value in Kr
Rgis, J.-M.*; Jolie, J.*; Saed-Samii, N.*; Warr, N.*; Pfeiffer, M.*; Blanc, A.*; Jentschel, M.*; Kster, U.*; Mutti, P.*; Soldner, T.*; Simpson, G. S.*; Drouet, F.*; Vancraeyenest, A.*; de France, G.*; Clment, E.*; Stezowski, O.*; Ur, C. A.*; Urban, W.*; Regan, P. H.*; Podolyk, Zs.*; Larijani, C.*; Townsley, C.*; Carroll, R.*; Wilson, E.*; Fraile, L. M.*; Mach, H.*; Paziy, V.*; Olaizola, B.*; Vedia, V.*; Bruce, A. M.*; Roberts, O. J.*; Smith, J. F.*; Krll, T.*; Hartig, A.-L.*; Ignatov, A.*; Ilieva, S.*; Thrauf, M.*; Lalkovski, S.*; Ivanova, D.*; Kisyov, S.*; Korten, W.*; Salsac, M.-D.*; Zieliska, M.*; Mrginean, N.*; Ghit, D. G.*; Lic, R.*; Petrache, C. M.*; Astier, A.*; Lguillon, R.
A smooth onset of collectivity in Kr has been determined from reported and E(2) values. This is in contrast to the sudden onset in even-even Zr, Mo, and Sr isotopes. Our objective was to complete the systematics by determining the value in Kr, which was produced by cold-neutron-induced fission of U. The lifetime of the 2 state in Kr was measured via the electronic timing technique using the EXILL and FATIMA spectrometers. Based on the measured mean lifetime of = 15(10) ps, the value of 13 W.u. in Kr is determined for the first time and the smooth onset of deformation in the even-even Kr isotopes beyond neutron number N=50 is confirmed.