237 / 2023-04-18 19:37:48

Laser production of nuclear isomer Mo-93m and its astrophysical implication on Mo-92 production

Nuclear isomer 93mMo; 93Nb(p, n)93mMo reaction; Photodisintegration reactions; 93mMo-92Mo reaction flow

极端光下的基础物理学 > QED效应和核物理-I

Nuclear isomer play a key role in the creation of the elements in the universe and have a number of fascinating potential applications related to the controlled release of nuclear energy on demand. Mo-93m has a (21/2)⁺ isomer at 2,425 keV with a half-life of 6.85 h and a (17/2)⁺ intermediate state that lies 4.85 keV higher at 2,430 keV with a half-life of 3.5 ns. Such isomeric property is attractive to exploiting the depletion of nuclear isomers via nuclear excitation by electron capture. In this presentation, we introduce experimental study on laser production of Mo-93m using the XingGuangIII laser facility. The production yield is obtained to be of the order of 10⁶ per laser shot. The resulting peak production efficiency can exceed 10¹⁷ particles per second, which is at least five orders of magnitudes higher than using classical proton accelerator. The effect of nuclear reaction flow on the population of ^93mMo is studied. The ^93mMo involved photodisintegration reactions leading to the production of ⁹²Mo, which is one of the most debated p-nuclei, is further discussed. It is found that the ⁹³Nb(p, n)^93mMo reaction is an important production path for ^93mMo seed nucleus, and the influence of ^93mMo-⁹²Mo reaction flow cannot be ignored.