scholarly journals Measurement of Energy Spectrum and Elemental Composition of PeV Cosmic Rays: Open Problems and Prospects

2022 ◽  
Vol 12 (2) ◽  
pp. 705
Author(s):  
Giuseppe Di Sciascio
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
Ground Level ◽  
Galactic Cosmic Rays ◽  
Particle Energy ◽  
Open Problems ◽  
Indirect Measurements ◽  
Air Shower ◽  
Systematic Uncertainties

Cosmic rays represent one of the most important energy transformation processes of the universe. They bring information about the surrounding universe, our galaxy, and very probably also the extragalactic space, at least at the highest observed energies. More than one century after their discovery, we have no definitive models yet about the origin, acceleration and propagation processes of the radiation. The main reason is that there are still significant discrepancies among the results obtained by different experiments located at ground level, probably due to unknown systematic uncertainties affecting the measurements. In this document, we will focus on the detection of galactic cosmic rays from ground with air shower arrays up to 1018 eV. The aim of this paper is to discuss the conflicting results in the 1015 eV energy range and the perspectives to clarify the origin of the so-called `knee’ in the all-particle energy spectrum, crucial to give a solid basis for models up to the end of the cosmic ray spectrum. We will provide elements useful to understand the basic techniques used in reconstructing primary particle characteristics (energy, mass, and arrival direction) from the ground, and to show why indirect measurements are difficult and results are still conflicting.

scholarly journals Short- and Medium-Term Induced Ionization in the Earth Atmosphere by Galactic and Solar Cosmic Rays

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Alexander Mishev
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
Ground Level ◽  
Galactic Cosmic Rays ◽  
Earth Atmosphere ◽  
Medium Term ◽  
Ground Level Enhancement ◽  
Solar Cosmic Rays ◽  
The Earth ◽  
Ionization Effect

The galactic cosmic rays are the main source of ionization in the troposphere of the Earth. Solar energetic particles of MeV energies cause an excess of ionization in the atmosphere, specifically over polar caps. The ionization effect during the major ground level enhancement 69 on January 20, 2005 is studied at various time scales. The estimation of ion rate is based on a recent numerical model for cosmic-ray-induced ionization. The ionization effect in the Earth atmosphere is obtained on the basis of solar proton energy spectra, reconstructed from GOES 11 measurements and subsequent full Monte Carlo simulation of cosmic-ray-induced atmospheric cascade. The evolution of atmospheric cascade is performed with CORSIKA 6.990 code using FLUKA 2011 and QGSJET II hadron interaction models. The atmospheric ion rate is explicitly obtained for various latitudes, namely, 40°N, 60°N and 80°N. The time evolution of obtained ion rates is presented. The short- and medium-term ionization effect is compared with the average effect due to galactic cosmic rays. It is demonstrated that ionization effect is significant only in subpolar and polar atmosphere during the major ground level enhancement of January 20, 2005. It is negative in troposphere at midlatitude, because of the accompanying Forbush effect.

The change in the energy spectrum of galactic cosmic rays over the 11-year solar activity cycle

1968 ◽  
Vol 46 (10) ◽  
pp. S927-S929
Author(s):  
Yu. Stozhkov ◽  
T. N. Charakhchyan
Keyword(s):  
Diffusion Coefficient ◽  
Solar Activity ◽  
Energy Spectrum ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
Activity Cycle ◽  
Solar Activity Cycle ◽  
Galactic Cosmic Rays ◽  
Ray Diffusion

The energy spectrum of galactic cosmic rays has been investigated for various periods of the solar activity. In the framework of commonly used ideas about the mechanism of the 11-year variation according to Parker the dependence of the cosmic-ray diffusion coefficient, D, on the particle rigidity, P, was determined. For the form D ≈ vpα the parameter α is found to change during the cycle of the solar activity.[Formula: see text]

scholarly journals Cosmic Ray Energy Spectrum derived from the Data of EAS Cherenkov Light Arrays in the Tunka Valley

2019 ◽  
Vol 210 ◽  
pp. 01003
Author(s):  
V. Prosin ◽  
I. Astapov ◽  
P. Bezyazeekov ◽  
A. Borodin ◽  
M. Brückner ◽  
...  
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Energy Range ◽  
Cosmic Ray ◽  
Cherenkov Light ◽  
Differential Energy Spectrum ◽  
Extensive Air Shower ◽  
Air Shower

The extensive air shower Cherenkov light array Tunka-133 collected data during 7 winter seasons from 2009 to 2017. From 2175 hours of data taking, we derived the differential energy spectrum of cosmic rays in the energy range 6 · 1015 2 · 1018 eV. The TAIGA-HiSCORE array is in the process of continuous expansion and modernization. Here we present the results obtained with 28 stations of the first HiSCORE stage from 35 clear moonless nights in the winter of 2017-2018. The combined spectrum of two arrays covers a range of 2 · 1014 – 2 · 1018 eV.

OVERVIEW ON DIRECT AND INDIRECT MEASUREMENTS OF COSMIC RAYS

2005 ◽  
Vol 20 (29) ◽  
pp. 6753-6764 ◽  
Author(s):  
JÖRG R. HÖRANDEL
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Galactic Cosmic Rays ◽  
Indirect Measurements

An overview is given on results from direct and indirect measurements of galactic cosmic rays. Their implications on the contemporary understanding of the origin of cosmic rays and the knee in their energy spectrum are discussed.

scholarly journals Solar cosmic rays during the extremely high ground level enhancement on 23 February 1956

2005 ◽  
Vol 23 (6) ◽  
pp. 2281-2291 ◽  
Author(s):  
A. Belov ◽  
E. Eroshenko ◽  
H. Mavromichalaki ◽  
C. Plainaki ◽  
V. Yanke
Keyword(s):  
Cosmic Rays ◽  
Particle Density ◽  
Cosmic Ray ◽  
Ground Level ◽  
Particle Energy ◽  
Ground Level Enhancement ◽  
Solar Cosmic Rays ◽  
Solar Particle ◽  
Small Width ◽  
Standard Design

Abstract. The 23 February 1956 ground level enhancement of the solar cosmic ray intensity (GLE05) is the most famous among the proton events observed since 1942. But we do not have a great deal of information on this event due to the absence of solar wind and interplanetary magnetic field measurements at that time. Furthermore, there were no X-Ray or gamma observations and the information on the associated flare is limited. Cosmic ray data was obtained exclusively by ground level detectors of small size and in some cases of a non-standard design. In the present work all available data from neutron monitors operating in 1956 were analyzed, in order to develop a model of the solar cosmic ray behavior during the event. The time-dependent characteristics of the cosmic ray energy spectrum, cosmic ray anisotropy, and differential and integral fluxes have been evaluated utilizing different isotropic and anisotropic models. It is shown that the most outstanding features of this proton enhancement were a narrow and extremely intense beam of ultra-relativistic particles arriving at Earth just after the onset and the unusually high maximum solar particle energy. However, the contribution of this beam to the overall solar particle density and fluency was not significant because of its very short duration and small width. Our estimate of the integral flux for particles with energies over 100 MeV places this event above all subsequent. Perhaps the number of accelerated low energy particles was closer to a record value, but these particles passed mainly to the west of Earth. Many features of this GLE are apparently explained by the peculiarity of the particle interplanetary propagation from a remote (near the limb) source. The quality of the available neutron monitor data does not allow us to be certain of some details; these may be cleared up by the incorporation into the analysis of data from muonic telescopes and ionization chambers operating at that time. Keywords. Interplanatary physics (Cosmic rays; Energetic particles) – Solar physics, astrophysics and astronomy (Flares and mass injections)

scholarly journals COSMIC RAYS FROM THE KNEE TO THE SECOND KNEE: 1014 TO 1018eV

2007 ◽  
Vol 22 (21) ◽  
pp. 1533-1551 ◽  
Author(s):  
JÖRG R. HÖRANDEL
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Energy Region ◽  
High Energy ◽  
Particle Energy ◽  
Air Showers ◽  
Air Shower ◽  
Wide Range ◽  
High Energy Particles

The energies of cosmic rays, fully ionized charged nuclei, extend over a wide range up to 1020 eV. A particularly interesting energy region spans from 1014 to 1018 eV, where the all-particle energy spectrum exhibits two interesting structures, the "knee" and the "second knee". An explanation of these features is thought to be an important step in understanding the origin of the high-energy particles. Recent results of air shower experiments in this region are discussed. Special attention is drawn to explain the principle of air shower measurements — a simple Heitler model of (hadronic) air showers is developed.

Gradient of galactic cosmic rays normal to the solar equatorial plane

1968 ◽  
Vol 46 (10) ◽  
pp. S981-S984 ◽  
Author(s):  
D. Patel ◽  
V. Sababhai ◽  
G. Subramanian
Keyword(s):  
Magnetic Field ◽  
Energy Spectrum ◽  
Cosmic Rays ◽  
Interplanetary Magnetic Field ◽  
Equatorial Plane ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Cosmic Ray Intensity ◽  
Positive Exponent ◽  
Ray Density

Predictions concerning the anisotropy of galactic cosmic rays due to a gradient of cosmic-ray density perpendicular to the solar equatorial plane have been verified experimentally as follows. (1) The energy spectrum of the variation of the semidiurnal component has a positive exponent. (2) The diurnal and the semidiurnal components are oriented with respect to the interplanetary magnetic field. (3) A deficiency of cosmic-ray intensity, Tmin, is observed along the direction of the interplanetary magnetic field on days when the energy spectrum of the diurnal variation has an exponent different from zero.

Cosmic rays at ground level; a brief introduction

2021 ◽  
Author(s):  
Du Toit Strauss
Keyword(s):  
Cosmic Rays ◽  
Primary Particle ◽  
Secondary Particle ◽  
Cosmic Ray ◽  
Ground Level ◽  
High Energy ◽  
Galactic Cosmic Rays ◽  
Neutron Monitors ◽  
The Earth

<p>Galactic cosmic rays, and sporadic high energy solar energetic particles, are energetic enough to pierce the Earth’s protective magnetosphere and interact with the atmosphere. Here, a secondary particle cascade leads to enhanced radiation levels which is of importance, for instance, to aviation dosimetry and related studies. At ground level, these secondary particles can be observed (indirectly) by means of neutron monitors, and this has been done for more than 70 years, providing a valuable long-term cosmic ray record. In this talk, we introduce the different primary particle populations, discuss their acceleration and modulation, and connect this with long-term neutron monitor measurements.</p>

scholarly journals Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

2019 ◽  
Vol 5 (9) ◽  
pp. eaax3793 ◽  
Author(s):  
◽  
Q. An ◽  
R. Asfandiyarov ◽  
P. Azzarello ◽  
P. Bernardini ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Cosmic Radiation ◽  
Precise Measurement ◽  
Milky Way ◽  
Spectral Feature ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Proton Spectrum ◽  
First Time

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 1/2 years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

Atmospheric production and transport of 7Be activity by cosmic rays: Modelling with the chemistry-climate model SOCOLv3.0 and comparison with direct measurements

2021 ◽  
Author(s):  
Kseniia Golubenko ◽  
Eugene Rozanov ◽  
Genady Kovaltsov ◽  
Ari-Pekka Leppänen ◽  
Ilya Usoskin
Keyword(s):  
Cosmic Rays ◽  
Climate Changes ◽  
Climate Model ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Cosmogenic Isotopes ◽  
Cosmogenic Isotope ◽  
The Past ◽  
Direct Measurements ◽  
First Results

<p>We present the first results of modelling of the short-living cosmogenic isotope <sup>7</sup>Be production, deposition, and transport using the chemistry-climate model SOCOLv<sub>3.0</sub> aimed to study solar-terrestrial interactions and climate changes. We implemented an interactive deposition scheme,  based on gas tracers with and without nudging to the known meteorological fields. Production of <sup>7</sup>Be was modelled using the 3D time-dependent Cosmic Ray induced Atmospheric Cascade (CRAC) model. The simulations were compared with the real concentrations (activity) and depositions measurements of <sup>7</sup>Be in the air and water at Finnish stations. We have successfully reproduced and estimated the variability of the cosmogenic isotope <sup>7</sup>Be produced by the galactic cosmic rays (GCR) on time scales longer than about a month, for the period of 2002–2008. The agreement between the modelled and measured data is very good (within 12%) providing a solid validation for the ability of the SOCOL CCM to reliably model production, transport, and deposition of cosmogenic isotopes, which is needed for precise studies of cosmic-ray variability in the past. </p>

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