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The isomer depletion of ^{93m}Mo was recently reported [Chiara et al., Nature (London) 554, 216 (2018)NATUAS0028-083610.1038/nature25483] as the first direct observation of nuclear excitation by electron capture (NEEC). However, the measured excitation probability of 1.0(3)% is far beyond the theoretical expectation. In order to understand the inconsistency between theory and experiment, we produce the ^{93m}Mo nuclei using the ^{12}C(^{86}Kr,5n) reaction at a beam energy of 559 MeV and transport the reaction residues to a detection station far away from the target area employing a secondary beam line. The isomer depletion is expected to occur during the slowdown process of the ions in the stopping material. In such a low γ-ray background environment, the signature of isomer depletion is not observed, and an upper limit of 2×10^{-5} is estimated for the excitation probability. This is consistent with the theoretical expectation. Our findings shed doubt on the previously reported NEEC phenomenon and highlight the necessity and feasibility of further experimental investigations for reexamining the isomer depletion under low γ-ray background.

International audience; Background: Superdeformed (SD) bands are suggested by theory around Ca40 and in lighter alpha-conjugate nuclei such as Mg24, Si28, and S32. Such predictions originate from a number of theoretical models including mean-field models and antisymmetrized molecular dynamics (AMD) calculations. While SD bands have been identified in Ca40 and its near neighbors, evidence of their existence in the lighter, midshell nuclei is circumstantial at best. The key evidence of superdeformation would be the observation of transitions with high B(E2) transition strengths connecting states in a rotational sequence. This is challenging information to obtain since the bands lie at a high excitation energy and competition from out-of-band decay is dominant.Purpose: The purpose of the present study is to establish a new methodology to circumvent the difficulties in identifying and quantifying in-band transitions through directly populating candidate states in the SD band in Si28 through inelastic alpha scattering, selecting such states with a spectrometer, and measuring their gamma-ray decay with a large array of high-purity germanium detectors, allowing direct access to electromagnetic transition strengths.Methods: Excited states in Si28 were populated in the Si28(α,α′) reaction using a 130-MeV He4 beam from the K140 AVF cyclotron at the Research Center for Nuclear Physics. Outgoing alpha particles were analyzed using the Grand Raiden spectrometer positioned at an angle of 9.1∘ to favor the population of states with J≈4. Coincident gamma rays were detected with the CAGRA array of 12 HPGe clover detectors augmented by a set of four large LaBr3 detectors.Results: Data analysis showed that it was possible to identify additional low-energy transitions in competition with high-energy decays from excited states in Si28 in the vicinity of 10 MeV. However, while the candidate 4+ SD state at 10.944 MeV was populated, a 1148-keV transition to the candidate 2+ SD state at 9.796 MeV was not observed, and only an upper limit for its transition strength of B(E2)<43 W.u. could be established. This contradicts AMD predictions of ≈200 W.u. for such a transition.Conclusion: The present study strongly rejects the hypothesis that the candidate set of states identified in Si28 represents an SD band, which demonstrates the potential of the methodology devised here.

Background: Mg 24 is a strongly deformed nucleus in the ground state. Deformation effects can be observed in the structure of the isoscalar giant monopole and quadrupole resonances. Mg 24 is also a nucleus that is well known to present different types of cluster-oscillation modes. Both giant resonances and cluster states are strongly populated by isoscalar transitions. Purpose: To extract the E 0 , E 1 , and E 2 transition strengths via Li 6 scattering. The Li 6 probe is a powerful tool for investigating the isoscalar nuclear response with a very favorable ratio of resonance-to-continuum background. Method: Double-differential cross sections of Li 6 inelastic scattering, at the beam energy of 100 MeV/u, were measured in the excitation-energy range 10 – 40 MeV and scattering angles 0 − 3 ∘ . A multipole-decomposition analysis was performed for extracting the isoscalar E 0 , E 1 , and E 2 strength distributions. Results: The extracted multipole strengths were compared with predictions from consistent quasiparticle random phase approximation calculations. The theoretical predictions are in fair agreement with the experimental data. The E 0 strength was also compared with results from antisymmetrized molecular dynamics calculations found in the literature. A few peaks in the experimental data might be associated with clustering in Mg 24 . Conclusions: Ground-state deformation effects were observed in the isoscalar giant monopole resonance (ISGMR) and isoscalar giant quadrupole resonance (ISGQR) distributions. The ISGMR strength is split in two peaks around 19 and 28 MeV. The ISGQR exhibits a pronounced peak at 20 MeV with a broadening at the low-energy region, similar to predictions from microscopic calculations. Signatures of excitation of cluster states were observed in the E 0 response. Further studies including particle-decay measurements will be required to confirm the nature of the observed peaks.

International audience; The recent paper by Chiara et al. provided the first experimental evidence of nuclear excitation by electron capture (NEEC), responding a long-standing theoretical prediction. NEEC was inferred to be the main channel to excite an isomer in Molybdenum-93 to a higher state, leading to a rapid release of full isomer energy (isomer depletion). The deduced large excitation probability $P_{exc}$=0.010(3) for this mechanism implied strong influence on the survival of nuclei in stellar environments. However, the excitation probability is much higher than the estimated NEEC probability $P_{NEEC}$ according to a following theoretical work by approximately 9 orders of magnitude. Nevertheless, the reported $P_{exc}$ is predicted to be due to other unknown mechanism causing isomer depletion, which is expected to open up a new era of the storage and release of nuclear energy. Here we report an analysis of the reported experimental results, showing that the observed isomer depletion is significantly overestimated due to the contamination.

We report on an isomer yield ratio study of biologically important $^{94}\mathrm{Tc}$ following the fusion of the $^{9}\mathrm{Be}+^{89}\mathrm{Y}$ system, carried out using the offline $\ensuremath{\gamma}$-ray spectroscopy in continuation to the online activation method. The incident beam energies considered are above the Coulomb barrier for the present paper. The platypus model in conjunction with a potential model calculation was employed to analyze the data. An agreement in the order of magnitude between the experimental data and the theoretical predictions has been achieved by applying a phenomenological approach. The approach was further tested with isomer yield ratios of $^{94}\mathrm{Tc}$ formed through $^{3}\mathrm{He}+^{93}\mathrm{Nb}$ reactions. Possible factors that relate to the isomer yield ratios are also presented.

Inelastic ${}^{6}$Li scattering at 100 MeV/u on ${}^{12}$C and ${}^{93}$Nb have been measured with the high-resolution magnetic spectrometer Grand Raiden. The magnetic-rigidity settings of the spectrometer covered excitation energies from 10 to 40 MeV and scattering angles in the range $0^\circ < \theta_{\text{lab.}}< 2^\circ$. The isoscalar giant monopole resonance was selectively excited in the present data. Measurements free of instrumental background and the very favorable resonance-to-continuum ratio of ${}^{6}$Li scattering allowed for precise determination of the $E0$ strengths in ${}^{12}$C and ${}^{93}$Nb. It was found that the monopole strength in ${}^{12}$C exhausts $52 \pm 3^\text{(stat.)} \pm 8 ^\text{(sys.)}$\% of the energy-weighted sum rule (EWSR), which is considerably higher than results from previous $\alpha$-scattering experiments. The monopole strength in ${}^{93}$Nb exhausts $92 \pm 4^\text{(stat.)} \pm 10 ^\text{(sys.)}$\% of the EWSR, and it is consistent with measurements of nuclei with mass number of $A\approx90$. Such comparison indicates that the isoscalar giant monopole resonance distributions in these nuclei are very similar, and no influence due to nuclear structure was observed.

Complete fusion (CF) cross section measurement for the weakly bound 9Be projectile interacting with the intermediate mass target 89Y has been extended to energies greater than the fusion barrier, by implementing off-line characteristic γ -ray detection techniques. The available experimental data for the 9Be + 89Y reaction system were compared with the theoretical predictions, using the PLATYPUS code that is based on a classical dynamical model. By introducing the breakup probability that deduced in the literature from the fitting of the experimental data, the model managed to reproduce the CF cross sections of 9Be beam with targets of different atomic mass. Through the study, it is revealed that the extended CF excitation function for the 9Be + 89Y system is consistent with the systematical behavior that the prompt-breakup probability at above-barrier energies is roughly independent of the target in the reactions induced by the same weakly bound projectiles.

Excited states in the extremely neutron-deficient nucleus $$^{172}{\mathrm {Pt}}$$172Pt were populated via $$^{96}\mathrm {Ru}(^{78}\mathrm {Kr},2p)$$96Ru(78Kr,2p) and $$^{92}\mathrm {Mo}(^{83}\mathrm {Kr},3n)$$92Mo(83Kr,3n) reactions. The level scheme has been extended up to an excitation energy of $$\approx 5~\hbox {MeV}$$≈5MeV and tentative spin-parity assignments up to $$I^\pi = 18^+$$Iπ=18+. Linear polarization and angular distribution measurements were used to determine the electromagnetic E1 character of the dipole transitions connecting the positive-parity ground-state band with an excited side-band, firmly establishing it as a negative-parity band. The lowest member of this negative-parity structure was firmly assigned spin-parity $$3^-$$3-. In addition, we observed an E3 transition from this $$3^-$$3- state to the ground state, providing direct evidence for octupole collectivity in $$^{172}{\mathrm {Pt}}$$172Pt. Large-scale shell model (LSSM) and total Routhian surface (TRS) calculations have been performed, supporting the interpretation of the $$3^-$$3- state as a collective octupole-vibrational state.

The cross sections of complete fusion and incomplete fusion for the $^{9}\mathrm{Be}+^{197}\mathrm{Au}$ system, at energies not too much above the Coulomb barrier, were measured for the first time. The online activation followed by an offline $\ensuremath{\gamma}$-ray spectroscopy method was used for the derivation of the cross sections. A slightly higher value of the incomplete fusion to total fusion ratio has been observed, compared to other systems reported in the literature with a $^{9}\mathrm{Be}$ beam. The experimental data were compared with coupled channel calculations without taking into account the coupling of the breakup channel, and experimental data of other reaction systems with weakly bound projectiles. A complete fusion suppression of about 40% was found for the $^{9}\mathrm{Be}+^{197}\mathrm{Au}$ system, at energies above the barrier, whereas the total fusion cross sections are in agreement with the calculations.

The isomer yield ratios of 184R in the incomplete fusion of the 9Be + 181Ta system were measured at energies around the Coulomb barrier, using online activation followed by offline γ-ray spectroscopy method. The PLATYPUS code that is based on a classical dynamical model is employed to analyze the measurements. By applying a phenomenological approach, model calculation managed to fairly reproduce the order of magnitude of the yield ratios at above barrier energies. Through the study, it is shown that the PLATYPUS code in conjunction with a phenomenological analysis can provide a reasonable explanation of isomer yield ratios resulted from incomplete fusion of weakly bound projectiles.

The 46Ti nucleus has been studied employing the nuclear reaction 12C(36Ar, 2p)46Ti for the first time at a bombarding beam energy of 145 MeV. Lifetimes have been determined employing the Doppler Shift Attenuation Method (DSAM) in low-lying positive-parity levels of yrast band with K π = 0 + . Data were acquired in a γ−γ coincidence measurement with the recently upgraded γ-ray detection array at the Institute of Modern Physics (IMP), Lanzhou. Shell model calculations have been performed using the gxpf1j (GX1J) effective interaction. The interpretation has been given in terms of the large-scale shell model, considering cross-shell particle-hole excitation from d 3 / 2 s 1 / 2 to f 7 / 2 p 3 / 2 orbitals. Reduction in B(E2)'s strength for states above spin 4+, following the enhanced B(E2) at 4+ has been presented. The shell model calculations of B(E2) values are sensitive to the type of interaction (GX1A, GX1J, and KB3) and to the model space.

Background: Inelastic neutrino-nucleus scattering is important for understanding core-collapse supernovae and the detection of emitted neutrinos from such events in earth-based detectors. Direct measurement of the cross sections is difficult and has only been performed on a few nuclei. It is, therefore, important to develop indirect techniques from which the inelastic neutrino-nucleus scattering cross sections can be determined. Purpose: This paper presents a development of the (Li-6,Li-6*[T = 1, T-z = 0, 0(+), 3.56 MeV]) reaction at 100 MeV/u as a probe for isolating the isovector spin-transfer response in the inelastic channel (Delta S = 1, Delta T = 1, Delta T-z = 0) from which the Gamow-Teller transition strengths from nuclei of relevance for inelastic neutrino-nucleus scattering cross sections can be extracted. Method: By measuring the Li-6 ejectile in a magnetic spectrometer and selecting events in which the 3.56 MeV gamma ray from the decay of the Li-6*[3.56 MeV] state is detected, the isovector spin-transfer selectivity is obtained. High-purity germanium clover detectors served to detect the gamma rays. Doppler reconstruction was used to determine the gamma energy in the rest frame of Li-6. From the Li-6 and 3.56 MeV gamma-momentum vectors the excitation energy of the residual nucleus was determined. Results: In the study of the C-12(Li-6,Li-6*[3.56 MeV]) reaction, the isovector spin-transfer excitation-energy spectrum in the inelastic channel was successfully measured. The strong Gamow-Teller state in C-12 at 15.1 MeV was observed. Comparisons with the analog C-12(Li-6,He-6) reaction validate the method of extracting the Gamow-Teller strength. In measurements of the Mg-24, Nb-93(Li-6,Li-6*[3.56 MeV]) reactions, the 3.56 MeV gamma peak could not be isolated from the strong background in the gamma spectrum from the decay of the isoscalar excitations. It is argued that by using a gamma-ray tracking array instead of a clover array, it is feasible to extend the mass range over which the (Li-6,Li-6*) reaction can be used for extracting the isovector spin-transfer response up to mass numbers of similar to 25 and perhaps higher. Conclusions: It is demonstrated that the (Li-6,Li-6*[3.56 MeV]) reaction probe can be used to isolate the inelastic isovector spin-transfer response in nuclei. Application to nuclei with mass numbers of about 25 or more, however, will require a more efficient gamma-ray array with a better tracking capability.

Lifetimes of the first excited 2(+) and 4(+) states in the extremely neutron -deficient nuclide Pt-172 have been measured for the first time using the recoil-distance Doppler shift and recoil-decay tagging techniques. An unusually low value of the ratio B(E2: 4(1)(+) -> 2(1)(+)/B(E2: 2(1)(+) -> 0(gs)(+)) = 0.55(19) was found, similar to a handful of other such anomalous cases observed in the entire Segre chart. The observation adds to a cluster of a few extremely neutron -deficient nuclides of the heavy transition metals with neutron numbers N approximate to 90-94 featuring the effect. No theoretical model calculations reported to date have been able to explain the anomalously low B(E2: 4(1)(+) -> 2(1)(+)/B(E2: 2(1)(+) -> 0(gs)(+)) ratios observed in these cases. Such low values cannot, e.g., be explained within the framework of the geometrical collective model or by algebraic approaches within the interacting boson model framework. It is proposed that the group of B(E2: 4(1)(+) -> 2(1)(+)/B(E2: 2(1)(+) -> 0(gs)(+)) ratios in the extremely neutron-deficient even-even W, Os, and Pt nuclei around neutron numbers N approximate to 90-94 reveal a quantum phase transition from a seniority-conserving structure to a collective regime as a function of neutron number. Although a system governed by seniority symmetry is the only theoretical framework for which such an effect may naturally occur, the phenomenon is highly unexpected for these nuclei that are not situated near closed shells.

International audience; We performed experiments to study the low-energy part of the E1 response (Pygmy Dipole Resonance) in $^{90,94}$Zr nuclei, by measuring the (p,p’γ) and (α,α’γ) inelastic scattering reactions at energies Ebeam,p = 80 MeV and Ebeam,α = 130 MeV respectively. The inelastically scattered particles were measured by employing the high-resolution spectrometer Grand Raiden. The gamma-rays emitted following the de-excitation of the Zr target nuclei were detected using both the clover type HPGe detectors of the CAGRA array and the large volume LaBr3:Ce scintillation detectors from the HECTOR+ array. Some preliminary results are presented here.

Excited states in Re186 with spins up to J=12 were investigated in two separate experiments using W186(d,2n) reactions at beam energies of 12.5 and 14.5 MeV. Two- and threefold γ-ray coincidence data were collected using the CAESAR and CAGRA spectrometers, respectively, each composed of Compton-suppressed high-purity germanium detectors. Analysis of the data revealed rotational bands built on several two-quasiparticle intrinsic states, including a long-lived Kπ=(8+) isomer. Configuration assignments were supported by an analysis of in-band properties, such as gK-gR values. The excitation energies of the observed intrinsic states were compared with results from multi-quasiparticle blocking calculations, based on the Lipkin-Nogami pairing approach, that included contributions from the residual proton-neutron interactions.

Lifetime of the $3/{2}^{\ensuremath{-}}$ first excited state in $^{37}\mathrm{S}$ populated by the ${\ensuremath{\beta}}^{\ensuremath{-}}$ decay of $^{37}\mathrm{P}$ has been measured using $\ensuremath{\beta}\ensuremath{-}\ensuremath{\gamma}$ delayed coincidence technique. The $B(E2;7/{2}^{\ensuremath{-}}\ensuremath{\rightarrow}3/{2}^{\ensuremath{-}})$ value in $^{37}\mathrm{S}$ deduced from the lifetime comes close to the $B(E2;{0}^{+}\ensuremath{\rightarrow}{2}_{1}^{+})$ value in weakly deformed $^{38}\mathrm{S}$ but deviates significantly from that in spherical $^{36}\mathrm{S}$. This manifests that $^{37}\mathrm{S}$ is a weakly deformed rather than spherical nucleus.

利用非完全熔合反应 192 Os( 7 Li, ( p, d, t ) xn )布居了稳定核 195 Pt的高自旋态. 根据 γ - γ 符合关系、 γ 射线的相对强度和各向异性度的测量结果, 建立了 195 Pt核的能级纲图, 其中包括11条新的 γ 跃迁和9个新能级. 通过与邻近核的能级系统性比较, 指出了 195 Pt核基于 vi 13/2 -1 和 vi 13/2 -2 vj -1 ( j = p 3/2 , f 5/2 )组态的转动带能级结构. 同时, 利用Total-Routhian-Surface (TRS)理论计算结果讨论了 195 Pt核的转动带性质.

A new rotational band has been identified and assigned to 188Au for the first time using the 173Yb(19F,4nγ) reaction at the beam energies of 86 and 90 MeV. This band is proposed to be built on the πh 9/2 ⊗ νi 13/2 configuration by comparing the band properties with known bands in neighboring nuclei. The prolate-to-oblate shape transition through triaxial shape has been proposed to occur around 188Au for the ηh 9/2 ⊗ νi 13/2 bands in odd-odd Au isotopes on the basis of total Routhian surface (TRS) calculations.

High-spin states in 161Er have been studied experimentally using the 150Nd(16O, 5n) reaction at a beam energy of 86 MeV. The relatively enhanced E1 transitions between the 5/2+[642] and 3/2−[521] bands are observed in 161Er, and the B(E1) values are extracted experimentally. The systematics of the R(E1) values in the N = 93 isotones are presented. It is found that the strength of the E1 transitions obviously exhibits angular momentum dependence, and the occurrence of the relatively enhanced E1 transitions could be attributed to octupole softness.

We report the results of the measurements of complete and incomplete fusion of the ${}^{9}\text{Be}+{}^{169}\text{Tm}$ and $^{187}\mathrm{Re}$ systems at energies close to the Coulomb barrier. The activation technique with the detection of offline gamma rays was used to derive the cross sections. By comparing the experimental cross sections with coupled-channel calculations that do not include the breakup channel, we found suppression of the complete fusion of the order of 30% for both systems, at energies slightly above the barrier. This suppression corresponds roughly to the measured incomplete fusion. We also investigate a systematic behavior of the suppression of complete fusion cross sections for $^{9}\mathrm{Be}$ on different targets and we found that it does not depend on the target.

One neutron transfer cross sections from the interaction of 9 Be with 89 Y have been measured at energies greater than the fusion barrier. The present measured 1n-transfer cross sections saturate at well above energies in comparison with the available experimental data at lower energies. Results of Coupled Reaction Channels Calculations (CRC) show very good agreement with the present measured cross sections.

Search for low-spin signature inversion in the πi13/2 ⊗ νi13/2 bands in odd-odd 182,184,186 Au has been conducted through the standard in-beam γ-spectroscopy techniques. The experiments for 182 Au and 186 Au have been performed in the Japan Atomic Energy Agency (JAEA) via the 152 Sm (35 Cl ,5 n )182 Au and 172 Yb (19 F ,5 n )186 Au reactions, respectively. A study of 184 Au has been made using a multi-detector array GASP in LNL, Italy, via the 159 Tb (29 Si ,4 n )184 Au reaction. The πi13/2 ⊗ νi13/2 bands in these three nuclei have been identified and extended up to high-spin states. In particular, the inter-band connection between the πi13/2 ⊗ νi13/2 band and the ground-state band in 184 Au has been established, leading to a firm spin-and-parity assignment for the πi13/2 ⊗ νi13/2 band. The low-spin signature inversion is found in the πi13/2 ⊗ νi13/2 bands in 182,184,186 Au according to our spin-assignment and the signature crossing observed at high-spin states.

High-spin band structures in 184Au have been re-investigated using the multidetector array of GASP following the 149Sm(29Si, 4nγ)184Au reaction. Four previously observed bands built on prolate configurations have been extended significantly up to high spins and two weakly populated bands are newly identified. Structure properties of these bands are briefly discussed.

Complete and incomplete fusion cross sections for the $^{9}\mathrm{Be}$ $+\phantom{\rule{0.16em}{0ex}}^{181}\mathrm{Ta}$ system were measured at near barrier energies, using the offline gamma ray spectroscopy method. The results were compared with coupled channel calculations that do not take into account the coupling of the breakup channel, using a double folding potential as bare potential. A complete fusion suppression of the order of 35% was found, at energies above the barrier, whereas the total fusion cross sections are in agreement with the calculations. The ratio between incomplete fusion and total fusion at energies above the Coulomb barrier was found to be $32\ifmmode\pm\else\textpm\fi{}1%$. At sub-barrier energies one observes some enhancement of total fusion cross section.

High-spin level structures of the near-spherical nuclei ${}^{91,92}$Zr have been reinvestigated via the ${}^{82}$Se(${}^{13}$C, $xn$) $(x=4,3)$ reactions at a beam energy of 44 MeV. By the use of in-beam spectroscopic methods, 13 new transitions belonging to ${}^{91}$Zr and 19 to ${}^{92}$Zr have been observed and the level schemes of ${}^{91,92}$Zr have been extended up to ${E}_{x}\ensuremath{\approx}$ 11 MeV excitation energy. The newly constructed level schemes are characterized by the ${}^{88}$Sr core breaking, and the proton ${p}_{3/2}\text{\ensuremath{-}}{p}_{1/2}$ energy gap in ${}^{92}$Zr is obviously reduced compared with ${}^{91}$Zr when one more neutron goes into the $({d}_{5/2}/{g}_{7/2})$ orbital.

The high-spin level structure of the doubly odd nucleus ${}^{104}$Ag has been investigated via the ${}^{97}$Mo(${}^{11}$B, 4n)${}^{104}$Ag reaction at a beam energy of 50 MeV. The newly established level scheme includes lower-lying two-quasiparticle states and several higher-lying bands. Two positive-parity bands associated with the $\ensuremath{\pi}{g}_{9/2}^{\ensuremath{-}1}\ensuremath{\bigotimes}\ensuremath{\nu}{d}_{5/2}$ and $\ensuremath{\pi}{g}_{9/2}^{\ensuremath{-}1}\ensuremath{\bigotimes}\ensuremath{\nu}{g}_{7/2}$ configurations are extended significantly. Based on the comparison with the analogous structures in neighboring nuclei and the features of nuclear chirality, the negative parity bands are suggested as candidate chiral doublet bands with the $\ensuremath{\pi}{g}_{9/2}^{\ensuremath{-}1}\ensuremath{\bigotimes}\ensuremath{\nu}{h}_{11/2}$ configuration.

We have measured the complete fusion, incomplete fusion, and the one-neutron stripping reaction for the ${}^{9}$Be+${}^{186}$W system, at energies not too much above the Coulomb barrier. The online and offline gamma ray spectroscopy methods were used for the derivation of the cross sections. A large value of one-neutron stripping cross section has been observed. The comparison of the data with coupled channel calculations without taking into account the breakup and transfer channels show the usual complete fusion suppression. The possible suppression of the total fusion is discussed.

This paper comprises two separate parts. First, we present the high-spin states in 139Pm nucleus. Two negative-parity dipole bands have been observed and assigned as πh11/2⊗ν(h11/2)−2 and πh11/2⊗ν(h11/2)−4 configurations. From the systematic comparison with neighboring nuclei and SPAC (Shears mechanism with Principal Axis Cranking) model calculations, the two bands can be suggested as magnetic rotational bands. In the other part of this paper, the construction of one new array of eight Clover and sixteen HPGe detectors has been introduced. The characteristics of the Clover detector have been presented and compared with Geant4 simulations.

High-spin states of 194,195Au, 195Pt and 193Ir have been studied using an in-beam γ-ray spectroscopic technique following the reaction of 7Li on an 192Os target at 44 MeV. Several bands in these nuclei have been identified and extended up to high-spin states. The α and t emission channels leading to 193Ir and 195Pt, respectively, are strongly enhanced which may be explained by incomplete fusion reaction; the t and α fragments from the break-up of weakly bound 7Li nucleus fusion with 192Os target.

High-spin states in the odd-odd ${}^{174}$Re have been investigated via the ${}^{152}$Sm(${}^{27\phantom{\rule{-0.16em}{0ex}}}$Al, 5$\mathit{\text{n}}\ensuremath{\gamma}$)${}^{174}$Re reaction with the help of excitation function, x-$\ensuremath{\gamma}$, and $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ coincidence measurements. Five rotational bands have been observed and their configurations were assigned based on alignments, band crossing frequencies, electromagnetic properties, and the estimated bandhead excitation energies. Low-spin signature inversion has been identified in the two-quasiparticle bands built on $\ensuremath{\pi}{h}_{11/2}\ensuremath{\bigotimes}\ensuremath{\nu}{i}_{13/2}$, $\ensuremath{\pi}{h}_{9/2}\ensuremath{\bigotimes}\ensuremath{\nu}{i}_{13/2}$, and $\ensuremath{\pi}1/{2}^{\ensuremath{-}}[541]\ensuremath{\bigotimes}\ensuremath{\nu}5/{2}^{\ensuremath{-}}[512]$ configurations. $E2$ interband transitions were analyzed with band-mixing calculations giving information on shapes and shape driving effects for the bands of interest.

Excited states in ${}^{195}$Au have been studied experimentally via the ${}^{192}$Os(${}^{7}$Li, 4$n$) reaction at a beam energy of 44 MeV. Based on the $\ensuremath{\gamma}$-$\ensuremath{\gamma}$-$t$ coincidence measurement, a level scheme consisting of 15 new transitions and 10 new levels is established for ${}^{195}$Au. The triaxial shape-polarizing effect of the high-$j$ ${h}_{11/2}$ proton hole was studied by total Routhian surface calculations. By comparing with the level structures in the odd-$A$ Au isotopes and the even-even core Hg nuclei, configurations are proposed to the rotational bands and three-quasiparticle states observed in ${}^{195}$Au.

High-spin states in ${}^{139}$Pm are investigated via the ${}^{116}$Cd(${}^{27}$Al, 4$n$)${}^{139}$Pm fusion-evaporation reaction at a beam energy of 120 MeV. The previously reported level scheme has been modified because of identifications of some linking and doublet transitions. The revised yrast $\ensuremath{\pi}{h}_{11/2}$ band obviously undergoes $\ensuremath{\pi}{h}_{11/2}$ $\ensuremath{\rightarrow}$ $\ensuremath{\pi}{({h}_{11/2})}^{3}$ $\ensuremath{\rightarrow}$ $\ensuremath{\pi}{({h}_{11/2})}^{3}$$\ensuremath{\bigotimes}$$\ensuremath{\nu}{({h}_{11/2})}^{\ensuremath{-}2}$ band crossings at $\ensuremath{\hbar}\ensuremath{\omega}=0.45$ and 0.39 MeV. Two negative-parity dipole bands have been assigned as $\ensuremath{\pi}{h}_{11/2}$$\ensuremath{\bigotimes}$$\ensuremath{\nu}{({h}_{11/2})}^{\ensuremath{-}2}$ and $\ensuremath{\pi}{h}_{11/2}$$\ensuremath{\bigotimes}$$\ensuremath{\nu}{({h}_{11/2})}^{\ensuremath{-}4}$ configurations, respectively, and can be considered as examples of magnetic rotational bands.

Excited states in ${}^{165}$Er have been populated using the ${}^{160}$Gd(${}^{9}$Be, 4$n$) reaction at beam energies of 42 and 45 MeV. A band consisting of two levels at excitation energies of 1317.6 and 1505.9 keV, both of which decay strongly to the $11/{2}^{\ensuremath{-}}[505]$ band, is observed and assigned as the $\ensuremath{\gamma}$-vibrational band built on the $11/{2}^{\ensuremath{-}}[505]$ configuration. In addition, a newly identified level is proposed as a three-quasiparticle state.

Excited states of the stable nucleus {sup 195}Pt have been studied using an in-beam {gamma}-ray spectroscopic technique following the incomplete fusion of {sup 7}Li on an {sup 192}Os target at 44 MeV. A level scheme built on the I{sup {pi}=}13/2{sup +} isomer has been established up to I{sup {pi}=}33/2{sup -} at an excitation energy of about 2.6 MeV. Spin and parity values of these states have been assigned from an analysis of anisotropy ratios of {gamma} rays and by analogy with the neighboring nuclei. A comparison of the observed structures with the yrast states in the neighboring even-even {sup 196}Pt core indicates that the identified levels may be regarded as arising from the weak coupling of a {nu}i{sub 13/2} neutron hole to the core states.

Excited states in the stable nucleus $^{193}\mathrm{Ir}$ have been investigated through an in-beam $\ensuremath{\gamma}$-ray spectroscopic technique following the $^{192}\mathrm{Os}$($^{7}\mathrm{Li}$, $\ensuremath{\alpha}2n$) reaction at a beam energy of 44 MeV. A level scheme built on the $\ensuremath{\pi}{h}_{11/2}$ isomer has been extended to high-spin states using eleven newly observed $\ensuremath{\gamma}$ transitions. The $\ensuremath{\pi}{h}_{11/2}$ band is proposed to be formed by coupling an ${h}_{11/2}$ proton to a core with large triaxial deformation. Three-quasiparticle states are suggested in $^{193}\mathrm{Ir}$ on referring to the similar states in $^{187}\mathrm{Ir}$. The features of signature splitting in the $\ensuremath{\pi}{h}_{11/2}$ bands of ${}^{187\ensuremath{-}193}$Ir are discussed with the help of total Routhian surface calculations.

High-spin states in $^{161}\mathrm{Er}$ have been studied experimentally using the $^{150}\mathrm{Nd}$($^{16}\mathrm{O}$,5$\mathit{n}$) reaction at a beam energy of 86 MeV. The $5/{2}^{+}[642]$, $3/{2}^{\ensuremath{-}}[521]$, and $11/{2}^{\ensuremath{-}}[505]$ bands are extended up to high-spin states, and particularly the $\ensuremath{\alpha}=\ensuremath{-}1/2$ branch of the ground state $3/{2}^{\ensuremath{-}}[521]$ band is revised significantly. The relatively enhanced $E1$ transitions from the $3/{2}^{\ensuremath{-}}[521]$ band to the $5/{2}^{+}[642]$ band are observed. The band properties are analyzed within the framework of a triaxial particle-rotor model, and near-prolate shape and triaxial deformation are proposed to the $3/{2}^{\ensuremath{-}}[521]$ and $5/{2}^{+}[642]$ bands, respectively. Signature inversion occurs in the $3/{2}^{\ensuremath{-}}[521]$ band after the band crossing in $^{161}\mathrm{Er}$, and the systematics of the signature inversion associated with the $3/{2}^{\ensuremath{-}}[521]$ configuration are discussed. By analyzing the properties of the relatively enhanced $E1$ transitions, it is found that the $R(E1/E2)$ values show angular momentum dependence before the band crossing, and these enhanced $E1$ transitions could be attributed to octupole softness.

The high-spin level structure of $^{188}\mathrm{Au}$ has been investigated via the $^{173}\mathrm{Yb}$($^{19}\mathrm{F}$,$4n$$\ensuremath{\gamma}$) reaction at beam energies of 86 and 90 MeV. The previously reported level scheme has been modified and extended significantly. A new ${I}^{\ensuremath{\pi}}={20}^{+}$ state associated with $\ensuremath{\pi}{h}_{11/2}^{\ensuremath{-}1}\ensuremath{\bigotimes}\ensuremath{\nu}{i}_{13/2}^{\ensuremath{-}2}{h}_{9/2}^{\ensuremath{-}1}$ configuration and two new rotational bands, one of which is built on the $\ensuremath{\pi}{h}_{9/2}\ensuremath{\bigotimes}\ensuremath{\nu}{i}_{13/2}$ configuration, have been identified. The prolate-to-oblate shape transition through triaxial shape has been proposed to occur around $^{188}\mathrm{Au}$ for the $\ensuremath{\pi}{h}_{9/2}\ensuremath{\bigotimes}\ensuremath{\nu}{i}_{13/2}$ bands in odd-odd Au isotopes. Evidence for $\ensuremath{\pi}{h}_{11/2}^{\ensuremath{-}1}\ensuremath{\bigotimes}\ensuremath{\nu}{i}_{13/2}^{\ensuremath{-}1}$ structure of nonaxial shape with $\ensuremath{\gamma}l\ensuremath{-}{70}^{\ifmmode^\circ\else\textdegree\fi{}}$ has been obtained by comparison with total Routhian surface and cranked-shell-model calculations.