Nuclear levels in152Eu

Abstract

The transitional nucleus 152Eu has been studied using the (n, e), (n, 7), (n .... 7), (n, 77), (d,p), (d, t) and (p, d) reactions. The experiments have been performed at nine different laboratories. A model independent level scheme was established including 95 levels below 510 keV and nearly 900 transitions by combination of low energy transitions and reaction data. More than 20 additional levels result from gamma rays and/or charged particle reactions. The level scheme is interpreted in terms of the Nilsson model indicating that 152Eu is a deformed nucleus. Seven rotational bands and Nilsson configurations are established. An additional 27 rotational bands are tentatively or speculatively assugned. Gallagher-Moszkowski splittings are discussed. The neutron binding energy was determined as 6305.2 __ 0.5 keV. The energy of the 9.3h0-isomer is 45.599keV. The lifetimes of four levels were measured.Nuclear Reactions 15tEu(n, 7), E, =thermal and resonance; measured E.~, I~,E ..... I ..... 77 coinc., 77At coinc.; lSlEu(d,p), E=12MeV and 14MeV; a53Eu(d,t), E=12MeV; 153Eu(p,d), E=18MeV; deduced level scheme of 152Eu, J, ~, T1/2, cc, Nilsson configurations. Magnetic electron spectrometer, curved crystal spectrometer, Ge(Li) and Si(Li) detectors, magnetic spectrographs. Enriched targets.

Cross sections and ?-rays from multiple neutron capture in151Eu

“…(2) and (4)) [20] 12,800 (600) 6,305.5 (5) [7,9] 2,300 (1,000) t 52Eu,, + 23,000 intensity variation 11,u00 _ 11,000 absolute intensities ..... + 14,000 tl,uuu 5,500 [4] 68,000 (14,000) [19] < 20,000 larger than previous values which had a systematic calibration error of a factor of two. The deduced excitation energies in Table 3 are in good agreement with the levels in t52Eu [6] and will help to extend the very complicated level scheme of ~52Eu to higher energies. The neutron binding energy of 152Eu was determined with the strongest primary transitions (corrected for recoil) and the corresponding level energies [63.…”

“…Since the cross sections of 151Eu, l S}Eug and 152Eu" are >6,000b, they can be observed by single and double neutron capture in lSlEu. The ground state and the isomer of 152Eu have the following spins, parities and half lives [6,7] : 152Eug : I~=3 , T1/2 =(13.33_+0.04)a, 152Eum(45.599 keV): I~=0-, T~/2= (9.32_+0.01)h.…”

Levels in154Eu populated by thermal neutron capture

“…Hindrance factors can be determined by comparison with the Weisskopf estimate[30]. Some information might be obtained by comparison with lSZEu[32] which is considered to have a very similar structure.The ground state of 152Eu has the configuration p5/2 + [413~] -n11/2-[,5051"]. The new value 8.5 y, reported byEmery [,31] is only a tentative value and might be wrong.…”

Transfer and neutron capture reactions toIr194as a test of Uν(6/Balodis1, Wirth2, Graw3 et al. 2008Phys. Rev. C14040View full textAdd to dashboardCite

“…Comments on previous investigations of 194 Ir and other transitional nuclei such as 192 Ir, 196 Au, and 152 Eu may be of interest [1,[20][21][22]. In this subsection, we emphasize the general approaches to the present development of the 194 Ir level scheme.…”