1,721,079 research outputs found
Production Rates for Cosmogenic Nuclides in Meteorites
No full textProduction Rates for Cosmogenic Nuclides in Meteorite
Cross Sections Relevant for Cosmochemical Applications
No full textCross sections for proton-, neutron-, and alpha-induced reactions relevant for geo- and cosmochemical applications. The first column gives the energy in MeV, the second column gives the uncertainties of the energy (also in MeV), the third column gives the cross section in (mb) and the fourth column gives the uncertainty of the cross section (also in mb). The last column gives a label, which bis either for the computer code use for modelling (INCL, Talys, ..) or is an acronym for the reference
10Be Production Rates in Meteorites
No full textModelled 10Be production rates in various types of meteorite
14C-Production Rates in Meteorites
No full textModeled production rates for 14C in various types of meteorite
Particle Spectra for L-chondrites R = 45 cm variable solar modulation function M
No full textDifferential particle spectra for protons, neutrons, and alpha-particles for L-chondrites with a pre-atmospheric radius of 45 cm and variable solar modulation potential (between 100 MV - 1000 MV in steps of 50 MV). The particle spectra are in the unit [cm2 s MeV]^-1
Cosmogenic effects on LI-L-7/LI-L-6, B-10/B-11, and W-182/W-184 in carbonaceous chondrites
No full textThe Influence of Mineral Inclusions on the Production Rates of Cosmogenic Nuclides in Grant (IIIAB) and Carbo (IID)
No full textCosmogenic production rates and recoil loss effects in micrometeorites and interplanetary dust particles
No full textWe present a purely physical model to determine cosmogenic production rates for noble gases and radionuclides in micrometeorites (MMs) and interplanetary dust particles (IDPs) by solar cosmic-rays (SCR) and galactic cosmic-rays (GCR) fully considering recoil loss effects. Our model is based on various nuclear model codes to calculate recoil cross sections, recoil ranges, and finally the percentages of the cosmogenic nuclides that are lost as a function of grain size, chemical composition of the grain, and the spectral distribution of the projectiles. The main advantage of our new model compared with earlier approaches is that we consider the entire SCR particle spectrum up to 240 MeV and not only single energy points. Recoil losses for GCR-produced nuclides are assumed to be equal to recoil losses for SCR-produced nuclides. Combining the model predictions with Poynting-Robertson orbital lifetimes, we calculate cosmic-ray exposure ages for recently studied MMs, cosmic spherules, and IDPs. The ages for MMs and the cosmic-spherule are in the range <2.2–233 Ma, which corresponds, according to the Poynting-Robertson drag, to orbital distances in the range 4.0–34 AU. For two IDPs, we determine exposure ages of longer than 900 Ma, which corresponds to orbital distances larger than 150 AU. The orbital distance in the range 4–6 AU for one MM and the cosmic spherule indicate an origin either in the asteroid belt or release from comets coming either from the Kuiper Belt or the Oort Cloud. Three of the studied MMs have orbital distances in the range 23–34 AU, clearly indicating a cometary origin, either from short-period comets from the Kuiper Belt or from the Oort Cloud. The two IDPs have orbital distances of more than 150 AU, indicating an origin from Oort Cloud comets
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