THE NEW ISOTOPES Cd104 AND Ag104

Abstract

Two new neutron deficient isotopes Cd¹⁰⁴ (59 min.) and Ag¹⁰⁴ (27 min.) have been produced by the reaction Ag¹⁰⁷(p, 4n)Cd¹⁰⁴ at 50 Mev. in the McGill University synchrocyclotron and by the subsequent growth of silver from the cadmium. These isotopes have been investigated by means of a 180° spectrograph of high resolution, a lens spectrometer, and a scintillation spectrometer. Chemical methods of identification have also been employed. Ag¹⁰⁴ has been found to emit a positron spectrum of end point 2.70 ±.01 Mev. and a γ-ray of 556.2 kev. which is thought to be in series with the positron spectrum. The origin of a γ-ray of energy 118.4 kev. which appears to be converted in palladium is at present unknown. A tentative decay scheme is proposed. Cd¹⁰⁴ appears to decay primarily by K-capture since no positron spectrum was observed which could be assigned to this isotope. Four γ-rays, of energies 66.7, 83.6, 123.6, and 134.2 kev., have been definitely assigned to this isotope on the basis of K−L differences shown by conversion lines; on the basis of relative L line intensities and K/L ratios the two low energy γ-rays have been shown to represent M1 transitions. Other conversion lines were found whose origin and element of conversion are unknown.