Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

PHOTONUCLEAR ACTIVATION BY 20.5-Mev GAMMA RAYS

Journal Article · · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D
The photonuclear activation cross section of elements whose ( gamma ,n) cross sections lead to a suitable positron activity is measured using monochromatic gamma rays from the T3(p, gamma )He4 reaction, The gamma rays are monitored by a 3-in. diam by 4-in. long sodlum iodide crystal and calibrated with a 41/2 x 6 in. crystal whose response curve to the gamma rays is determined. The absorption coefficient of these photons in NaI is determined by a good- geometry transmission experiment. The positron activlty is determined by a coincldence detector, consisting of two 5-in. diam by 2-in. long NaI crystals set on the annihilation radiation photopeaks. This detector is calibrated against a F/sup 18/. positron source standardized in a 2 pi flow couster, The 20.1 to 21.2 Mev. Structure is not observed. The ( gamma ,n) activation cross section is measured at 20.5 Mev for O/sup 16/, Cr/sup 50/, fe/sup 54/, Cu/sup 63/, Zn/sup 64/ , Mo/sup 92, sb/sup 121/ and Pr/sup 141/, giving cross sections of 0.60 plus or minus 0.12, 29.1 P 6.0, 30.0 plus or minus 4.8, 52.5 plus or minus 2.5, 35,7 plus or minus l.8, 35,4 plus or minus 2.5, 33.4 2.7, 51.7 plus or minus 5.5barns, respectively. (auth)
Research Organization:
Univ. of Pennsylvania, Philadelphia
NSA Number:
NSA-16-018512
OSTI ID:
4840726
Journal Information:
Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Journal Name: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D Vol. Vol: 126; ISSN PHRVA
Country of Publication:
Country unknown/Code not available
Language:
English