IJAA  Vol.3 No.2 A , June 2013
Calculation of 10Be & 14C Production Rates in the Solar Atmosphere: Implications for Solar Flare Spectral Index
Author(s) Glynn E. Bricker
ABSTRACT

Production rates for the short-lived radionuclides 10Be (T1/2=1.36Myr) and14C(T1/2=5730 yr) in the solar atmosphere were calculated. As both radionuclides are produced through spallation reaction of solar energetic particles (SEP) with oxygen as the primary target, the prevalence of each radionuclide is linked. For the calculations, we assumed power law distribution for SEP with spectral index, r, ranging from 2.5 to 4. We find the 10Be and14Cflux rate at the surface of the Sun to range from 0.007 cm﹣2.s﹣1 to 2.55 cm﹣2.s﹣1 for 10Be, and from 0.13 cm﹣2.s﹣1 to 24.13 cm﹣2.s﹣1 for14C. These radio-nuclides are then entrained in the solar wind. From these flux rate calculations and comparison with experimentally measured flux rates ,we find the most likely time averaged solar flare spectral index to be r = ~3.3.


Cite this paper
G. Bricker, "Calculation of 10Be & 14C Production Rates in the Solar Atmosphere: Implications for Solar Flare Spectral Index," International Journal of Astronomy and Astrophysics, Vol. 3 No. 2, 2013, pp. 17-20. doi: 10.4236/ijaa.2013.32A003.
References
[1]   M. Neugebauer and C. W. Snyder, “The Mission of Mariner II: Preliminary Observations, Solar Plasma Experiment,” Science, Vol. 138, No. 3545, 1962, pp. 1095-1097.

[2]   K. Nishiizumi and M. W. Caffee, “Beryllium-10 from the Sun,” Science, Vol. 294, No. 5541, 2001, pp. 352-354. doi:10.1126/science.1062545

[3]   A. J. T Jull, D. Lal and D. J. Donahue, “Evidence for a Non-Cosmogenic Implanted 14C Component in Lunar Samples,” Earth & Planetary Science Letters, Vol. 136, No. 3-4, 1995, pp. 693-702. doi:10.1016/0012-821X(95)00163-7

[4]   A. J. T. Jull, D. Lal, L. R. McHargue, G. S. Burr and D. J. Donahue, “Cosmogenic and Implanted Radionuclides Studied by Selective Etching of Lunar Soils,” Nuclear Instruments & Methods in Physics Research Section B, Vol. 172, No. 1-4, 2000, pp. 867-872. doi:10.1016/S0168-583X(00)00232-9

[5]   R. O. Pepin, R. H. Becker and D. J. Schlutter, “Irradiation Records in Regolith Materials I: Isotopic Compositions of Solar Wind Neon and Argon in Single Lunar Mineral Grains,” Geochimica et Cosmochimica Acta, Vol. 63, No. 13-14, 1983, pp. 2145-2162. doi:10.1016/S0016-7037(99)00002-2

[6]   I. Lange and S. E. Forbush, “Note on the Effect on Cosmic-Ray Intensity of the Magnetic Storm of March 1, 1942,” Terrestrial Magnetism and Atmospheric Electricity, Vol. 47, No. 2, 1942, pp. 185-186. doi:10.1029/TE047i002p00185

[7]   R. C. Reedy and K. Marti, “Solar-Cosmic-Ray Fluxes During the Last 10 Million Years,” In: C. P. Sonnet, M. S. Giampapa and M. S. Mathews, Eds., The Sun in Time, University of Arizona Press, Tucson, 1991, pp. 260-287.

[8]   X. M. Hua, R. Ramaty and R. E. Lingenfelter, “Deexcitation Gamma-Ray Line Emission from Solar Flare Magnetic Loops,” The Astrophysical Journal, Vol. 341, No. 1, 1989, pp. 516-532. doi:10.1086/167513

[9]   R. C. Reedy, “Fossil Record in the Earth Moon and Meteorites,” In: R. O. Pepin, et al. Eds., The Ancient Sun, Pergamon, Oxford, 1980, pp. 365-886.

[10]   R. C. Reedy, “Constraints on Solar System Events from Comparisons of Recent Events and Million Year Averages,” In: K. S. BalaSunramaniam, S. L. Klein and R. N. Smartt, Eds., ASP Conference Series Solar Drivers of the Interpalnetary and Terrestrial Disturbances, ASP, San Francisco, 1996, pp. 429-436.

[11]   K. Lodders, “Solar System Abundances and Condensation Temperatures of the Elements,” The Astrophysical Journal, Vol. 591, No. 2, 2003, pp. 1220-1247. doi:10.1086/375492

[12]   P. Rabitaille, “The Solar Photosphere: Evidence for Condensed Matter,” Progress in Physics, Vol. 2, 2006, pp. 17-20.

[13]   M. Gounelle, F. H. Shu, H. Shang, A. E. Glassgold, K. E. Rehm and T. Lee, “The Irradiation Origin of Beryllium Radioisotopes and Other Short-lived Radionuclides,” The Astrophysical Journal, Vol. 640, No. 2, 2006, pp. 1163-1170. doi:10.1086/500309

[14]   J. M. Sisterson, et al., “Measurement of Proton Production Cross Sections of 10Be and 26Al from Elements Found in Lunar Rocks,” Nuclear Instruments & Methods in Physics Research Section B, Vol. 123, No. 1-4, 1997, pp. 324-329. doi:10.1016/S0168-583X(96)00409-0

[15]   A. S. Iljinov, et al., “Production of Radionuclides at Intermediate Energies,” In: H. Schopper, Ed., LandholtBornstein. Springer-Verlag, Berlin, Heidelberg, New York, 1994.

[16]   H. J. Lange, et al., “Production of Residual Nuclei by α-induced Reactions on C, N, O, Mg, Al and Si up to 170 MeV,” Applied Radiation and Isotopes, Vol. 46, No. 2, 1995, pp. 93-112. doi:10.1016/0969-8043(94)00124-I

[17]   J. M. Sisterson, et al., “Revised Solar Cosmic Ray Fluxes Estimated Using Measured Depth Profiles of 14C in Lunar Rocks; The Importance of Good 14C Cross Section Determinations,” Lunar & Planetary Science, Vol. 27, 1196, pp. 1209-1210.

[18]   K. Nishiizumi, et al., “10Be Profiles in Lunar Surface Rock 68815,” Proceeding of 11th Lunar and Planetary Science conference, Houston, 16 March 1987, pp. 79-85.

 
 
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