Low-spin mixed particle–hole structures in 185W

Nuclear structure of 187W studied with (n,γ) and (d,pБондаренко1, Tomandl2, Wirth3 et al. 2008Nuclear Physics ASelf Cite12240View full textAdd to dashboardCite

“…In many cases the experimental cross section and particularly the asymmetry angular distributions are not compatible with any of the expected 'finger print' patterns. These 'anomalous' distributions are similar to that observed in our earlier studies of the odd-mass Hf [32] and W [14] isotopes and are well known in the rare-earth region. They have been explained by interference of one-step and multi-step or inelastic processes.…”

“…We associate the new isomer with Table 1 Energies, absolute intensities and placement of γ -rays above 2 MeV assigned to the 186 W(n, γ ) 187 (8) 2258-0 2013.3 (9) 33 (14) 2090-77 2262.2(7) 21(8) -2018.58 (21) 42(6) d 2322-303 2274.13 (19) 118(16) d 2273-0 2023.33 (25) 64 (6) (20) 152 (19) (4) 68(11) -2290.1 (5) 173 (30) 5467-3176 2033.87 (25) 63 (7) -2291.7 (6) 148(38) d 2497-205 2037.00 (12) 176 (13) 2242-205 2295.3 (6) 86 (16) (17) 120(16) d 2045-0 2301.6(7) 47(11) d 2302-0 2048.4 (13) 27 (11) 2124-77 2308.18 (22) 55 (12) -2055.0 (10) 27 (11) 2260-205 2316.2(3) 65(14) d 2316-0 2061.8 (7) 101 (28) (4) 92 (7) -2333.5 (13) 48 (17) 2411-77 2076.8 (7) 88 (10) (12) 170 (18) 2242-146 2368.8 (6) 62(28) d 2514-146 2100.23 (16) 94 (14) d 2306-205 2371.4 (13) 37 (28) 2370-0 2108.1 (7) 83 …”

“…The outgoing protons were recorded on a 1.8 m long focal plane detector. These measurements have been already used in our earlier paper [14]. An additional (d, p) measurement at 18 MeV with unpolarized deuterons was made for 40 • with the enriched 186 W target which allowed to combine all data for the DWBA analysis.…”

“…All of the measured yields of γ rays after subtraction of the intensity of primary transitions show a rather smooth systematics. Therefore, similar to 185 W [14], in many cases the spin value can be checked by the population systematics. In fact, the population of the 7/2 states gets below the detection limit at energies above 1.4 MeV.…”

“…The quantum numbers of many known states are ambiguous and restrict theoretical interpretations. Primary motivation for the reinvestigation of 187 W by thermal neutron capture was the recent study of 185 W [14] where the high sensitivity of the γ γ coincidence measurements, even considering the small thermal capture cross section for this reaction (1.7 b), allowed us to establish a very detailed decay scheme. Spin-parity assignments were determined by means new (d, p) measurements including polarized deuterons.…”