A search for high-energy solar neutrons

1968 ◽  
Vol 46 (10) ◽  
pp. S753-S756 ◽  
Author(s):  
Chang Y. Kim
Keyword(s):  
Cosmic Rays ◽  
Solar Flare ◽  
Sunspot Number ◽  
Energy Region ◽  
High Energy ◽  
The Sun ◽  
Geographic Latitude ◽  
Elastic Collisions ◽  
The Difference

Two stacks of G-5 emulsions on a directional device were exposed to cosmic rays at a ceiling altitude of 114 000 ft on July 30, 1966, at Fort Churchill (geographic latitude 58.8 °N and longitude 94.1° W). An attempt to measure the flux of high-energy solar neutrons has been made by inspecting the difference in flux from the direction of the sun and from the symmetrical direction about the zenith. The flux of neutrons has been determined by making observations on the tracks of protons recoiling from elastic collisions of neutrons with hydrogen nuclei present in the emulsions. The preliminary result of the experiment has shown that in the energy region of 20–100 MeV an excess of 1.1 × 10−2 neutrons cm−2 s−1 from the direction of the sun was observed. On that day the sunspot number was 63, and no major solar flare was reported.

Solar neutron flux in the energy range 20–160 MeV

1970 ◽  
Vol 48 (18) ◽  
pp. 2155-2161 ◽  
Author(s):  
C. Y. Kim
Keyword(s):  
Neutron Flux ◽  
Energy Range ◽  
Sunspot Number ◽  
Solar Flares ◽  
Energy Region ◽  
High Energy ◽  
The Sun ◽  
Solar Neutron ◽  
Nuclear Emulsions ◽  
The Difference

An attempt to measure the flux of high-energy solar neutrons was made by measuring the difference in flux from the direction of the sun and from the symmetrical direction about the zenith, using oriented nuclear emulsions flown by balloon on July 30, 1966 from Fort Churchill, Manitoba.An excess of (2.2 ± 2.5) × 10−2 neutrons cm−2 s−1 was observed from the direction of the sun in the energy region of 20–160 MeV. On the day of the flight the sunspot number was 63, and no major solar flares were reported.

Detection of a change in the North-South ratio of count rates of particles of high-energy cosmic rays during a change in the polarity of the magnetic field of the Sun

JETP Letters ◽  
2015 ◽  
Vol 101 (4) ◽  
pp. 228-231
Author(s):  
A. V. Karelin ◽  
O. Adriani ◽  
G. C. Barbarino ◽  
G. A. Bazilevskaya ◽  
R. Bellotti ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
High Energy ◽  
The Sun ◽  
High Energy Cosmic Rays ◽  
The North ◽  
The Magnetic Field

scholarly journals Cosmic-ray propagation around the Sun: investigating the influence of the solar magnetic field on the cosmic-ray Sun shadow

2020 ◽  
Vol 633 ◽  
pp. A83
Author(s):  
J. Becker Tjus ◽  
P. Desiati ◽  
N. Döpper ◽  
H. Fichtner ◽  
J. Kleimann ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Activity ◽  
Solar Cycle ◽  
Cosmic Rays ◽  
Solar Magnetic Field ◽  
Cosmic Ray ◽  
High Energy ◽  
High Solar Activity ◽  
The Sun ◽  
Theoretical Understanding

The cosmic-ray Sun shadow, which is caused by high-energy charged cosmic rays being blocked and deflected by the Sun and its magnetic field, has been observed by various experiments, such as Argo-YBJ, Tibet, HAWC, and IceCube. Most notably, the shadow’s size and depth was recently shown to correlate with the 11-year solar cycle. The interpretation of such measurements, which help to bridge the gap between solar physics and high-energy particle astrophysics, requires a solid theoretical understanding of cosmic-ray propagation in the coronal magnetic field. It is the aim of this paper to establish theoretical predictions for the cosmic-ray Sun shadow in order to identify observables that can be used to study this link in more detail. To determine the cosmic-ray Sun shadow, we numerically compute trajectories of charged cosmic rays in the energy range of 5−316 TeV for five different mass numbers. We present and analyze the resulting shadow images for protons and iron, as well as for typically measured cosmic-ray compositions. We confirm the observationally established correlation between the magnitude of the shadowing effect and both the mean sunspot number and the polarity of the magnetic field during the solar cycle. We also show that during low solar activity, the Sun’s shadow behaves similarly to that of a dipole, for which we find a non-monotonous dependence on energy. In particular, the shadow can become significantly more pronounced than the geometrical disk expected for a totally unmagnetized Sun. For times of high solar activity, we instead predict the shadow to depend monotonously on energy and to be generally weaker than the geometrical shadow for all tested energies. These effects should become visible in energy-resolved measurements of the Sun shadow, and may in the future become an independent measure for the level of disorder in the solar magnetic field.

High energy gamma-families with halo and mass composition of primary cosmic rays in energy region above 10 PeV

2001 ◽  
Vol 97 (1-3) ◽  
pp. 113-115
Author(s):  
A.S. Borisov ◽  
Z.M. Guseva ◽  
S.A. Karpova ◽  
J. Kempa ◽  
A. Krys ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Energy Region ◽  
High Energy ◽  
Mass Composition ◽  
High Energy Gamma ◽  
Energy Gamma ◽  
Primary Cosmic Rays

scholarly journals The World Neutron Monitor Network as a tool for the study of solar neutrons

1997 ◽  
Vol 15 (4) ◽  
pp. 375-386 ◽  
Author(s):  
I. G. Usoskin ◽  
G. A. Kovaltsov ◽  
H. Kananen ◽  
P. Tanskanen
Keyword(s):  
Solar Flare ◽  
Neutron Monitor ◽  
Event Detection ◽  
High Energy ◽  
The Sun ◽  
Estimation Technique ◽  
Solar Neutron ◽  
The World

Abstract. The use of the World Neutron Monitor Network to detect high-energy solar neutrons is discussed in detail. It is shown that the existing network can be used for the routine detection of intense sporadic solar-neutron events whenever they occur. A technique is suggested involving the weighted summation of responses of separate monitors to solar neutrons. It is demonstrated that the use of this method improves the significance of solar-neutron event detection. Different results of the simulation of the neutron-monitor sensitivity to solar neutrons have been tested with respect to their application for practical use. It is shown that the total number of neutrons with energy above 300 MeV injected from the Sun during a solar flare can be estimated directly from the time-integrated neutron-monitor response to solar neutrons without any model assumptions. The estimation technique has been developed.

The chemical composition of energetic charged particles in interplanetary space

1980 ◽  
Vol 297 (1433) ◽  
pp. 621-627
Keyword(s):  
Chemical Composition ◽  
Cosmic Rays ◽  
Solar Flare ◽  
Charge State ◽  
Interplanetary Space ◽  
Charged Particles ◽  
High Energy ◽  
Galactic Cosmic Rays ◽  
Ionic Charge ◽  
Particle Population

The particle population in the heliosphere is briefly reviewed. Next the chemical composition of the charged fraction is reviewed by discussing three classes. The galactic cosmic rays and high energy solar flare particles above 100 MeV/nucleon are mentioned. The anomalous component in the range 1-100 MeV/nucleon, prompt solar flare particles, energetic storm particles and corotating events are discussed. The anomalous variations in isotopic ( 3 He) and chemical composition (iron-rich events) at energies below 10 MeV are reviewed. A discussion on the ionic charge state of these particles concludes this overview.

ASTROPHYSICAL ASPECTS IN THE STUDIES OF SOLAR COSMIC RAYS

2008 ◽  
Vol 23 (01) ◽  
pp. 1-141 ◽  
Author(s):  
L. I. MIROSHNICHENKO ◽  
J. A. PEREZ-PERAZA
Keyword(s):  
Cosmic Rays ◽  
High Energy ◽  
Solar Proton ◽  
Maximum Energy ◽  
The Sun ◽  
Solar Cosmic Rays ◽  
Frequency Distributions ◽  
Research Fields ◽  
Stellar Flares ◽  
Energy Processes

This review paper comprises main concepts, available observational data and recent theoretical results related to astrophysical aspects of particle acceleration at/near the Sun and extreme capacities of the solar accelerator(s). We summarize underground and ground-based observations of solar cosmic rays (SCR) accumulated since 1942, direct spacecraft measurements of solar energetic particles (SEP) near the Earth's orbit, indirect information on the SCR variations in the past, and other relevant astrophysical, solar and geophysical data. The list of the problems under discussion includes: upper limit spectrum (ULS) for solar cosmic rays; maximum energy (rigidity), Em(Rm), of particles accelerated at/near the Sun; production of the flare neutrinos; energetics of SCR and solar flares; production of flare neutrons and gamma rays; charge states and elemental abundances of accelerated solar ions; coronal mass ejections (CME's) and extended coronal structures in acceleration models; magnetic reconnection in acceleration scenarios; size (frequency) distributions of solar proton events (SPE) and stellar flares; occurrence probability of giant flares; archaeology of solar cosmic rays. The discussion allows us to outline a series of interesting conceptual and physical associations of SCR generation with the high-energy processes at other stars. The most reliable estimates of various parameters are given in each of research fields mentioned above; a set of promising lines of future studies is highlighted. A great importance of SCR data for resolving some general astrophysical problems is emphasized.

Sign in / Sign up

Export Citation Format

Share Document