Abstract

In the two-step pumping scheme for a gamma-ray laser, the most uncertain step is that of exciting the nucleus from a long-lived storage isomer to a nearby short-lived state that then decays to the upper lasing level. For a crystalline structure host, the radiation inducing this interlevel transfer step must be used efficiently so as not to destroy the crystal. High-intensity sources of photons are available only for relatively low quantum energy, but it is difficult to couple a long-wavelength photon directly to the very small nucleus. We propose experiments to induce this transfer by first exciting the atomic electrons. We expect nuclear excitation to take place through exchange of a virtual photon in the near field of the electrons. As a test case, the 75-eV^123mU isomer might be excited by electronic motions induced by a bright source UV laser. We propose to detect conversion electrons from the decay of this isomer, measuring the 26-min decay curve.

© 1986 Optical Society of America