Simulation of the interactions of galactic cosmic ray protons by irradiation of a thick stony target with 1.6 GeV protons

Michel, R.; Lüpke, Matthias; Herpers, U.; Rösel, R.; Filges, D.; Dragovitsch, P.; Wölfli, W.; Dittrich, B.; Hofmann, Hans

doi:10.1007/bf02046779

Cited by 18 publications

(3 citation statements)

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“…Ammon et al 2008a), is an improved version of the one used earlier by Leya et al (2000aLeya et al ( , 2000bLeya et al ( , 2001a. Briefly, the neutron excitation functions are extracted from production rates obtained in five thick target simulation experiments (e.g., Michel et al 1985Michel et al , 1989Michel et al , 1993Lüpke 1993;Leya et al 2000b). We start with a priori neutron excitation functions as guess functions and derive the a posteriori neutron cross sections, which are then used for modeling using an energy dependent least squares adjustment procedure.…”

Section: Cross Sectionsmentioning

confidence: 99%

Cosmogenic nuclides in stony meteorites revisited

Leya

Masarik²

2009

Meteorit & Planetary Scien

189

508

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Leya et al. (2000a), folds together particle spectra and cross sections for the relevant nuclear reactions, but has been significantly improved due to major improvements in the neutron cross section database and better Monte Carlo modeling of the primary and the secondary particle spectra. The data presented here replace (and extend) the results of our earlier model predictions. Here we give for ordinary and carbonaceous chondrites elemental production rates for the cosmogenic radionuclides 10 Be, 14 Ar, and 38 Ar. Using the new data and expressing size and depth scales to the unit [g/cm 2 ], we are able to demonstrate that the matrix effect for both chondrite types is negligible for all target product combinations, except for those which are dominated by thermal or very low energy neutron reactions. Based on the new model predictions, we present a variety of elemental and isotopic production rate ratios allowing for a reliable determination of preatmospheric sizes, shielding depths, cosmic-ray exposure ages, and diffusive losses.

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Section: Cross Sectionsmentioning

confidence: 99%

Cosmogenic nuclides in stony meteorites revisited

Leya

Masarik²

2009

Meteorit & Planetary Scien

189

508

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“…Provided the cross sections of the proton-induced production are well known, the neutron excitation functions can be extracted from the thick-target production rates by unfolding techniques starting from theoretical guess functions. From production rates measured in artificial stony and iron meteoroids irradiated isotropically with 600 MeV at CERN [86,87] and with 1.6 GeV protons at LNS/ Saclay [71,88] a consistent set of neutron excitation functions for more than 500 target/product combinations derived [73]. These neutron cross sections provided the basis for physical model calculations describing all aspects of cosmogenic nuclide production in extraterrestrial matter and for nuclide production at medium energies in general [64,[72][73][74][75].…”

Section: Cosmogenic Nuclides In Extraterrestrial Mattermentioning

confidence: 99%

“…Because of the complexity of the medium-energy processes of GCR interactions, terrestrial simulation experiments are of importance in which the complex occurrences of GCR interactions with dense matter can be studied under controlled conditions and by which GCR models can be bench-marked. Such experiments were performed and the GCR exposure of stony and iron meteoroids was simulated by isotropic irradiations of artificial meteoroids with 600 MeV and 1.6 GeV protons [71,83,[86][87][88], The measurement of longlived radionuclides in all these experiments was possible only because of the availability of accelerator mass spectrometry. On the basis of these simulation experiments, the model calculations were verified to describe the depth-and size-dependent production of residual nuclei by medium-energy protons within 10% for production rates and within 2-3% for production rate ratios.…”

Section: The Long-term Spectra Of Scr and Gcr Particlesmentioning

confidence: 99%

Long-Lived Radionuclides as Tracers in Terrestrial and Extraterrestrial Matter

Michel

1999

Radiochimica Acta

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Environmental radioactivity / Cosmogenic radionuclides / Long-lived radionuclides / Accelerator mass spectrometry / Natural and mass-made tracers SummaryRadionuclides in nature offer unique opportunities for radioactive dating and tracing of natural and man-made processes. Naturally occurring radionuclides with half-lives between a few days and IO 12 a have found widespread applications some of which are surveyed here. After a short glance on radionuclide production in stellar nucleosynthesis and on extinct radionuclides in the early solar system, applications are discussed of the long-lived (5 ka < T 1/2 < 16 Ma) radionuclides 10 Be, 14 C, 26 Al, ,6 C1, 41 Ca, "Mn, 59 Ni, and 129 I in cosmochemistry and -physics and in the earth and environmental sciences. These nuclides occur in nature as cosmogenic and partially as radiogenic nuclides and some of them were brought into the terrestrial environment by man. Methods to analyze them at their natural levels are reviewed. Applications are highlighted which cover the cosmic ray record in extraterrestrial matter and in various terrestrial compartments and archives. Emphasis is put on the distinction of mechanisms affecting constancy or variability of the observed natural radionuclide abundances. Finally, the longterm human impact on the radiation environment and the relevance of long-lived radionuclides for the human radiation exposure is discussed. Radionuclides in natureRadioactive nuclides with half-lives between 7.2 · IO 24 a ( I28 Te) and 17 ns ( 212m Po) occur naturally in the solar system and in our terrestrial environment as primordial, radiogenic, nucleogenic or cosmogenic nuclides. More than 20 primordial radionuclides, among them <°K, 87 Rb, 232 Th, 235 U, and 238 U, have sufficiently long half-lives to survive the time since the closing of the solar system. Radionuclides with shorter half-lives are continuously produced. Radiogenic nuclides originate from radioactive decay or spontaneous fission of primordial radionuclides. Nucleogenic ones are produced by nuclear reactions induced by α-particles and neutrons from radioactive decay and spontaneous fission, respectively. Finally, cosmogenic nuclides are the products of interactions of primary and secondary solar and galactic cosmic ray particles with matter. *

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2009

Handbook of Spallation Research

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Simulation of the interactions of galactic cosmic ray protons by irradiation of a thick stony target with 1.6 GeV protons

Cited by 18 publications

References 18 publications

Cosmogenic nuclides in stony meteorites revisited

Cosmogenic nuclides in stony meteorites revisited

Long-Lived Radionuclides as Tracers in Terrestrial and Extraterrestrial Matter

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