A short-lived metastable state in titanium-46

Abstract

Benedetti and McGowan, Mandeville and Scherb and Hirzel, Stoll and Wäffler have attempted to detect short-lived metastable states of radioactive nuclei by using the method of delayed β-β and β-γ coincidences. Several decay periods have been detected by these methods. We have examined delayed γ-γ coincidences using a method similar to that used by Bunyan et al.4, but with two counting channels instead of one. The delay of one of the channels is kept fixed and is called the fixed channel. The γ-counters were kept symmetrically with respect to the source and had sufficient thickness of matter to cut down all β-rays below 1.7 MeV. The γ-counters, 3 cm. long and 2 cm. in diameter, were filled with a standard argon and petroleum ether mixture at a pressure of 14 cm. of mercury. The counters had a plateau of 200 volts and the starting potential was 850 volts. Delayed γ-γ coincidences were observed with a source of scandium oxide irradiated with neutrons arranged as in Fig. 1 with respect to the two γ-counters.