The search for the ri_(13/2) vi_(13/2 ) band in ^(178)Ir has been conducted through the ^(152)Sm(^(31) P, 5nγ)^( 178)Ir reaction and the excitation functions, x-γ and γ-γ-t coincidence measurements. Five rotationa...The search for the ri_(13/2) vi_(13/2 ) band in ^(178)Ir has been conducted through the ^(152)Sm(^(31) P, 5nγ)^( 178)Ir reaction and the excitation functions, x-γ and γ-γ-t coincidence measurements. Five rotational bands have been newly identified. The low-spin signature inversion in the πi13/2 vi13/2 band has been confirmed by the observations of linking transitions and signature crossing at I = 25.5 h. The inversion phenomenon in rh11/2 vi_(13/2), rh9/2 vi_(13/2) and ri_(13/2) vi13/2 structures in ^(178)Ir provides a unique testing ground for different theoretical interpretations.展开更多
The high-spin level structure of 186 Au is re-investigated by means of in-beam γ-ray spectroscopy via the 172 Yb(19 F,5nγ )186 Au reaction.The oblate bands previously reported are revised and extended to higher-spin...The high-spin level structure of 186 Au is re-investigated by means of in-beam γ-ray spectroscopy via the 172 Yb(19 F,5nγ )186 Au reaction.The oblate bands previously reported are revised and extended to higher-spin states.A new Iπ =(20+) excited state has been identified and assigned to the πh-111/2 (×) vi-213/2h-19/2 configuration.The total Routhian surface and cranked shell model calculations suggest that the πh-111/2 (×) vi-213/2h-19/2 band in 186Au has a non-axial deformation.展开更多
The Excited states of ^(88)Sr have been produced in the reaction ^(16)O(^(82)Se,4p6n)and studied using the in-beam γ spectroscopy techniques.Two high-spin level structures have been observed and established up to 8.5...The Excited states of ^(88)Sr have been produced in the reaction ^(16)O(^(82)Se,4p6n)and studied using the in-beam γ spectroscopy techniques.Two high-spin level structures have been observed and established up to 8.5 MeV and 7.9 MeV excitation energy,respectively.Based on the measurements of the directional correlations ofγ-rays de-exciting oriented states and anisotropic factors ofγ-rays,spin values of the excited states have been assigned up to the highest levels observed.展开更多
High-spin states in 178'180Ir have been studied via the 152'154Sm(31P,5nγ)reactions through excitation functions,x-γandγ-γ-t coincidence measurements.A doubly decoupled band has been identified in each of ...High-spin states in 178'180Ir have been studied via the 152'154Sm(31P,5nγ)reactions through excitation functions,x-γandγ-γ-t coincidence measurements.A doubly decoupled band has been identified in each of the isotopes.The level spacings for such structures in odd-odd ^(178-186)Ir have been inspected and thus a regular level staggering as a function of the neutron number is revealed.This particular phenomenon may be associated with bandmixing at lower excitation energies.展开更多
High-spin states of odd-odd^(182)Au has been studied for the first time,by USing^(152)Sm(^(35)Cl,5n)^(182)Au reaction at 183MeV beam energy.The^(35)Cl beam was provided by the JAERI(Japan Atomic Energy Research Instit...High-spin states of odd-odd^(182)Au has been studied for the first time,by USing^(152)Sm(^(35)Cl,5n)^(182)Au reaction at 183MeV beam energy.The^(35)Cl beam was provided by the JAERI(Japan Atomic Energy Research Institute)tandem accelerator.The target is an enriched^(152)Sm metallic fon of 1 mg/cm^2 thickhess with 5 mg/cm^2展开更多
Low-spin signature inversion in theπh9/2■vi_(13/2)band was reported for the first time by Bark et al.~[1]in^(162,164)Tm and^(174)Ta in 1997.Since then,this inversion phenomenon has been found in several neighboring ...Low-spin signature inversion in theπh9/2■vi_(13/2)band was reported for the first time by Bark et al.~[1]in^(162,164)Tm and^(174)Ta in 1997.Since then,this inversion phenomenon has been found in several neighboring odd-odd nuclei.During the past few years,we have made great efforts to investigate the band structures in odd-odd nuclei in this mass rgion,leading to observation of signature invesion in^(170)Ta,^(172)Re,^(176~280)Ir and ^(182)Au,respectively.展开更多
We established the level scheme of 145Tb for the first time. The excited states below 2 MeV have been interpreted qualitatively by coupling an h11/2 valence proton to the 0+, 2+, 4+ and 3- excited states in the 144Gd ...We established the level scheme of 145Tb for the first time. The excited states below 2 MeV have been interpreted qualitatively by coupling an h11/2 valence proton to the 0+, 2+, 4+ and 3- excited states in the 144Gd core nucleus, and the yrast levels in excitation energy range from 2.1 to 3.4 MeV have been suggested from the (πh211/2d-15/2/g-17/2) proton excitations or the couplings of the h11/2 proton to the 5- and 7-展开更多
High-spin states of odd-odd 172Re has been studied, for the first time, by using 149Sm(27Al, 4n) 172Re reaction. The 27A1 beam was provided by the JAERI (Japan Atomic Energy Research Institute) tandem accelerator. The...High-spin states of odd-odd 172Re has been studied, for the first time, by using 149Sm(27Al, 4n) 172Re reaction. The 27A1 beam was provided by the JAERI (Japan Atomic Energy Research Institute) tandem accelerator. The target was an enriched 149Sm metallic powder of 2.1 mg/cm2 thickness evaporated on to a 5.5 mg/cm2 Pb backing layer. A γ-ray detector array was used comprising 12 HPGe's with BGO展开更多
The N=82 136Ba nucleus has a proton number between the Z=50 and Z=64 shell closures. Thus it is interesting to obtain detailed spectroscopic information on low-lying states in 136Ba. Such experimental information is i...The N=82 136Ba nucleus has a proton number between the Z=50 and Z=64 shell closures. Thus it is interesting to obtain detailed spectroscopic information on low-lying states in 136Ba. Such experimental information is important to achieve a unified description of nuclei based on shell model with multiparticle space.展开更多
High-spin states in 169Re have been investigated by means of in-beam 7-ray spectroscopy techniques with the 144Sm(28Si, 1p2n) 169Re reaction. X-γ and γ-γ-t coincidences, 7-ray anisotropies, and DCO ratios were meas...High-spin states in 169Re have been investigated by means of in-beam 7-ray spectroscopy techniques with the 144Sm(28Si, 1p2n) 169Re reaction. X-γ and γ-γ-t coincidences, 7-ray anisotropies, and DCO ratios were measured. A strongly coupled band based on the 9/2-[514] Nilsson state and a decoupled band built on the h9/2 intruder proton orbital (nominally 1/2- [541]) have been established. The AB neutron crossings are observed at hω=0.23 and 0.27 MeV for the 9/2-[514] and 1/2-[541] bands, respectively. The difference between展开更多
The level structure of doubly odd nucleus 146Tb has been studied via the 118Sn(32S, 1p 3n)146Tb reaction by using techniques of in-beam γ-iay spectroscopy. Measurements of 7-ray excitation functions, 7-ray anisotropi...The level structure of doubly odd nucleus 146Tb has been studied via the 118Sn(32S, 1p 3n)146Tb reaction by using techniques of in-beam γ-iay spectroscopy. Measurements of 7-ray excitation functions, 7-ray anisotropies, X-γ and γ-γ-t coincidences were performed with 12 BGO(AC)HPGe detectors. Based on the γ-γ coincidence relationships, intensity balances and cross-over transitions, the level scheme of 146Tb has been extended up展开更多
Study of in-beam γ-ray spectroscopy of ^145Tb has been carried out by using ^118Sn (32 S, 1p4n) ^145Tb reaction. Excitation functions, X-γ-t and γ-γ-t coincidences and γ-ray anisotropies were measured. Here, t re...Study of in-beam γ-ray spectroscopy of ^145Tb has been carried out by using ^118Sn (32 S, 1p4n) ^145Tb reaction. Excitation functions, X-γ-t and γ-γ-t coincidences and γ-ray anisotropies were measured. Here, t refers to the relative time difference between any two coincident γ-rays detected within ±200 ns. A level scheme of ^14tTb, including 81 γ-transitions as shown in Fig.l, has been established up to 7.4 MeV in excitation energy and spinparity assignments for most of the observed levels have been done. The level structure shows characteristics of spherical nucleus. The observed states with excitation energies less than 2 MeV are interpreted by coupling an h11/2 proton to the 2^+, 4^+ and 3^- core excitations in ^144Gd. The excitation energies of these states fit wellin to the systematics of the neighboring odd-A N=80 isotones, and are well reproduced by the quasiparticle-cluster interaction calculations[1]. Semi-empirical shell model calculations[2] have been done for the higher-lying levels. The results clearly reveal the characteristic features of multiparticle configurations in a spherical nucleus. Specific configurations are proposed for the yrast and some non-yrast levels.展开更多
High-spin states in ^179Au have been studied experimentally by using the ^149Sm(^35C1, 5n) reaction at beam energies of 164,~180 MeV. The ^35C1 beam was provided by the tandem accelerator at the Japan Atomic En-ergy R...High-spin states in ^179Au have been studied experimentally by using the ^149Sm(^35C1, 5n) reaction at beam energies of 164,~180 MeV. The ^35C1 beam was provided by the tandem accelerator at the Japan Atomic En-ergy Research Institute (JAERI). The target is an isotopically enriched ^149Sm metallic foil of 1.5 mg/cm^2 thickness with a 5.0 mg/cm^2 Pb backing. Measurements of γ-ray excitation functions, X-γ coincidences and γ-γ-t coincidences were performed with 13 HPGe's with BGO anti-Compton shields and three LOAX detectors.展开更多
High-spin states of odd-odd^(176)Ir has been studied for the first time,by using^(149)Sm(^(31)P,4n)^(176)Ir reaction.The^(31)P beam was provided by the JAERI(Japan Atomic Energy Research Institute)tandem accelerator.T...High-spin states of odd-odd^(176)Ir has been studied for the first time,by using^(149)Sm(^(31)P,4n)^(176)Ir reaction.The^(31)P beam was provided by the JAERI(Japan Atomic Energy Research Institute)tandem accelerator.The target was an enriched^(149)Sm metallic powder of 2.1 mg/cm^(2) thickness evaporated on to a 5.5mg/cm^(2) Pb backing layer.展开更多
Low-spin signature inversion is a very interesting phenomenon observed in a number of deformed odd-odd nuclei and it has been attracting large experimental and theoretical interests.Up to date,the signature inversion ...Low-spin signature inversion is a very interesting phenomenon observed in a number of deformed odd-odd nuclei and it has been attracting large experimental and theoretical interests.Up to date,the signature inversion has been systematically observed throughout the chart of nuclides in theπg_(9/2)■vg_(9/2),πh_(11/2),πh_(11/2)■vi_(13/2),andπh_(9/2)■vi_(13/2)configurations.展开更多
High-spin states of odd-odd^(178)Ir has been studied by using^(152)Sm(^(31)P,5n)^(178)Ir reaction.The^(31)P bcam was provided by the JAERI(Japan Atomic Enetgy Research Institute)tandem acceelerator.The target is an en...High-spin states of odd-odd^(178)Ir has been studied by using^(152)Sm(^(31)P,5n)^(178)Ir reaction.The^(31)P bcam was provided by the JAERI(Japan Atomic Enetgy Research Institute)tandem acceelerator.The target is an enriched^(152)Sm metallic foil of 1 mg/cm^2 thickness with 5 mg/cm^2 Au backing.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.10025525 and 19605008the Japan STA Scientist Exchange Programme,the JSPS Invitation Fellowship Programme for Research in Japan under Grant No.L00515the Major State Basic Research Development Programme of China(Contract No.G2000077400).
文摘The search for the ri_(13/2) vi_(13/2 ) band in ^(178)Ir has been conducted through the ^(152)Sm(^(31) P, 5nγ)^( 178)Ir reaction and the excitation functions, x-γ and γ-γ-t coincidence measurements. Five rotational bands have been newly identified. The low-spin signature inversion in the πi13/2 vi13/2 band has been confirmed by the observations of linking transitions and signature crossing at I = 25.5 h. The inversion phenomenon in rh11/2 vi_(13/2), rh9/2 vi_(13/2) and ri_(13/2) vi13/2 structures in ^(178)Ir provides a unique testing ground for different theoretical interpretations.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10905075,10825522,10735010,and 10975006the National Basic Research Program of China under Grant No 2007CB815005the Chinese Academy of Sciences.
文摘The high-spin level structure of 186 Au is re-investigated by means of in-beam γ-ray spectroscopy via the 172 Yb(19 F,5nγ )186 Au reaction.The oblate bands previously reported are revised and extended to higher-spin states.A new Iπ =(20+) excited state has been identified and assigned to the πh-111/2 (×) vi-213/2h-19/2 configuration.The total Routhian surface and cranked shell model calculations suggest that the πh-111/2 (×) vi-213/2h-19/2 band in 186Au has a non-axial deformation.
基金Supported by the National Natural Science Foundation of China under Grant Nos.19705011 and 19635030the Chinese Academy of Sciences,and RIKEN Radiation Laboratory。
文摘The Excited states of ^(88)Sr have been produced in the reaction ^(16)O(^(82)Se,4p6n)and studied using the in-beam γ spectroscopy techniques.Two high-spin level structures have been observed and established up to 8.5 MeV and 7.9 MeV excitation energy,respectively.Based on the measurements of the directional correlations ofγ-rays de-exciting oriented states and anisotropic factors ofγ-rays,spin values of the excited states have been assigned up to the highest levels observed.
基金Supported by Japan STA(Science and Technology Agency)Scientist Exchange Program(Grant No.1998-21)the National Natrural Science Foundation of China under Grant No.19605008.
文摘High-spin states in 178'180Ir have been studied via the 152'154Sm(31P,5nγ)reactions through excitation functions,x-γandγ-γ-t coincidence measurements.A doubly decoupled band has been identified in each of the isotopes.The level spacings for such structures in odd-odd ^(178-186)Ir have been inspected and thus a regular level staggering as a function of the neutron number is revealed.This particular phenomenon may be associated with bandmixing at lower excitation energies.
基金Supported by NNSF of China,STA Scientist Exchange Program and Major State Basic Research Development Program of China.
文摘High-spin states of odd-odd^(182)Au has been studied for the first time,by USing^(152)Sm(^(35)Cl,5n)^(182)Au reaction at 183MeV beam energy.The^(35)Cl beam was provided by the JAERI(Japan Atomic Energy Research Institute)tandem accelerator.The target is an enriched^(152)Sm metallic fon of 1 mg/cm^2 thickhess with 5 mg/cm^2
基金Supported by NNSF of China,STA Scientist Exchange Program and Major State Basic Research Development Program of China.
文摘Low-spin signature inversion in theπh9/2■vi_(13/2)band was reported for the first time by Bark et al.~[1]in^(162,164)Tm and^(174)Ta in 1997.Since then,this inversion phenomenon has been found in several neighboring odd-odd nuclei.During the past few years,we have made great efforts to investigate the band structures in odd-odd nuclei in this mass rgion,leading to observation of signature invesion in^(170)Ta,^(172)Re,^(176~280)Ir and ^(182)Au,respectively.
文摘We established the level scheme of 145Tb for the first time. The excited states below 2 MeV have been interpreted qualitatively by coupling an h11/2 valence proton to the 0+, 2+, 4+ and 3- excited states in the 144Gd core nucleus, and the yrast levels in excitation energy range from 2.1 to 3.4 MeV have been suggested from the (πh211/2d-15/2/g-17/2) proton excitations or the couplings of the h11/2 proton to the 5- and 7-
基金Supported by NNSF of China, the Major State Basic Research Development Program of China and the Chinese Academy of Sciences.
文摘High-spin states of odd-odd 172Re has been studied, for the first time, by using 149Sm(27Al, 4n) 172Re reaction. The 27A1 beam was provided by the JAERI (Japan Atomic Energy Research Institute) tandem accelerator. The target was an enriched 149Sm metallic powder of 2.1 mg/cm2 thickness evaporated on to a 5.5 mg/cm2 Pb backing layer. A γ-ray detector array was used comprising 12 HPGe's with BGO
文摘The N=82 136Ba nucleus has a proton number between the Z=50 and Z=64 shell closures. Thus it is interesting to obtain detailed spectroscopic information on low-lying states in 136Ba. Such experimental information is important to achieve a unified description of nuclei based on shell model with multiparticle space.
文摘High-spin states in 169Re have been investigated by means of in-beam 7-ray spectroscopy techniques with the 144Sm(28Si, 1p2n) 169Re reaction. X-γ and γ-γ-t coincidences, 7-ray anisotropies, and DCO ratios were measured. A strongly coupled band based on the 9/2-[514] Nilsson state and a decoupled band built on the h9/2 intruder proton orbital (nominally 1/2- [541]) have been established. The AB neutron crossings are observed at hω=0.23 and 0.27 MeV for the 9/2-[514] and 1/2-[541] bands, respectively. The difference between
基金Supported by NSFC and Major State Basic Research Development Program.
文摘The level structure of doubly odd nucleus 146Tb has been studied via the 118Sn(32S, 1p 3n)146Tb reaction by using techniques of in-beam γ-iay spectroscopy. Measurements of 7-ray excitation functions, 7-ray anisotropies, X-γ and γ-γ-t coincidences were performed with 12 BGO(AC)HPGe detectors. Based on the γ-γ coincidence relationships, intensity balances and cross-over transitions, the level scheme of 146Tb has been extended up
文摘Study of in-beam γ-ray spectroscopy of ^145Tb has been carried out by using ^118Sn (32 S, 1p4n) ^145Tb reaction. Excitation functions, X-γ-t and γ-γ-t coincidences and γ-ray anisotropies were measured. Here, t refers to the relative time difference between any two coincident γ-rays detected within ±200 ns. A level scheme of ^14tTb, including 81 γ-transitions as shown in Fig.l, has been established up to 7.4 MeV in excitation energy and spinparity assignments for most of the observed levels have been done. The level structure shows characteristics of spherical nucleus. The observed states with excitation energies less than 2 MeV are interpreted by coupling an h11/2 proton to the 2^+, 4^+ and 3^- core excitations in ^144Gd. The excitation energies of these states fit wellin to the systematics of the neighboring odd-A N=80 isotones, and are well reproduced by the quasiparticle-cluster interaction calculations[1]. Semi-empirical shell model calculations[2] have been done for the higher-lying levels. The results clearly reveal the characteristic features of multiparticle configurations in a spherical nucleus. Specific configurations are proposed for the yrast and some non-yrast levels.
文摘High-spin states in ^179Au have been studied experimentally by using the ^149Sm(^35C1, 5n) reaction at beam energies of 164,~180 MeV. The ^35C1 beam was provided by the tandem accelerator at the Japan Atomic En-ergy Research Institute (JAERI). The target is an isotopically enriched ^149Sm metallic foil of 1.5 mg/cm^2 thickness with a 5.0 mg/cm^2 Pb backing. Measurements of γ-ray excitation functions, X-γ coincidences and γ-γ-t coincidences were performed with 13 HPGe's with BGO anti-Compton shields and three LOAX detectors.
基金Supported by NNSF of China,the Major State Basic Research Development Program of China,and the Chinese Academy of Sciences.
文摘High-spin states of odd-odd^(176)Ir has been studied for the first time,by using^(149)Sm(^(31)P,4n)^(176)Ir reaction.The^(31)P beam was provided by the JAERI(Japan Atomic Energy Research Institute)tandem accelerator.The target was an enriched^(149)Sm metallic powder of 2.1 mg/cm^(2) thickness evaporated on to a 5.5mg/cm^(2) Pb backing layer.
基金Supported by NNSF of China,STA Scientist Exchange ProgramMajor State Basic Research Development Program of China.
文摘Low-spin signature inversion is a very interesting phenomenon observed in a number of deformed odd-odd nuclei and it has been attracting large experimental and theoretical interests.Up to date,the signature inversion has been systematically observed throughout the chart of nuclides in theπg_(9/2)■vg_(9/2),πh_(11/2),πh_(11/2)■vi_(13/2),andπh_(9/2)■vi_(13/2)configurations.
基金Supported by NNSF of ChinaSTA Scientist Exchange ProgramMajor State Basic Research Development Program of China.
文摘High-spin states of odd-odd^(178)Ir has been studied by using^(152)Sm(^(31)P,5n)^(178)Ir reaction.The^(31)P bcam was provided by the JAERI(Japan Atomic Enetgy Research Institute)tandem acceelerator.The target is an enriched^(152)Sm metallic foil of 1 mg/cm^2 thickness with 5 mg/cm^2 Au backing.
