New neutron-deficient isotopes of barium and rare-earth elements

Discovery of the barium isotopes

“…In the large table of delayed-neutron branching ratios and half-lives the half-life of 149 Ba is quoted as 0.324 (18) s. This value agrees with the currently adopted value of 344 (7) s. Warner and Reeder had reported a half-life measurement for 149 Ba seven years earlier in a conference proceeding [71].…”

“…Bogdanov et al reported the discovery of 117 Ba in 1977 in their article New Neutron-Deficient Isotopes of Barium and Rare-Earth Elements [18]. An enriched 92 Mo target was bombarded with an 180-190 MeV sulfur beam produced by the JINR Laboratory of Nuclear Reactions U-300 Heavy Ion Cyclotron and 117 Ba was produced in the fusion evaporation reaction 92 Mo( 32 S,2p5n).…”

Beta-delayed proton precursors with 59?Z?62

“…A=132: 132pm with a half-life of 4 • 2 s was previously identified by decay analysis of the Nd x-rays associated with electron capture [4]. No delayed proton branch was reported.…”

“…A=129: A B-delayed proton activity with a half-life of 5.9 • 0.6 s at this mass was assigned to 129Nd by Bogdanov et al [4] based on systematics for delayed proton emission. We decided to confirm this result since the high cross section for production of this isotope enabled a thorough study of its decay properties.…”

Decay of neutron deficient Eu, Sm and Pm isotopes near the proton drip line

“…In calculating positron intensities for the decays of 134Sm and 134Pm, the 4-s tape 8 cycle was too short for a reliable Iilulticomponent decay analysis of the 511-ke V intensity, so "'rr-and ,x-coincidence data together with cross section calculations (table 1) were used to confirm the adopted (3+ intensities. The EC intensity in 134Sm decay (calculated from Pm K x rays) was 35(15)% of the total (3-decay intensity.…”