The production of Be(7), C(11), N(13), or O(15) from carbon, nitrogen and oxygen by 87-mev electrons.

Abstract

Targets of graphite, melamine and water were bombarded with 87- MeV electrons from the Naval Postgraduate School linear accelerator in order to investigate the production of the unstable nuclei Be(7) , C(11) , N(13) , or O(15) from the electromagnetic disintegration of carbon, nitrogen and oxygen. The Be(7) fragments were detected by observing the 477-KeV gamma ray from the daughter nucleus Li(7) . The other disintegration fragments were detected by the annihilation of the emitted positrons which produced 511-KeV photons. A copper radiator was introduced in one-half of the bombardments of each type of nucleus in order to separate the electron and photon effects. Unstable C(11) nuclei were detected as products from all three bombarded nuclei, with electrcdisintegration cross sections ranging from 29.4 yb for carbon to 0.29 yb for oxygen. The N(13) activity resulted from bombardment of both melamine and water, yielding cross sections of 9.43 ub and 0.58 yb for nitrogen and oxygen, respectively. Oxygen has an electrodisintegration cross section of 21.8 yb for production of O(15). Integrated photodisintegration cross sections were found to be 40 to 50 times the above values for the same targets and decay fragments,