Quantum seminar | 27 November 2024

The idea of laser manipulating the nuclear energy remains always tempting. However, a cool mind tells that the electrical strength of the field produced by the strongest lasers are weaker than that in the nuclear volume by orders of magnitude, even if focused at a spot of a tiny fraction of a square millimeter. At the time being, this idea has intertwined with two others: that the interplay of the Coulomb and nuclear force is able to detect a drift if exists of the fundamental constants in time, and that of nuclear-optical clocks whose high selective sensitivity to the both components present a unique chance not only to confirm the change of the constants, but also help essentially in searches for dark matter and dark energy – unknown substance comprising 95% of the Universe. The idea of making use of the resonance properties of the electron shell, aimed at enhancing of the action of an external electromagnetic field on the nuclei, is under discussion in the paper. The method proposed allows one to realize the optical pumping with a cross-section two orders of magnitude higher than the cross-section that took place in PTB in their milestone experiment on excitation of the 229mTh nuclear isomer by laser.

Main paper/arXiv, related to the seminar, and other references, up to 5:

• J. Tiedau et al. Laser Excitation of the Th-229 Nucleus. Phys. Rev. Lett. 132, 182501 (2024)
• Ф. Ф. Карпешин, М. Б. Тржасковская. Резонансная оптическая накачка изомера 229Th с энергией 8 эВ. ЖЭТФ 165, 145 (2024)
• F. F. Karpeshin. Two-Photon Resonance Mechanism of Optical Pumping of the 8.3 eV 229mTh Isomer in Neutral Atoms. Phys. At. Nucl. 87, 586 (2024)
• F. F. Karpeshin. Laser-assisted two-photon electron-nucleus resonance as applied to producing the 229mTh isomer. Phys. Rev. C 110, 054307 (2024)