Heavy ion testing at the galactic cosmic ray energy peak (original) (raw)
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Impact of high-energy cosmic-ray protons and ions on the elements of spacecraft on-board devices
Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques, 2012
The radiation environment in space is reviewed in short as an impact factor affecting onboard spacecraft electronics. The mass and energy distributions of the heavy component of space radiation and the contribution of galactic cosmic rays to the general flux are analyzed during a quiet period in solar activity. The nature of the limitations in the concept of linear energy transfer, including the effects of electronic semicon ductor component crystallinity, is discussed. Protective measures against upsets in onboard electronics, caused by cosmic ray ions, are considered.
Shielding experiments with high-energy heavy ions for spaceflight applications
New Journal of Physics, 2008
Mitigation of radiation exposures received by astronauts on deepspace missions must be considered in the design of future spacecraft. The galactic cosmic rays (GCR) include high-energy heavy ions, many of which have ranges that exceed the depth of shielding that can be launched in realistic scenarios. Some of these ions are highly ionizing (producing a high dose per particle) and for some biological endpoints are more damaging per unit dose than sparsely ionizing radiation. The principal physical mechanism by which the dose and dose equivalent delivered by these particles can be reduced is nuclear fragmentation, the result of inelastic collisions between nuclei in the hull of the spacecraft and/or other materials. These interactions break the incident ions into lighter, less ionizing and less biologically effective particles. We have previously reported the tests of shielding effectiveness using many materials in a 1 GeV nucleon −1 56 Fe beam, and also reported results using a single polyethylene (CH 2) target in a variety of beam ions and energies up to 1 GeV nucleon −1. An important, but tentative, conclusion of those studies was that the average behavior of heavy ions in the GCR would be better simulated by heavy beams at energies above 1 GeV nucleon −1. Following up on that work, we report new results using beams of 12 C, 28 Si and 56 Fe, each at three energies, 3, 5 and 10 GeV nucleon −1 , on carbon, polyethylene, aluminium and iron targets.
Properties of Low Energy Ions Observed in the Sky lab Cosmic Ray Experiment
1977
Low energy cosmic ray nuclei in space were detected using a stack of Lexan polycarbonate exposed in free space outside the Skylab orbital station for 73 days (from 22 Nov. 1973 to 3 Feb. 1974, a solar "quiet" period). Since at the time of exposure the sun was typically quiet, it has become possible to study the low energy particles during solar minimum, that is free from contamination of solar particles. This is also the longest exposure in space for a retrievable detector with a thin shielding of only about 25 mgfcm2 of aluminium so that low intensity low energy particles could be recorded in appreciable numbers. Energy spectra and relative abundance of carbon to nickel nuclei have been derived from the measurements of etch tracks in plastic sheets. The following important information emerges out of the work: (i) A high flux of oxygen group (C, N, 0) nuclei in the energy interval 10-25 MeV{amu having unusual composition (with oxygen much more enhanced relative to carbon) ...
Skylab measurements of low energy cosmic rays
Space Science Reviews, 1980
In this review the present state of our knowledge on the properties of heavy ions in low energy cosmic rays measured in the Skylab mission and in other spacecrafts is summarised and the possible mechanisms of their origin are discussed. A brief review of the general features of the galactic and solar cosmic rays is given in order to understand the special features of the low energy heavy ions of cosmic rays. The results of the cosmic ray experiment in the Skylab show that in the low energy interval of 8-30 MeV/N, the abundances of oxygen, nitrogen, and neon ions, relative to carbon are enhanced by a factor of 5 to 2 as compared to high energy cosmic rays; while Mg, Si, S, and A are depleted. In 50-150 MeV/N energy interval the abundance of nuclei of Ca-Cr relative to iron-group (Z = 25-28) is found to be highly enhanced I as compared to high energy cosmic rays. Furthermore the observations of the energy spectra of O, N, andNe ions and their fairly large fluences in the energy interval of 8-30 MeV/N below the geomagnetic cut off energy of 50 MeV/N for fully stripped nuclei at the Skylab orbit indicate that these heavy ions are probably in partly ionised states. Thus, it is found that the Skylab results represent a new type of heavy ion population of low energy cosmic rays below 50 MeV/N, in the near Earth space and their properties are distinctly different from those of high energy cosmic rays and are similar to those of the anomalous component in the interplanetary space. The available data from the Skylab can be understood at present on the hypothesis that low energy interplanetary cosmic ray ions of oxygen etc. occur in partly ionised state such as 0 +1, O +2, etc. and these reach the inner magnetosphere at high latitudes where stripping process occurs near mirror points and this leads to temporarily trapped ions such as O +3, 0 +4, etc. It is noted that the origin of these low energy heavy cosmic ray ions in the magnetosphere and in interplanetary space is not yet fully understood and new type of sources or processes are responsible for their origin and these need further studies.
Penetrating component in cosmic rays
arXiv: High Energy Astrophysical Phenomena, 2019
We present a study of the high energy spectra of hadrons in cores of extensive air showers. These data were obtained for the first time in the hybrid {\it HADRON} experiment (Tien-Shan) by means of a large X-ray emulsion chamber combined with the shower array. In the local energy interval 3--100 PeV an increase in the energy of hadrons was found, which means the appearance of a penetrating component. This component in our experiment was observed in the atmosphere that indicates the presence of a penetrating strongly interacting component in primary cosmic rays. Along with that, it is worth emphasising that the region where this component is observed coincides with the region of the so-called knee in the spectrum of cosmic rays. On this basis, a new hypothesis of knee formation can be put forward.
Measurement of the energy spectra of cosmic ray electron component and protons at ground level
Journal of Geophysical Research, 1995
Using a superconducting magnet spectrometer, we have measured the energy spectra of electrons, positrons, and protons at ground level at an atmospheric depth of 945 g/cm 2. The differential energy spectrum of the electron component has been determined in the momentum interval between 0.1 and 2.0 GeV/c. This spectrum can be described by two power laws, one below 600 MeV with a spectral index of -1.8 + 0.1 and the other above this energy with an index of -2.9 _+ 0.2. The absolute flux values measured here are not in agreement with the earlier results. The fraction of positrons varies from a value of 0.45 at 200 MeV to about 0.5 above 1 GeV, which is consistent with the theoretical expectation. The momentum dependence of the e/• ratio in the region between 0.25 and 2.0 GeV/c is proportional to p-•.2, and it appears that the soft component of the ionizing radiation might dominate at ground level at kinetic energies below about 70 MeV. The proton energy spectrum has been determined as a power law in kinetic energy between 2.9 and 19.1 GeV with a spectral index of -2.66 _+ 0.26. The p/l• ratio obtained from this experiment seems to have a steeper momentum dependence than from previous experiments.
IONS (ANURADHA): Ionization states of low energy cosmic rays
1987
IONS (ANURADHA), the experimental payload designed specifically to determine the ionization states, flux, composition, energy spectra and arrival directions of low energy (10 to 100 MeV/amu) anomalous cosmic ray ions of helium to iron in near-Earth space, had a highly successful flight and operation Spacelab-3 mission. The experiment combines the accuracy of a highly sensitive CR-39 nuclear track detector with
The Anuradha cosmic ray experiment in Spacelab-3, flown in the orbit at 350 km with an inclination of 57° for about six days, was used to measure the low energy galactic cosmic ray (GCR) heavy ions using a specially designed CR-39 detector module incorporating the arrival time information of the particles. The abundances of sub-iron (Sc-Cr) and iron particles in the low energy interval of 30-300 MeV/N were determined from the measurements made in four different depths of the CR-39 detector module of 150 layers. From these studies we obtained sub-iron (Sc-Cr) to iron abundance ratios of 0·8 to 1·2 in 30-300 MeV/N energy range. It is found that these ratios are enhanced by a factor of two as compared to interplanetary ratios of about 0·5. It is shown that the enhancement of the ratio inside the earth's magnetosphere is probably due to the degree of ionization of low energy Sc to Cr and Fe ions in the galactic cosmic rays and to the rigidity filtering effects of the geomagnetic field. Further studies are needed to understand fully the phenomena and their implications.