Author: C. B. CollinsPublisher:
ISBN:
Category :
Languages : en
Pages : 219
Book Description
The most productive approaches to the problem of the gamma-ray laser have focused upon upconversion techniques in which metastable nuclei are pumped with long wavelength radiation. At the nuclear level the storage of energy can approach tera-Joules (10(exp 12)J) per liter for thousands of years. However, any plan to use such a resource for a gamma-ray laser poses problems of a broad interdisciplinary nature requiring the fusion of concepts taken from relatively unrelated fields of physics. Our research group has described several means through which this energy might be coupled to radiation fields with cross sections for stimulated emission that could reach 10(exp -17)sq cm. Such a stimulated release could lead to output powers as great as 3 x 1021 Watts/liter. Since 1978 we have pursued an approach for the upconversion of longer wavelength radiation incident upon isomeric nuclear populations that can avoid many of the difficulties encountered with traditional concepts of single photon pumping. Experiments have confirmed the general theory and have indicated that a gamma- ray laser is feasible if the right combination of energy levels and branching ratios exists in some real material. Of the 1,886 distinguishable nuclear materials, the present state-of-the-art has been adequate to identify 29 first- class candidates, but further evaluation cannot proceed without remeasurements of nuclear properties with higher precision. Gamma-ray laser, Ultrashort wavelength laser.