Proton induced radioactivities
Abstract
Results are tabulated of the radioactivities produced by 4 Mev protons in targets of 7N, 8O, 20Ca, 24Cr, 27Co, 30Zn, 34Se, 42Mo, 46Pd, 48Cd, 49In. In most cases the reactions are of the p-n type, and lead to isotopes which emit either + or - electrons. A detailed study was made of O, Zn and Se. The reaction O18(p, n)F18 (107 min.) shows a threshold at 2.56 Mev and a positron energy of 0.74 Mev in good agreement with the energy relations. The cross section for the reaction at 4 Mev is about 2×10^-25 cm^2 and there is a resonance maximum at 3.55 Mev. The cross section for the reaction O16(p, γ)F17 is 4000 times smaller. The isomeric Br80 periods (17.4 min. and 4.45 hr.) are observed in the reaction Se80(p, n)Br80. At 4 Mev the ratio of the short to long period activities for infinite bombardment is about 15 but the thresholds are at about 3.0 and 3.2 Mev, respectively. The cross section for the reaction is about 0.6×10^-26 cm^2 at 4 Mev.
Additional Information
©1938 The American Physical Society. Received 27 January 1938. The construction of the cyclotron and related equipment and its continued operation have been made possible by the generous cooperation of many individuals and corporations, to all of whom grateful acknowledgment is made. We wish particularly to express our indebtedness to the Rochester Gas and Electric Company, the Rochester Telephone Company, the Stromberg-Carlson Telephone Manufacturing Company, the Consolidated Machine Tool Corporation, the General Electric Company, the Bell Telephone Laboratories, the American Rolling Mill Company, and the Eastman Kodak Company for supplying equipment, materials, and services at reduced or no cost; to the Research Corporation for financial support; to Dr. A.G. Hill, Mr. George Valley, Mr. Tom Perry and Mr. Arthur Gibson, mechanician, for assistance in construction and operation. We are indebted to Drs. E.O. Lawrence, M.S. Livingston and Donald Cooksey for much valuable advice and assistance in planning and building the cyclotron. Finally we wish to acknowledge the valuable assistance generously given by Professor E.O. Wiig of the chemistry department in planning and carrying out all chemical analyses.Files
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- CaltechAUTHORS:DUBpr38
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2006-11-25Created from EPrint's datestamp field
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2021-11-08Created from EPrint's last_modified field