Efficient production of the nuclear isomer 93mMo with laser-accelerated proton beam and its astrophysical implication on 92Mo production

Nuclear isomers play a key role in the creation of the elements in the universe and potentially have significant applications related to the controlled release of nuclear energy on demand. Particularly, 93mMo is a good candidate for studying the depletion of nuclear isomers via nuclear excitation by electron capture. Therefore, it is necessary to explore the efficient approach of 93mMo production. In this paper, we experimentally demonstrate an efficient production of 93mMo via 93Nb(p, n) reaction induced by an intense laser pulse. Employing the picosecond-duration, 100 J laser pulse, the 93mMo isomer at 2425 keV (21/2+, T1/2 = 6.85 h) is generated with a high yield of 1.8 x 106 particles/shot. The resulting peak production efficiency reaches 1017 particles/s, which is at least five orders of magnitude higher than that obtained using the classical accelerator. The impacts of the production and destruction of 93mMo to the astrophysical p-nuclide 92Mo are studied. It is found that the 93Nb(p, n) 93mMo reaction is an important production path of 93mMo, which could further influence the production of 92Mo. In addition, a direct measurement of the (p, n) reaction rate is proposed using the laser -induced proton beam of which the energies follow the Maxwell-Boltzmann distribution well. It is believed that the laser-induced proton beam opens an avenue for the production of nuclear isomers with high peak efficiency used for the studies of p-nuclei nucleosynthesis.