Accession Number:

ADA193856

Title:

Proof of the Feasibility of Coherent and Incoherent Schemes for Pumping a Gamma-Ray Laser

Descriptive Note:

Quarterly technical progress rept. 1 Oct-31 Dec 1987

Corporate Author:

TEXAS UNIV AT DALLAS RICHARDSON CENTERFOR QUANTUM ELECTRONICS

Personal Author(s):

Report Date:

1988-01-01

Pagination or Media Count:

66.0

Abstract:

Recent 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 per liter for thousands of years. This report focuses upon the nuclear analog of the optical double resonance methods which produced much of the database at the molecular level that was of such essential use in the development of conventional lasers. Applied most recently to the study of levels which might be used in dumping isomeric populations into freely radiating states, it produced an unexpected result of major importance. In several test isotopes, a class of extremely useful states was discovered that could radiatively couple to both normal and isomeric states of a nucleus spanning large changes of angular momentum. Achievements culminated in the demonstration of the dumping of population of the first candidate for a gamma-ray laser. One of the least attractive of the isomers because of a large change in angular momentum of 8 h-bar 180Ta superscript m was the only one of the candidates available in milligram quantities. Pumped with the bremsstrahlung from a medical linear accelerator having its maximum output near 2 MeV, and astonishingly large cross section of 40,000 was found on the scale where unity results in a large yield.

Subject Categories:

  • Lasers and Masers
  • Nuclear Physics and Elementary Particle Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE