Alpha decay of the new isotopes Po-188,Po-189

Andreyev, AN Ackermann, D Cagarda, P Gerl, J Hessberger, F Hofmann, S Huyse, M Keenan, A Kettunen, H Kleinbohl, A Lavrentiev, A Leino, M Lommel, B Matos, M Munzenberg, G Moore, C O'Leary, CD Page, RD Reshitko, S Saro, S Schlegel, C Schaffner, H Taylor, M Van Duppen, P Weissman, L Wyss, R

An. Andreyev et al., Alpha decay of the new isotopes Po-188,Po-189, EUR PHY J A, 6(4), 1999, pp. 381-385

21

INGLESE

Article

Physics

EUROPEAN PHYSICAL JOURNAL A

1434-6001 → ACNP

6

4

1999

381 - 385

ISI

1434-6001(199912)6:4<381:ADOTNI>2.0.ZU;2-6

New neutron-deficient isotopes Po-188,Po-189 have been produced in the comp lete fusion reaction of Cr-52 ions with a Nd-142 target at the velocity fil ter SHIP. The evaporation residues were separated in-flight and subsequentl y identified on the basis of alpha - gamma and alpha-conversion electron co incidence measurements and of alpha-alpha position and time correlations. I n Po-189 a ground state to ground state alpha decay with E-alpha 1 = 7540(2 0) keV, T-1/2=5(1) ms and two fine structure alpha-decays at E-alpha 2=7264 (15) keV and E-alpha 3=7316(15) keV have been observed. In Po-188 (T-1/2 = 400(-150)(+200) mu s) a ground state to ground state alpha decay at E alpha =7915(25) keV and a fine structure alpha decay at E-alpha=7350(40) keV have been found. Improved data on the alpha-decay of Bi-189 were obtained.