Cross sections of electron excitation of atomic nuclei in plasma

Thorium silicate compound as a solid-state target for production of isomeric thorium-229 nuclei by electron beam irradiation

“…When the electron energy exceeds the energy of the nuclear transition by 1.5-2 times, the actual cross-section of M1 excitation can exceed the Born approximation by one-two orders of magnitude. 20 Therefore, it is expected that the output of isomeric nuclei in this process will be larger than the above estimates.…”

“…This expression gives a good estimate when using the result of the Born approximation 20 and the cross-section of excitation of the isomeric state is weakly, mainly logarithmically dependent on the energy.…”

Expected yields of $^{181}$Ta (e,e') $^{181}$Ta$^*$ in the multi-keV range with a plasma-cathode electron beam

“…The high number of electrons in plasmas can lead to significant nuclear excitation rates, even though the expected cross sections are small, often well under 10 −30 cm 2 . The process of electron inelastic scattering has been experimentally and theoretically studied in the MeV energy range [11][12][13][14] but in the keV range of interest as in astrophysical plasmas [4] only a few models have been developed to calculate the expected cross sections [15][16][17][18]. The main theoretical problem lies in the determination of the radial matrix element that describes the incident electron.…”

“…The classical description of the inelastic collision is highly questionable as the energy loss of the electron during the nuclear transition is not small compared to the incident energy, so the effect of the nuclear excitation on the particle motion cannot be neglected. More complete quantum-mechanical treatments of inelastic electron scattering have been performed by several authors [16][17][18] in the multi-keV energy range. In these approaches, the interaction was treated as a static Coulomb field [16,17] or as a result of exchange by virtual photons between the electrons and the nucleus [18].…”

“…More complete quantum-mechanical treatments of inelastic electron scattering have been performed by several authors [16][17][18] in the multi-keV energy range. In these approaches, the interaction was treated as a static Coulomb field [16,17] or as a result of exchange by virtual photons between the electrons and the nucleus [18]. The excitation cross sections can be expressed as sums of terms referring to the different orbital momentum l i and l f of (Letokhov 1994: [15], Tkalya 2012: [18]).…”