Optical pumping 229mTh through NEET as a new effective way of producing nuclear isomers

A new highly effective way of optical pumping of the 3.5 eV isomeric state in 229mTh is proposed, allowing one to reach the inverse population of the ground and isomeric state. The way is based on Nuclear Excitation in the nonradiative 8p–8s Electronic Transition (NEET). For this purpose, NEET theory is revised to take energy conservation into account.