Electron-Excitation—Gamma-Decay Reactions in Heavy Nuclei

Abstract

The feasibility of using the reactions ${e+N({\ensuremath{\epsilon}}_{i},{J}_{i})\ensuremath{\rightarrow}{e}^{\ensuremath{'}}+,N({\ensuremath{\epsilon}}_{f},{J}_{f})}{\ensuremath{\searrow}N({\ensuremath{\epsilon}}_{\mathrm{ff}},{J}_{\mathrm{ff}})+\ensuremath{\gamma}}$ to investigate low-lying states of heavy nuclei is discussed. By detecting the decay photon, the problem of poor energy resolution for high-energy electrons can be circumvented. The formalism for the ${e}^{\ensuremath{'}}\ensuremath{-}\ensuremath{\gamma}$ coincidence cross section is given. The Coulomb distortion of the electron wave functions, which is important for heavy nuclei, is taken into account. Results for the ${e}^{\ensuremath{'}}\ensuremath{-}\ensuremath{\gamma}$ coincidence cross section and the $\ensuremath{\gamma}$-detection cross section for several nuclei are given. The $e\ensuremath{-}\ensuremath{\gamma}$ coincidence cross section appears to be feasible when superconducting accelerators became operational. The $\ensuremath{\gamma}$-detection cross section offers a method for investigating low-lying states with present-day accelerators.