The Role of Nuclei-Nuclei Interactions in the Production of Gamma-ray Lines in Solar Flares

Solar Cosmic Rays

“…In contrast to this, the calculations for two versions of abundances of these elements in the solar atmosphere ("a" and "b" correspond to Aller (1961) and Cameron (1973), respectively), give some evidence of that the ratios of fluxes of gamma rays from 12 C and from other nuclei in this experiment should be as those given in (Table 6.5), if we take into account only the processes of pk-and αk-interactions (for more details see Kuzhevskij et al 2005b).…”

“…Dramatic extensions of experimental possibilities (spacecraft RHESSI, CORONAS-F, INTEGRAL and others) in solar gamma-ray astronomy call for more detailed consideration of a set of physical problems related to the production of gamma-radiation in the processes of interactions of energetic (accelerated) heavy and middle nuclei with that of elements of the solar atmosphere (so-called heavy-heavy or ij-interactions). According to some estimates (Kuzhevskij et al 2005b), a contribution of these interactions between accelerated and background nuclei in the gamma-ray production in the solar atmosphere may be more important that it was thought earlier. This conclusion is confirmed by a comparison of theoretical estimates (Kuzhevskij et al 2005b) and observations during the RHESSI flare of 23 July 2002 .…”

“…According to some estimates (Kuzhevskij et al 2005b), a contribution of these interactions between accelerated and background nuclei in the gamma-ray production in the solar atmosphere may be more important that it was thought earlier. This conclusion is confirmed by a comparison of theoretical estimates (Kuzhevskij et al 2005b) and observations during the RHESSI flare of 23 July 2002 .…”

Using Gamma‐Ray and Neutron Emission to Determine Solar Flare Accelerated Particle Spectra and Composition and the Conditions within the Flare Magnetic Loop

“…Accelerated -particles and heavier ions interacting with ambient H and He produce ''broad'' lines (fractional FWHM $20%) due to the relatively high recoil velocity of the nucleus. Recently, Kuzhevskij et al (2005a) considered deexcitation line yields from heavy-heavy nucleus interactions, but we have found that for the narrow 1.634 MeV 20 Ne and 1.369 MeV 24 Mg lines produced by interactions of 12 C and 16 O, the yields are negligible due to both the lower abundances of both species and the higher energy loss of heavy particles. Accelerated ion interactions also create radioactive nuclei, which produce delayed -ray lines that can be observed when the prompt emission is negligible (Tatischeff et al 2006).…”

The investigation of powerful solar flares characteristics by analysis of excited states of 12C and various neutrons capture lines

“…(4) Secondary processes by radioactive nuclei produced in interactions of accelerated a-particles and heavier ions with ambient H and He (Lingenfelter and Ramaty, 1967;Ramaty et al, 1979;Murphy et al, 2007;Chupp et al, 1973) -broad c-lines with fractional FWHM around 20% (as the recoil velocity of a nucleus is relatively high). (5) Secondary processes by radioactive nuclei produced in heavy-heavy interactions -relatively narrow clines (for example, 1.634 MeV 20 Ne, 1.369 MeV 24 Mg and 0.937 MeV 18 F (Murphy et al, 2007;Kuzhevskij et al, 2005;Kozlovsky et al, 2004) -broad c-lines with fractional FWHM $ 20% (as the recoil velocity of a nucleus is relatively high). (6) Neutron capture lines -at 2.223 MeV and probably 20.58 MeV (Kuzhevskii, 1982;Alfimenkov et al, 1979;Zurmü hle et al, 1963;Bystritsky et al, 2006;Komar et al, 1993;Wolfs et al, 1989).…”