The paper studies the effects that arise at the coherent excitation of the anomalously low-lying isomeric level 3/2+(8.19 +/- 0.12 eV) in the 229Th nucleus driven by laser radiation in wide band gap dielectrics. It is shown that in such an excitation a) the appearance of additional decay channels with a width Gamma of the 229mTh isomer due to electron states in the band gap leads to an effective "freezing" of the system in the ground state (the repopulation process at relatively small Gamma and the Zeno effect at large Gamma), making the process of nuclear excitation practically impossible, b) the probability of the alpha decay of a coherent superposition of the ground and isomeric states becomes equal to the half-sum of the alpha widths of both levels and is increased by about a factor of two in comparison with the probability of the alpha decay of 229Th, c) the intensity of the main alpha lines oscillates with the Rabi frequency and the total alpha spectrum shifts towards higher energies for long time measurements, d) the inverse population of nuclear levels required for the Thorium gamma ray laser is achieved relatively quickly within the ir pulse duration, e) the observation of the Zeno effect according to the Cook's scheme is possible for the system of three lower levels of the 229Th nucleus. (c) 2022 Elsevier B.V. All rights reserved.
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