High-spin states in⁹⁹Rh

Abstract

High-spin states in 99Rh are populated through a fusion evaporation reaction 16O+89Y. A comprehensive level scheme with four bands is made on the basis of coincidence studies and DCO ratios. Placements of several transitions are revised and, together with five new transitions detected in the experiment, two new bands are proposed. Two other bands populated in the previous work are confirmed. The configurations of the three quasiparticle band-head states of the new bands are suggested as ( pi (g92/)3) and ( pi (g92/)* nu (h112/)2).

Band structures in99Rh

“…The previously observed positive-parity band B1 based on the 64 keV isomeric state has been extended up to π I = (45/2 + ). The earlier reported part of band B1 [26,27,36] up to 37/2 + state is confirmed in the present work and new ΔI = 1 dipole (M1) transitions have been observed parallel to the earlier reported ΔI = 2 quadrupole (E2) transitions. The 1052-1206-1073-1128−1198 keV E2 transition sequence reported earlier [27] in the high spin part of band B1 is modified in the present level scheme.…”

“…[301]1 2 orbital. The earlier reported cascade of the 427-552-681-641-813 keV E2 transitions [26,27] and its recent extension by the 985 and 1048 keV transitions by Sugawara et al [36] is confirmed in the present work. The new 1154 and 1376 keV E2 transitions (figure 3(b)) are added to extend band B4 up to ∼8 MeV excitation energy and 37/2 ℏ spin.…”

“…The γ-ray coincidence spectra showing transitions in bands B1-B6 are shown in figures 2-4. The lower part of the present level scheme preserves the features of the single quasiparticle bands B1 and B4 in the previously established schemes [26,27,36].…”

“…The present level scheme of 99 Rh consists of bands labeled as B1-B6. The present level scheme is a considerable 2-dimensional extension with considerable modifications in the earlier reported level schemes [26,27,36]. The γ-ray coincidence spectra showing transitions in bands B1-B6 are shown in figures 2-4.…”

“…Low-lying excited states in 99 Rh up to few MeV have previously been investigated from the β + and EC decay of + 5 2 ground state of 99 Pd (T 1 2 = 21.4 m) [23] and using the light particle transfer reaction 96 Mo( 6 Li,3 γ n ) [24] and the (p, γ n ) reaction [25]. Previous studies based on the heavy-ion induced fusion-evaporation reactions are performed by Kumar et al [26] using the 89 Y( 16 O,α2n) reaction and Singh et al [27] using the 66 Zn( 37 Cl,2p2n) reaction. In these studies, the level structures have been observed up to spin ∼25ℏ and excitation energy ∼10 MeV.…”