BLACKBODY NUCLEAR SPECTROSCOPY

Up-conversion schemes for a gamma-ray laser would be greatly aided by near-degeneracy of nuclear levels connected by an M1 transition of app reciable strength. We refer to such a transition as an optical nuclear transition. We have investigated mechanisms for locating such states. At present, the best technique would be to heat a sample of the isome r in a blackbody cavity and look for enhanced decays as a result of ph otoexcitation of the nearby state. This would be feasible in the energ y region from 0.1 to 10.0 eV. For energies below about 0.1 eV, the cro ss section is too small for this approach to be feasible. The transiti on could be driven with commercially available coherent sources if the energy is right. Coherent sources tunable over a wide range are expec ted in the fairly near future, at which time the search for optical nu clear transitions could proceed down to very low energy The efforts th at would be required using coherent sources at present seem unwarrante d. Driving the transitions with blackbody radiation, however, should b e a fairly cheap, easy experiment that might produce some interesting nuclear spectroscopy, in addition to advancing the feasibility of the gamma-ray laser.