Parity nonconservation in the circular polarization of primary photons of the radiation accompanying electron conversion in the 5/2- → 5/2+ nuclear transition in the 229Pa91 nucleus

The ground state of Pa-229(91) is a 5/2(+/-) doublet, with the splitting energy being 220 +/- 50 cV, A direct observation of P-odd effects in this system is of great interest, since this may furnish information about the parity-nonconserving effective one-nucleon potential. Since a transition between two opposite parity doublet states is accompanied by a strong conversion, it is possible to study P-odd mixing by exploring the conversion-electron helicity and the circular polarization P-gamma of the lines of atomic radiation that arises upon the filling of a hole in the 6s(1/2), 6p(1/2) and 6p(3/2) shells of the Pa-229(91) atom. Since P-gamma is about 3-5% For individual atomic transitions, experiments aimed at observing parity-nonconservation effects on this basis are feasible. (C) 2001 MAIK "Nauka/Interperiodica".