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THE RADIOACTIVITY OF Sb$sup 125$ AND Te$sup 125$m. Technical Report No. 2- 9

Technical Report ·
OSTI ID:4209648

The radioactivity of Sb/sup 125/ (2.4 yr) and its daughter, Te/sup 125m/ (58 day), was studied with a double-focusing magnetic spectrometer. Prompt gamma- gamma coincidences in Te/sup 125/ were studied with a sodium iodide scintillation coincidence spectrometer. K conversion intensities, conversion ratios, and properties of the beta spectrum were determined by a study of the electrons emitted by an Sb/sup 125/ source. Transition energies were measured absolutely by a comparison with the standard internal conversion lines of ThB. Gamma-ray transitions and their intensities were determined by examining the secondary electrons elected by the gamma rays from thorium and tantalum converter foils. Some high-resolution studies on the internal conversion lines of Te/sup 125m/ were made. As a result, a total of 16 gamma-ray transitions were found in Te/sup 125/ at energies: consideration of the decay scheme, the relative intensities of the gamma rays and the actual beta spectrum, eight beta-ray transitions were found with end points and intensities: 96 kev (2.2%), 112 kev (<0.8%), 124 kev 443 kev (5.9%) and 619 kev (13.4%). On the basis of prompt gamma-gamma coincidence studies, intensity data, measured internal conversion coefficients, conversion ratios, beta-ray end points, ft values, and the measured transitions energies, a consistent level scheme for Te/sup 125/ is proposed. With these measurements, the multipolarity of the transitions and the spins and parities of the nuclear levels in Te/sup 125/ are determined. The results indicated nuclear states in Te/sup 125/ at energies (spin,and parity in parentheses): 0 kev (1/2 +), 35.6 kev 524.1 kev (7/2- or9/2-), 633.6 kev (5/2+), 639.7 kev (7/2+), 652 kev (?), and 667.8 kev (5/2+). A compsrison of the level scheme of Te/sup 125/ is made with the predictions of several nuclear models. (auth)

Research Organization:
Harvard Univ., Cambridge, Mass. Lyman Lab. of Physics
NSA Number:
NSA-13-021462
OSTI ID:
4209648
Report Number(s):
AECU-4336; AD-217161
Country of Publication:
United States
Language:
English