TY - JOUR AU - Romanenko, V.I. AU - Udovitskaya, Ye.G. AU - Yatsenko, L.P. AU - Romanenko, A.V. AU - Litvinov, A.N. AU - Kazakov, G.A. PY - 2021/12/03 Y2 - 2024/03/28 TI - Direct Two-Photon Excitation of Isomeric Transition in Thorium-229 Nucleus JF - Ukrainian Journal of Physics JA - Ukr. J. Phys. VL - 57 IS - 11 SE - Optics, lasers, and quantum electronics DO - 10.15407/ujpe57.11.1119 UR - https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2021151 SP - 1119 AB - <p>A possibility of the two-photon excitation of an isomeric state in a nucleus of thorium-229 has been discussed. The fluorescence intensity of the excitation is demonstrated to be identical for the irradiation of nuclei with either monochromatic light or polychromatic radiation consisting of a sequence of short light<br>pulses of the same intensity. The two-photon excitation of Th<sup>3+</sup> ion in an electromagnetic trap with a focused laser beam with a wavelength of about 320 nm and power of 100 mW can lead to the absorption saturation, at which the fluorescence emission with the frequency of the transition in a nucleus is maximal. In crystals doped with Th<sup>4+</sup> to a concentration of about 10<sup>18 </sup>cm<sup>-3</sup> and irradiated with a laser radiation 10 W in power, the emission of several photons per<br>second with a wavelength of about 160 nm becomes possible.</p> ER -