The 1966–67 increase in solar cosmic-ray activity

1968 ◽  
Vol 46 (10) ◽  
pp. S766-S771 ◽  
Author(s):  
A. J. Masley ◽  
A. D. Goedeke
Keyword(s):  
Geomagnetic Latitude ◽  
Cosmic Ray ◽  
High Energy ◽  
Low Energy ◽  
Neutron Monitors ◽  
Apparent Lack ◽  
Time Profiles ◽  
Delay Times ◽  
Measured Absorption ◽  
Particle Intensity

A significant increase in solar cosmic-ray activity began in early 1966. During the period from March 1966 to June 1967, 14 events were observed. This can be compared to one event in 1964 and one event in 1965. Events in 1966 occurred on 24 March, 7 July, 28 August, 2 September, and 14 September. Events in 1967 include those of 28 January, 2 February, 7 February, 13 February, 11 March, 23 March, 23 May, 28 May, and 6 June.The 2 September 1966 event, reaching a maximum of 13 dB (~105/cm2 s > 2 MeV), was the largest observed since July 1961. The 23 May 1967 event, with 11 dB, reached maximum absorption 35 hours after first observation. The 28 January 1967 event exhibits several interesting features. There is an apparent lack of a visible flare. Low-energy particles were observed for several hours before neutron monitors observed an event in excess of 15%, representing a low-energy precursor to the high-energy event. Details of these events are discussed. Parameters related to acceleration and propagation such as delay times and intensity–time profiles, effects related to other geophysical phenomena, and comparisons with satellite observations are also included. This paper is based on 30-MHz riometer observations at the Douglas Observatories located at McMurdo, Antarctica, and Shepherd Bay, N.W.T., Canada (80° geomagnetic latitude). The measured absorption is proportional to the square root of the particle intensity.

The MACRO Experiment

2003 ◽  
Vol 18 (29) ◽  
pp. 2001-2018 ◽  
Author(s):  
G. Giacomelli ◽  
A. Margiotta
Keyword(s):  
Atmospheric Neutrino ◽  
Cosmic Ray ◽  
High Energy ◽  
Magnetic Monopoles ◽  
Low Energy ◽  
Muon Neutrino ◽  
High Energy Muon ◽  
Upper Limits ◽  
Neutrino Astronomy

In this paper we describe the main results obtained by the MACRO experiment: final stringent upper limits on GUT magnetic monopoles and nuclearites, results on atmospheric neutrino oscillations, high energy muon neutrino astronomy, searches for WIMPs, search for low energy stellar gravitational collapse neutrinos, several studies with high energy downgoing muons and determination of the primary cosmic ray composition at knee energies.

scholarly journals THE TWO TYPES OF CHERENKOV GLUONS AT LHC ENERGIES

2007 ◽  
Vol 16 (10) ◽  
pp. 3108-3114 ◽  
Author(s):  
I. M. DREMIN
Keyword(s):  
Energy Region ◽  
Scattering Amplitude ◽  
Cosmic Ray ◽  
High Energy ◽  
Positive Real Part ◽  
Forward Scattering ◽  
Low Energy ◽  
High Energy Region ◽  
Forward Scattering Amplitude ◽  
Positive Real

Beside comparatively low energy Cherenkov gluons observed at RHIC, there could be high energy gluons at LHC, related to the high energy region of positive real part of the forward scattering amplitude. In both cases they give rise to particles emitted along some cone. The characteristics of the cones produced by these two types of gluons are different. Therefore different experiments are needed to detect them. The cosmic ray event which initiated this idea is described in detail.

scholarly journals e- discrimination at high energy in the JUNO detector

2019 ◽  
Vol 209 ◽  
pp. 01011
Author(s):  
Giulio Settanta ◽  
Stefano Maria Mari ◽  
Cristina Martellini ◽  
Paolo Montini
Keyword(s):  
Neutrino Oscillation ◽  
Liquid Scintillator ◽  
Detection Threshold ◽  
Atmospheric Neutrino ◽  
Neutrino Flux ◽  
Cosmic Ray ◽  
Energy Detection ◽  
High Energy ◽  
Low Energy ◽  
Temporal Behaviour

Cosmic Ray and neutrino oscillation physics can be studied by using atmospheric neutrinos. JUNO (Jiangmen Underground Neutrino Observatory) is a large liquid scintillator detector with low energy detection threshold and excellent energy resolution. The detector performances allow the atmospheric neutrino oscillation measurements. In this work, a discrimination algorithm for different reaction channels of neutrino-nucleon interactions in the JUNO liquid scintillator, in the GeV/sub-GeV energy region, is presented. The atmospheric neutrino flux is taken as reference, considering $\mathop {{v_\mu }}\limits^{( - )} $ and $\mathop {{v_e}}\limits^{( - )} $. The different temporal behaviour of the classes of events have been exploited to build a timeprofile-based discrimination algorithm. The results show a good selection power for $\mathop {{v_e}}\limits^{( - )} $ CC events, while the $\mathop {{v_\mu }}\limits^{( - )} $ CC component suffers of an important contamination from NC events at low energy, which is under study. Preliminary results are presented.

A high-energy increase in cosmic-ray intensity

1991 ◽  
Vol 69 (8-9) ◽  
pp. 984-987
Author(s):  
D. Venkatesan ◽  
A. G. Ananth
Keyword(s):  
Solar Flare ◽  
Cosmic Ray ◽  
High Energy ◽  
Energy Increase ◽  
Neutron Monitors ◽  
Geomagnetic Index ◽  
Cosmic Ray Intensity ◽  
Energy Cutoff ◽  
High Energy Phenomenon ◽  
Interplanetary Disturbance

The increase in cosmic rays observed by neutron monitors with high-energy cutoff, on April 29, 1973, is interpreted to be a definite high-energy phenomenon. This is not associated with any solar flare or interplanetary disturbance. The association of the increase in intensity with geomagnetic index Dst variation indicates a possibility that the high-energy event was caused by a magnetospheric phenomenon.

Two anisotropies of the cosmic-ray particles producing the cosmic-ray diurnal variation

1968 ◽  
Vol 46 (10) ◽  
pp. S828-S830
Author(s):  
Masatoshi Kitamura
Keyword(s):  
Cosmic Rays ◽  
Diurnal Variation ◽  
Interplanetary Space ◽  
Geomagnetic Latitude ◽  
Cosmic Ray ◽  
Diurnal Variations ◽  
Low Energy ◽  
The Other ◽  
Energy Spectra ◽  
Cosmic Ray Intensity

The solar diurnal variations of both meson and nucleon components of cosmic rays at sea level at geomagnetic latitude 57.5° and geomagnetic longitude 0° are analyzed by the model in which two anisotropies of cosmic-ray particles (one of them, Δj1, from about 20 h L.T. and the other, Δj2, from about 8 h L.T. in interplanetary space) produce the solar diurnal variation of the cosmic-ray intensity on the earth.When the energy spectra of Δj1 and Δj2 are represented by [Formula: see text] and [Formula: see text], respectively, where j0(E) is the normal energy spectrum of the primary cosmic rays, it is shown that the evaluation for m1 = 1, 2, m2 = 0 and the cutoffs at 8 and 10 BeV on the low-energy side of spectra of both Δj1 and Δj2 agree well with the observational results at Deep River.

scholarly journals Latest Cosmic Ray Results from IceTop and IceCube

2019 ◽  
Vol 210 ◽  
pp. 03005
Author(s):  
Karen Andeen ◽  
Matthias Plum
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Low Energy ◽  
South Pole ◽  
Air Showers ◽  
Future Plans

The IceCube Neutrino Observatory at the geographic South Pole, with its surface array IceTop, detects three different components of extensive air showers: the total signal at the surface, low energy muons on the periphery of the showers, and high energy muons in the deep In Ice array of IceCube. These measurements enable determination of the energy spectrum and composition of cosmic rays from PeV to EeV energies, the anisotropy in the distribution of cosmic ray arrival directions, the muon density of cosmic ray air showers, and the PeV gamma-ray flux. Furthermore, IceTop can be used as a veto for the neutrino measurements. The latest results from these IceTop analyses will be presented along with future plans.

The muon spectra near the geomagnetic equator

1968 ◽  
Vol 46 (10) ◽  
pp. S301-S305 ◽  
Author(s):  
O. C. Allkofer ◽  
R. D. Andresen ◽  
W. D. Dau
Keyword(s):  
Integral Intensity ◽  
Geomagnetic Latitude ◽  
Cosmic Ray ◽  
Momentum Spectrum ◽  
Low Energy ◽  
Charge Ratio ◽  
Theoretical Spectrum ◽  
Measured Spectrum ◽  
Geomagnetic Equator ◽  
Chamber Technique

The vertical momentum spectrum and the charge ratio of cosmic-ray muons have been investigated in the range 0.3–25 GeV/c at a geomagnetic latitude of λ = 9 °N at sea level. The investigations have been performed by means of a magnetic spectrograph using the spark chamber technique for track location. The measured spectrum in the low-energy region is about 20% smaller than the spectra at high geomagnetic latitudes. The integral intensity for particles which penetrate more than 15 cm of lead is 7.25 × 10−3 cm−2 s−1 sr−1. The theoretical spectrum after Olbert is in agreement with our results.

INTERPLANETARY AND SOLAR PLASMA PARAMETERS OF THE 14 JULY 2000 GROUND LEVEL ENHANCEMENT

2003 ◽  
Vol 12 (02) ◽  
pp. 337-344 ◽  
Author(s):  
S. S. AL-THOYAIB
Keyword(s):  
Rapid Change ◽  
Cosmic Ray ◽  
Ground Level ◽  
Low Energy ◽  
Neutron Monitors ◽  
Ground Level Enhancement ◽  
Plasma Parameters ◽  
Cosmic Ray Intensity ◽  
The Difference ◽  
Galactic Cosmic Ray

The ground level enhancement (GLE) of 14 July 2000 observed in the cosmic ray intensity has been examined. The event was recorded only by neutron monitors. It has a complex intensity-time structure. The northern hemisphere stations (Thule, Goose Bay, and Oulu) recorded abrupt increases earlier by 10 minutes than those in the southern hemisphere. Due to the difference in sensitivity at rigidity less than ~3 GV, the considered detectors recorded different increases in count rates relative to galactic cosmic ray background. This paper presents the study of GLE associated with the X5.7 solar flare. The rapid change of arriving particles were anisotropic during the onset of the event; it become isotropic during the declining phase of the event, where only low energy protons remained. In addition, the observations of energetic solar particles and interplanetary parameters have been examined.

scholarly journals Cosmic-Ray Transport in Simulations of Star-forming Galactic Disks

2021 ◽  
Vol 922 (1) ◽  
pp. 11
Author(s):  
Lucia Armillotta ◽  
Eve C. Ostriker ◽  
Yan-Fei Jiang
Keyword(s):  
Cosmic Rays ◽  
Galactic Disk ◽  
Effective Diffusion ◽  
Cosmic Ray ◽  
High Energy ◽  
Low Energy ◽  
Scattering Coefficient ◽  
Alfven Wave ◽  
High Energy Cosmic Rays ◽  
Scattering Rate

Abstract Cosmic-ray transport on galactic scales depends on the detailed properties of the magnetized, multiphase interstellar medium (ISM). In this work, we postprocess a high-resolution TIGRESS magnetohydrodynamic simulation modeling a local galactic disk patch with a two-moment fluid algorithm for cosmic-ray transport. We consider a variety of prescriptions for the cosmic rays, from a simple, purely diffusive formalism with constant scattering coefficient, to a physically motivated model in which the scattering coefficient is set by the critical balance between streaming-driven Alfvén wave excitation and damping mediated by local gas properties. We separately focus on cosmic rays with kinetic energies of ∼1 GeV (high-energy) and ∼30 MeV (low energy), respectively important for ISM dynamics and chemistry. We find that simultaneously accounting for advection, streaming, and diffusion of cosmic rays is crucial for properly modeling their transport. Advection dominates in the high-velocity, low-density hot phase, while diffusion and streaming are more important in higher-density, cooler phases. Our physically motivated model shows that there is no single diffusivity for cosmic-ray transport: the scattering coefficient varies by four or more orders of magnitude, maximal at density n H ∼ 0.01 cm−3. The ion-neutral damping of Alfvén waves results in strong diffusion and nearly uniform cosmic-ray pressure within most of the mass of the ISM. However, cosmic rays are trapped near the disk midplane by the higher scattering rate in the surrounding lower-density, higher-ionization gas. The transport of high-energy cosmic rays differs from that of low-energy cosmic rays, with less effective diffusion and greater energy losses for the latter.

Sign in / Sign up

Export Citation Format

Share Document