CIRCLE APPROXIMATION ON AVIATION DOSE ASSESSMENT FOR POPULAR FLIGHTS FROM TAIWAN

2018 ◽  
Vol 184 (1) ◽  
pp. 79-89 ◽  
Author(s):  
Zi-Yi Yang ◽  
Rong-Jiun Sheu
Keyword(s):  
Cosmic Ray ◽  
Mean Value ◽  
Great Circle ◽  
Dose Assessment ◽  
Tracking Data ◽  
Secondary Particles ◽  
The Mean ◽  
Flight Route ◽  
Airline Crews ◽  
Galactic Cosmic Ray

Abstract Galactic cosmic-ray-induced secondary particles in the atmosphere constitute an important source of radiation exposure to airline crews and passengers. In this study, a systematic dose assessment was conducted for 11 popular flights from Taiwan, with an emphasis on the effects of flight route variation and assumption. The case studies covered a broad range of commercial flights departing from Taipei, from a domestic flight of <1 h to a long-haul international flight of more than 14 h. For each route under study, information on 100 actual flight routes was retrieved from flight tracking data collected from June to September 2017, and the information was analyzed using a self-developed program called the ‘NTHU Flight Dose Calculator’. The resulting distribution of route doses provided not only the mean value and associated standard deviation but also information on the characteristics of aviation dose assessment and management. Furthermore, compared with actual flight routes, the dose differences introduced by great-circle approximation were evaluated, and the effects of solar activity on the dose assessment of these flights were reported.

ATMOSPHERIC CONTRIBUTION TO THE DIURNAL VARIATION OF THE COSMIC-RAY MESON INTENSITY AT DEEP RIVER

1966 ◽  
Vol 44 (6) ◽  
pp. 1329-1347 ◽  
Author(s):  
M. Bercovitch
Keyword(s):  
Diurnal Variation ◽  
Neutron Monitor ◽  
Cosmic Ray ◽  
Ground Level ◽  
Barometric Pressure ◽  
Atmospheric Temperature ◽  
The Mean ◽  
Variation Vector ◽  
Best Fit ◽  
Ground Level Air

We have established the correlation between the atmospheric temperature contribution to the diurnal variation observed by a meson monitor at Deep River and the diurnal variation of two easily and continuously observable atmospheric variables, the ground-level air temperature and the barometric pressure. The atmospheric meson diurnal variation vector is taken to be, on a statistical basis, A = M−RN, where M and N represent the observed meson-monitor and neutron-monitor diurnal variations and R is the factor of proportionality between the meson and neutron monitor responses to the primary anisotropy. It is found that A is proportional in amplitude to T, the ground-level temperature diurnal variation, and, further, that T and the barometric-pressure diurnal variation P are proportional in amplitude. The "best-fit" representation of A in terms of T and P is determined by minimizing the mean-square deviation between the daily vectors RN and (M−A). Where A = CtT + CpP, the best fit occurs when Ct = −0.0052%/ °C, Cp = 0.038%/mb, R = 0.47, and the phase of T is shifted by + 1.0 hour. These values apply to Deep River, where the original hourly meson data have been barometer-corrected using a coefficient of 0.16%/mb.

Cosmic-ray streaming perpendicular to the mean magnetic field

1978 ◽  
Vol 53 (2) ◽  
pp. 507-513 ◽  
Author(s):  
M. A. Forman ◽  
J. R. Jokipii
Keyword(s):  
Magnetic Field ◽  
Cosmic Ray ◽  
The Mean

Sea-level cosmic ray spectra at large zenith angles

1961 ◽  
Vol 265 (1320) ◽  
pp. 117-132 ◽  
Keyword(s):  
Sea Level ◽  
Meson Production ◽  
Cosmic Ray ◽  
Great Accuracy ◽  
Statistical Fluctuation ◽  
Momentum Range ◽  
Production Spectrum ◽  
A Value ◽  
The Mean ◽  
Particle Intensity

Measurements have been made at Durham (200ft. above sea level) with an emulsion spectrograph of the absolute cosmic ray particle intensity in the momentum range 1 to 100 GeV/ c at zenith angles of between 65° and 85°. It is found that a differential π-meson production spectrum of the form I 0 E -y fits closely the present results as well as the accepted vertical spectrum. The values of the parameters when E lies between 6 and 1000 GeV are given by the equations I 0 = 0.425 — 01.25 log 10 E and y = 3.92 — 0.944 (1 — 0.125 log 10 E ) -1 and their approximate constant values in this range are 0T5 and 2*55 respectively. The analysis is based on the model of Barrett, Bollinger, Cocconi, Eisenberg & Greisen (1952) but, in addition, the effects of scattering and geomagnetic deflexion of u-mesons in the atmosphere have been taken into account as well as their production over a range of atmospheric depths. Although in principle it should be possible from the form of the sea-level spectra at large zenith angles to determine the relative numbers of π- and K -mesons at production, it is shown that very great accuracy is required in order to do so. Nevertheless, the agreement between the theoretical curves and the experimental measurements indicates that the main assumptions concerning the production and propagation of mesons in the atmosphere are correct. The mean positive to negative ratio is 1.39±0.08, a value rather larger than is found by other observers at 68°, but within statistical fluctuation.

scholarly journals Strangeness Enhancement at LHC Energies Using the Thermal Model and EPOSLHC Event Generator

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mahmoud Hanafy ◽  
Omnia S. A. Qandil ◽  
Asmaa G. Shalaby
Keyword(s):  
Cosmic Ray ◽  
Heavy Ion ◽  
Event Generator ◽  
Relativistic Heavy Ion Collider ◽  
Model Calculations ◽  
High Energies ◽  
Particle Ratios ◽  
Strangeness Enhancement ◽  
The Mean ◽  
Good Agreement

The strangeness enhancement signature of QGP formation at LHC energies is carefully tackled in the present study. Based on HRG, the particle ratios of mainly strange and multistrange particles are studied at energies from lower s ~ 0.001 up to 13 TeV. The strangeness enhancement clearly appeared at more high energies, and the ratios are confronted to the available experimental data. The particle ratios are also studied using the Cosmic Ray Monte Carlo (CRMC) interface model with its two different event generators, namely, EPOS 1.99 and EPOSlhc, which show a good agreement with the model calculations at the whole range of the energy. We utilize them to produce some particles ratios. EPOS 1.99 is used to estimate particle ratios at lower energies from AGS up to the Relativistic Heavy Ion Collider (RHIC) while EPOSlhc is used at LHC energies. The production of kaons and lambda particles is studied in terms of the mean multiplicity in p-p collisions at energies ranging from 4 to 26 GeV. We find that both HRG model and the used event generators, EPOS 1.99 and EPOSlhc, can describe the particle ratios very well. Additionally, the freeze-out parameters are estimated for different collision systems, such as p-p and Pb-Pb, at LHC energies using both models.

The search for cosmic-ray anisotropies

1975 ◽  
Vol 277 (1270) ◽  
pp. 381-393 ◽  
Keyword(s):  
Magnetic Field ◽  
Cosmic Ray ◽  
Interstellar Space ◽  
Galactic Rotation ◽  
Cosmic Ray Intensity ◽  
Solar Motion ◽  
Upper Limits ◽  
The Mean ◽  
High Degree ◽  
Small Anisotropy

At the present time there is no generally accepted evidence for any statistically significant anisotropy in the energy range 1017-1019 eV. The upper limits on the possible anisotropy provide strong evidence that these particles are extra-galactic. In that part of the cosmic-ray magnetic rigidity spectrum below ca . 2 x 1011 V the interplanetary magnetic field effectively prevents the detection of anisotropies in interstellar space and the only isotropies measured are associated with the solar wind and its associated magnetic field. In the range of magnetic rigidities extending from 1011 to 1012 V the cosmic-ray intensity shows evidence for a small anisotropy of about 2 x 10~4 which can be explained as the result of solar motion relative to the average galactic rotation in our neighbourhood. When this is removed the residual deviations from the mean intensity preclude any systematic sinusoidal variation greater than 2 x 10~4. This high degree of isotropy is most easily understood if these particles are members of an extra-galactic population and it is suggested that this extra-galactic component predominates from the highest cosmic-ray energies down the spectrum at least as far as ca . 1011 V rigidity.

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