Beta Decay of B12
The 3.23-Mev gamma-ray transition between the 7.66 and 4.43-Mev states of C12 has been observed in the beta decay of B12 by means of scintillation detectors and coincidence techniques. The B12 activity was made by the B11 (d,p)B12 reaction using a Van de Graaff accelerator and a beam-chopping system for irradiation and delayed counting. All parts of the target-collimator assembly were constructed of beryllium in order to minimize bremsstrahlung production. Betu rays were detected in an 8''-diam by 1/4''- thick Pilot-B scintillator and gamma rays were detected in two 5'' x 5'' NaI counters placed on opposite sides of the source. Gamma-gamma coincidence measurements were made by displaying the output of each NaI detector in coincidence with a channel centered on the full-energy-loss peak of 4.43-Mev gamma rays in the opposite NaI detector. The additional requirement of a coincidence with the beta-ray detector was imposed for beta-gammagamma coincidence experiments. In both types of measurements the full-energy-loss and one-escape peaks of the 3.23-Mev gamma rays were observed. Based on the average result of two previous nuclear reaction measurements of the fractional decay of the 7.66- Mev state by the emission of 3.23-Mev gamma rays, the present observation of these gamma rays leads to a value of (1.7 plus or minus 0.5)% for the beta-ray branching of B12 to the 7.86-Mev state of C12. (auth)
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- US Atomic Energy Commission (AEC)
- DOE Contract Number:
- AT(30-2)-GEN-16
- NSA Number:
- NSA-17-031511
- OSTI ID:
- 4697964
- Report Number(s):
- BNL-6903; PHRVAO
- Journal Information:
- Physical Review, Vol. 131, Issue 4; Other Information: BNL-6903. Orig. Receipt Date: 31-DEC-63; ISSN 0031-899X
- Country of Publication:
- United States
- Language:
- English
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Beta-ray branching and half-lives of /sup 12/B and /sup 12/N
PROGRESS REPORT FOR APRIL, MAY, JUNE 1959 TO THE UNITED STATES ATOMIC ENERGY COMMISSION
Related Subjects
BERYLLIUM
BETA DECAY
BETA DETECTION
BETA PARTICLES
BORON 11
BORON 12
BRANCHING RATIO
BREMSSTRAHLUNG
CARBON 12
COINCIDENCE METHODS
DEUTERON BEAMS
ENERGY LEVELS
GAMMA RADIATION
IRRADIATION
MEASURED VALUES
NUCLEAR REACTIONS
PROTONS
RADIATION SOURCES
RADIOACTIVITY
SCINTILLATION COUNTERS
TARGETS
VAN DE GRAAFF ACCELERATORS