Journal: Journal of Geophysical Research: Space Physics
Title: Propagation of Solar Neutrons through the Atmosphere of the Earth
General Information: Published 1 April 1994, Volume 99, Issue A4, Pages 6651-6665
Author(s): S. Shibata
Abstract: The propagation of solar neutrons through the atmosphere of the Earth has been calculated by a Monte Carlo method using a nuclear interaction model which can reproduce the existing data obtained by accelerator experiments. With this calculation, it has been found that the elastic scattering process plays an important role in the propagation of solar neutrons in the atmosphere at an incident energy below ∼ 200 MeV. By applying this calculation to the analysis of a solar neutron event observed at Mount Norikura Cosmic Ray Observatory on June 4, 1991, it is possible to interpret the event as γ rays and neutrons having been produced impulsively at the time of the solar flare. The event observed at Jungfraujoch on June 3, 1982 can be explained similarly.
Journal: American Institute of Physics: Conference Proceedings
Title: Neutron Monitor Measurements as a Complement to Space Measurements of Energetic Solar Particle Fluxes
General Information: Published online 10 December 1994
Author(s): H. Debrunner
Abstract: Neutron monitors remain indispensable cosmic ray detectors for primary energies from about 500 MeV to 30 GeV. They respond to variations of the cosmic ray intensity of the near‐Earth scape that are no measured by space experiments. The records of the world wide network of standardized neutron monitors, therefore, complement cosmic ray spacecraft measurements. In this review paper we first describe the design of a neutron monitor and its characteristic parameters as a continuous ground‐based cosmic ray instrument. We then discuss how the data from the world wide network of neutron monitors are evaluated to determine the energetic solar proton fluxes in near‐Earth space during the solar cosmic ray events.
We present, as an example, the solar proton fluxes near Earth during the May 7, 1978 solar cosmic ray event. These fluxes were derived from neutron monitor data and measurements of the cosmic ray telescopes on board IMP‐7 and cover the energy range from 50 MeV up to 10 GeV. Finally, we describe the method of analyzing solar neutron events. As an example, we summarize the observations made during the solar flare on June 3, 1982 by the Gamma‐Ray‐Spectrometer on the Solar Maximum Mission Satellite and the Jung‐fraujoch neutron monitor. These measurements were used to determine the directional solar neutron emissivity spectrum of the June 3, 1982 solar neutron event over the energy range from 100 MeV to about 3 GeV.
Hyperlink: You have to pay for this article, but maybe information from the abstract can be used
Journal: Journal of Geophysical Research
Title: Barometric Coefficients of Multiplicities in Neutron Monitors
General Information: Published 1 December 1968, Volume 73, Space Physics, Pages 7503-7509
Author(s): C. J. Hatton, W. K. Griffiths
Abstract: Using a simple model for cosmic-ray interactions in the atmosphere and the response of neutron monitors to secondary nucleons, the barometric coefficients of various multiplicities have been calculated. The variation of these coefficients with multiplicity, latitude, and altitude is found to be in general agreement with experimental results.
Journal: Canadian Journal of Physics
Title: Multiplicity Measurements on the IGY and NM64 Neutron Monitors
General Information: Received 21 June 1967
Author(s): F. Bachelet, E. Dyring, N. Lucci
Abstract: Preliminary results are given of the analysis of the continuous recordings of the detected multiplicity distribution obtained at the Uppsala IGY monitor and at the Rome supermonitor in the first months of 1967. The relative frequencies and the attenuation coefficients of the individual multiplicities as measured at both monitors are compared. The time changes of the multiplicity distribution on the occasion of substantial primary spectral variations are studied.
Journal: The Institute of Physical and Chemical Research
Title: Latitude Survey of Neutron Multiplicity using a ShipBorne NM-64 Neutron Monitor
General Information: Received 19 June 1967
Author(s): M. Kodama, T. Ohuchi
Abstract: The latitude dependence of the neutron multiplicity effect has been measured using a 3-NM-64 neutron monitor along the route Japan-Australia-Antarctic-South Africa-Ceylon-Japan between December 1966 and April 1967. Throughout the whole voyage, events whose multiplicities were in the range 1 to 6 and more were recorded. A preliminary report of the threshold-rigidity dependence of events of various multiplicities is presented, based on data from the outward voyage. The gradient of the rigidity dependence is found to be steepest for events of multiplicity 2, while that for multiplicity 1 is almost the same as that for multiplicity
3. The mean multiplicity of events recorded by the present shipborne neutron monitor varies linearly from 1.418 to 1.445 in the rigidity interval 0.1-17 GV.
Journal: Journal of Geophysical Research
Title: Response of a Standard IGY Neutron Monitor
General Information: Published 1 March 1966, Volume 71, Issue 5, Pages 1435-1444
Author(s): E. B. Hughes, P. L. Marsden
Abstract: On the basis of experimental results on neutron production by protons and muons, the total counting rate and the detected multiplicity spectrum normally recorded by a standard IGY neutron monitor are analyzed in terms of the components of the cosmic radiation at sea level. It is shown that approximately 93% of the detected neutrons are caused by neutron and proton interactions and that a definite relation exists between the detected multiplicity spectrum and the energy spectrum of nucleons at sea level. It is expected that time variations in the rates of the detected multiplicities will reflect the behavior of the primary energy spectrum of the cosmic radiation at energies up to the order of 200 Gev, and that this will be useful in the study of the various time-dependent phenomena of the cosmic radiation.
Journal: Proceedings of the national Academy of Sciences of the United States of America
Title: Solar Origin of Changes in the Primary Cosmic Radiation
General Information: Published 15 January 1957, Volume 43, Issue 1, Pages 42-56
Author(s): J. A. Simpson
Abstract: Not Applicable, but here is the last paragraph of the article:
In summary, it is likely that further studies of cosmic-ray intensity variations may (a) extend our knowledge of the electrodynamics of the solar system and the nature of geomagnetic storms in particular, (b) place upper limits on the production of cosmic rays at the sun, and (c) enable us to gain further information on the galactic spectrum.