The 6th International Conference on Matter and Radiation at Extremes (ICMRE2023)

150 / 2023-04-14 20:53:21

Electronic excitation processes of the 229Th isomer in laser-generated plasmas

thorium-229,isomer,nuclear excitation,plasma

Fundamental Physics at Extreme Light > QED effect and nuclear physics-I

The ²²⁹Th nucleus has an extremely low-lying isomeric state of energy at approximately 8 eV [1,2]. This unusual isomer is a potential candidate for a “nuclear optical clock” [3]. One of the current research focuses is to find efficient methods to produce the isomer, i.e., exciting the ²²⁹Th nucleus from the ground state to the isomeric state [4,5].



We consider electronic excitation processes for the isomeric excitation. These processes include nuclear excitation by electron transition (NEET), nuclear excitation by electron capture (NEEC), and nuclear excitation by inelastic electron scattering (NEIES). A unified theoretical framework is developed to calculate these processes [6,7]. These processes may also co-exist, such as in a laser-generated plasma [8]. Which process prevails is determined by the plasma condition. Several examples will be given.



[1] L. Kroger and C. Reich, Nucl. Phys. A 259, 29 (1976).

[2] B. Seiferle et al., Nature 573, 243 (2019).

[3] A. Yamaguchi et al., Phys. Rev. Lett. 123, 222501 (2019).

[4] K. Beeks et al., Nat. Rev. Phys. 3, 238 (2021).

[5] W. Wang, J. Zhou, B. Liu, and X. Wang, Phys. Rev. Lett. 127, 052501 (2021).

[6] H. Zhang, W. Wang, and X. Wang, Phys. Rev. C. 106, 044604 (2022).

[7] H. Zhang and X. Wang, submitted.

[8] P. V. Borisyuk et al., arXiv: 1804.00299.