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  • 1 Institut für Kernchemie der Universität zu Köln Zülpicher Str. 47 D-5000 Köln 1 (FRG)
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Abstract  

In order to interpret cosmogenic radionuclides in extraterrestrial matter one has to differentiate between p- and α-induced reactions with solar (SCR) and with galactic (GCR) cosmic rays. Our earlier studies have shown that for a satisfactory description of GCR-interactions with dense matter rather few but characteristic high energy cross sections are required. In contrast, for the low and medium energy SCR-production a detailed knowledge of the respective nuclear reactions is needed. In the present study, excitation functions are presented for 39 p-induced reactions on Ni, Fe, Mn, Cr and Ti, which contribute to SCR-produced radionuclides (44≤A≤59) at energies up to 200 MeV. The excitation functions are based mainly on our own cross section measurements, partly on hybrid model predictions and to a lesser extent on experimental data from other authors. Based on these excitation functions, depth profiles for the proton induced SCR-production of46Sc,44Ti,48V,51Cr,52Mn,53Mn,54Mn,55Fe,56Co,57Co,58Co,60Co and59Ni from the 5 major targets mentioned before in extraterrestrial matter are calculated, assuming normal lunar surface conditions. Typical rigidities were adopted for the solar proton fluxes, ranging from 50 to 150 MV, which cover the rigidity values commonly observed in solar flares. In order to derive depth dependent p-fluxes from calculations of the energy loss of incoming particles, rather large differences in the respective chemical compositions had to be considered. The theoretical profiles are compared with experimental data from lunar samples, and several cosmochemical applications are discussed. They range from the study of single solar flare events by short-lived radioisotopes to the investigation of supposed long-term variations of the solar flare activity on a large times-cale of millions of years. The latter is possible by comparing the production rates of very long-lived nuclides (as for example53Mn with T=3,8·106 y) with that of short- or medium-lived nuclides. In this respect, the particular importance of44Ti (T-47.3 y) for measuring today's mean solar flare activity is pointed out. In general, the depth dependent production rates established in this work enable one to estimate the SCR-contributions to cosmogenic radionuclides from the respective target elements, thus providing a basis for a better understanding of the solar cosmic ray interaction with extraterrestrial matter.

Manuscript Submission: HERE

  • Impact Factor (2019): 1.137
  • Scimago Journal Rank (2019): 0.360
  • SJR Hirsch-Index (2019): 65
  • SJR Quartile Score (2019): Q3 Analytical Chemistry
  • SJR Quartile Score (2019): Q3 Health, Toxicology and Mutagenesis
  • SJR Quartile Score (2019): Q2 Nuclear Energy and Engineering
  • SJR Quartile Score (2019): Q3 Pollution
  • SJR Quartile Score (2019): Q3 Public Health, Environmental and Occupational Health
  • SJR Quartile Score (2019): Q3 Radiology, Nuclear Medicine and Imaging
  • SJR Quartile Score (2019): Q3 Spectroscopy
  • Impact Factor (2018): 1.186
  • Scimago Journal Rank (2018): 0.408
  • SJR Hirsch-Index (2018): 60
  • SJR Quartile Score (2018): Q2 Nuclear Energy and Engineering
  • SJR Quartile Score (2018): Q2 Pollution

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Journal of Radionalytical and Nuclear Chemistry
Language English
Size A4
Year of
Foundation
1968
Volumes
per Year
4
Issues
per Year
12
Founder Akadémiai Kiadó
Founder's
Address
H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
Publisher Akadémiai Kiadó
Springer Nature Switzerland AG
Publisher's
Address
H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
CH-6330 Cham, Switzerland Gewerbestrasse 11.
Responsible
Publisher
Chief Executive Officer, Akadémiai Kiadó
ISSN 0236-5731 (Print)
ISSN 1588-2780 (Online)