Proposal for a Nuclear Gamma-Ray Laser of Optical Range

TL;DR

This paper theoretically demonstrates the potential for a gamma-ray laser in the optical range using $^{229m}$Th isomeric nuclei in a crystal, involving nuclear excitation, population inversion, and recoil-free emission.

Contribution

It introduces a theoretical framework for achieving gamma-ray amplification via stimulated emission from thorium nuclei in a dielectric crystal, a novel approach in nuclear laser research.

Findings

Theoretical proof of gamma-ray amplification using $^{229m}$Th nuclei.

Identification of mechanisms for creating nuclear population inversion.

Proposal of a recoil-free emission process in a crystal environment.

Abstract

A possibility of amplification of the 7.6 eV $\gamma$-radiation by the stimulated $\gamma$-emission of the ensemble of the $^{229m}$Th isomeric nuclei in a host dielectric crystal is proved theoretically. This amplification is a result of: 1) the excitation of a large number of the $^{229m}$Th isomers by laser radiation; 2) the creation of the inverse population of nuclear levels in a cooled sample owing to the interaction of thorium nuclei with the crystal electric field or with an external magnetic field; 3) the emissions/absorption of the optical photons by thorium nuclei in the crystal without recoil; 4) the nuclear spin relaxation through the conduction electrons of the metallic covering.