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.

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.

scholarly journals Tidal Force of Sun Due to Planetary Radial Alignment and Sun-Spot Cycle

1993 ◽  
Vol 132 ◽  
pp. 407-414
Author(s):  
S.D. Verma
Keyword(s):  
Sunspot Number ◽  
Solar Flares ◽  
Tidal Force ◽  
Solar Photosphere ◽  
Neutral Atmosphere ◽  
The Sun ◽  
Cycle Number ◽  
Long Time ◽  
Small Force ◽  
Periodic Changes

AbstractIt is well known that the Sun’s radiation and a large number of phenomena occurring on the sun have influence on the Earth’s near environment i.e. Atmosphere, Ionosphere, Magnetosphere, etc. These manifest themselves as day-night, seasons, tides and many changes in the neutral atmosphere; changes in meteorological parameters. These changes are directly or indirectly related to variations in solar parameters, such as solar flares, magnetic storms, variations in sunspot number occurring in solar photosphere. Sunsports are observed, their number counted and their accurate records maintained for long time (many centuaries). The sunspot number seems to follow periodic changes with several periods; mainly 11 years and 23.5 years. Recently it has been shown that the combined tidal force of the inner planets and two largest planets, Jupiter and Saturn, have periodic change of 11 and 23.5 years. It was proposed that this small force may be having a tiny influence on the surface of the Sun and causing some nonlinear effect which results into formation of sunspots and thus causes the variations in the number of sunspots. In the present work it is shown that whenever the combined tidal force on sun increases then sunspot number seems to increase and when force decreases sunspot number decreases. This is shown for Solar Cycle number 21.

High-Energy Solar Gamma-Ray Observations

1998 ◽  
Vol 11 (2) ◽  
pp. 755-758
Author(s):  
M. Yoshimori ◽  
N. Saita ◽  
A. Shiozawa
Keyword(s):  
Particle Acceleration ◽  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
Solar Maximum ◽  
High Energy ◽  
The Sun ◽  
Long Duration ◽  
New Findings ◽  
Gamma Ray Emission

In the last solar maximum, gamma-rays associated with solar flares were observed with GRANAT, GAMMA-1, CGRO and YOHKOH. The gamma-ray energies ranged from 100 keV to a few GeV. We obtained several new findings of gamma-ray emission on the Sun: (1) Gamma-ray production in the corona, (2) GeV gamma-ray production in very long duration flares, (3) Electron-rich flares, (4) Gamma-ray lines and solar atmospheric abundances and (5) Possible location of gamma-ray emission. We present the observations of these new findings and discuss high energy phenomena relating to particle acceleration and gamma-ray production during solar flares.

The spectrum of γ rays in the energy range 1011 to 1013 eV at an atmospheric depth of 200 g/cm2, and pion generation in high-energy nucleon interactions

1968 ◽  
Vol 46 (10) ◽  
pp. S700-S705 ◽  
Author(s):  
A. V. Apanasenko ◽  
L. T. Baradzei ◽  
E. A. Kanevskaya ◽  
V. V. Rykov ◽  
Yu. A. Smorodin ◽  
...  
Keyword(s):  
Energy Range ◽  
High Energy ◽  
Nucleon Interaction ◽  
Nuclear Emulsions ◽  
X Ray ◽  
Black Spots ◽  
Γ Rays ◽  
Γ Ray ◽  
Using Data ◽  
Electron Photon

The problem of the existence of a change of slope in the γ-ray spectrum in the atmosphere is of considerable interest in connection with conclusions about the change in the character of the nucleon interaction. Up to now this problem has not been solved experimentally. In this report the γ-ray spectrum in the 1011–1013 eV energy range has been obtained using data from X-ray films and nuclear emulsions exposed on board an airplane at a pressure of 200 g/cm2. The total exposure was 425 hours∙m2. The energies of the electron–photon cascades initiated by γ rays were determined in the X-ray films by measuring the photometric densities of the black spots, and in nuclear emulsions by counting the electron tracks near the cascade axis. The integral spectrum has a power-law form with an exponent of 1.7–1.9. A change in slope in the spectrum was not found. Thus, a mechanism generating pions with energies proportional to the initial nucleon energies exists up to nucleon energies of ~1014 eV. The analysis of the accompaniment of γ rays by "families" shows that in one-third of the cases the energy of the most energetic π0 meson is at least five times that of the next π0 meson. In the remaining two-thirds of the cases the π0 mesons have comparable energies.

scholarly journals Solar flares observed simultaneously with SphinX, GOES and RHESSI

2012 ◽  
Vol 8 (S294) ◽  
pp. 571-572 ◽  
Author(s):  
Tomasz Mrozek ◽  
Szymon Gburek ◽  
Marek Siarkowski ◽  
Barbara Sylwester ◽  
Janusz Sylwester ◽  
...  
Keyword(s):  
Energy Range ◽  
Solar Flares ◽  
Solar Minimum ◽  
Spectroscopic Analysis ◽  
High Energy ◽  
Pin Diode ◽  
X Rays ◽  
X Ray ◽  
Thermal Part ◽  
Silicon Pin Diode

AbstractIn February 2009, during recent deepest solar minimum, Polish Solar Photometer in X-rays (SphinX) begun observations of the Sun in the energy range of 1.2–15 keV. SphinX was almost 100 times more sensitive than GOES X-ray Sensors. The silicon PIN diode detectors used in the experiment were carefully calibrated on the ground using Synchrotron Radiation Source BESSY II. The SphinX energy range overlaps with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) energy range. The instrument provided us with observations of hundreds of very small flares and X-ray brightenings. We have chosen a group of solar flares observed simultaneously with GOES, SphinX and RHESSI and performed spectroscopic analysis of observations wherever possible. The analysis of thermal part of the spectra showed that SphinX is a very sensitive complementary observatory for RHESSI and GOES.

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.

scholarly journals The First Results from “Solar X-ray Spectrometer (SOXS)” Mission

2005 ◽  
Vol 13 ◽  
pp. 622-622 ◽  
Author(s):  
Rajmal Jain ◽  
Hemant Dave ◽  
P. Sreekumar ◽  
A. B. Shah ◽  
N. M. Vadher ◽  
...  
Keyword(s):  
Solid State ◽  
Solar Flare ◽  
Energy Range ◽  
Solar Flares ◽  
High Energy ◽  
Low Energy ◽  
Energy Detector ◽  
X Ray ◽  
Phoswich Detector ◽  
First Results

Abstract“Solar X-ray Spectrometer (SOXS)” mission on-board GSAT-2 Indian spacecraft was launched on 08 May 2003 by GSLV-D2 and deployed in geostationery orbit to study the X-ray emission from solar flares with high spectral and temporal resolution. The SOXS consists of two independent payloads viz. SOXS Low Energy Detector (SLD) payload, and SOXS High Energy Detector (SHD) payload. The SLD consists of two solid state detectors Si PIN and CZT, which cover the energy range from 4-60 keV, while the SHD has NaI(Tl)/CsI(Na) sandwiched phoswich detector that covers energy range from 20 keV to 10 MeV. We present very briefly the science objectives and instrumentation of SLD payload. After the successful In-orbit Tests (IOT), the first light was fed into SLD payload on 08 June 2003 when the solar flare was already in progress. We briefly present the first results from the SLD payload.

scholarly journals Solar Dynamical Processes II

2019 ◽  
Vol 6 (1) ◽  
pp. 1-13
Author(s):  
Ashish Mishra ◽  
Mukul Kumar
Keyword(s):  
Space Weather ◽  
Coronal Mass Ejections ◽  
Solar Flares ◽  
Interplanetary Space ◽  
Coronal Holes ◽  
High Energy ◽  
Small Scale ◽  
The Sun ◽  
Dynamical Processes ◽  
Wide Range

The present article is the successor of Solar Dynamical Processes I. The previous article was focused on the Sun, its magnetic field with an emphasis on various dynamical processes occurring on the Sun, e.g. sunspots, prominence and bright points which in turn plays a fundamental role in regulating the space weather. This article is emphasized on the solar dynamical processes and develop an extensive understanding of the various phenomena involved in their origin. The article also covers various models and hypothesis put forward by pioneer scientists on the basis of their observation by space-borne and ground-based instruments. This article shade light over a wide range of dynamical processes e.g., solar flares, coronal mass ejections, solar jets and coronal holes. Solar jets, the small-scale transient activities are found to have association with the other transient activities (e.g., mini-flares and mini-filaments). Flares as well as the coronal mass ejections are responsible for releasing a large amount of high energy charged particles and magnetic flux into the interplanetary space, and are being considered as the main drivers of space weather.

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