Gamma rays with energies between 80keV and 1500keV produced by 133Ba and 152Eu standard sources are measured with the clover detector.Relative efficiencies and add-back factors are determined in both crystals and full...Gamma rays with energies between 80keV and 1500keV produced by 133Ba and 152Eu standard sources are measured with the clover detector.Relative efficiencies and add-back factors are determined in both crystals and full clover modes.The add-back characteristics have been calculated using Monte-Carlo simulation code Geant4.The simulation and measurements agree very well.展开更多
The (EC+β^(+)) decay of ^(128)Ce was reinvestigated in the^(116)Sn (l6O, 4n) reaction by using a helium-jet tape transport system. The decay γ rays of ^(128)Ce were unambiguously described from those of ^(129)Ce aft...The (EC+β^(+)) decay of ^(128)Ce was reinvestigated in the^(116)Sn (l6O, 4n) reaction by using a helium-jet tape transport system. The decay γ rays of ^(128)Ce were unambiguously described from those of ^(129)Ce after taking the comparing experiments of ^(16)O+^(116)Sn and ^(16)O+^(117)Sn. Based on x-γ and γ-γ coincidence measurements, a detailed (EC+β^(+)) decay scheme of ^(128)Ce has been proposed which modifies the previous one, and takes accounts of 100 observed γ-lines.展开更多
High-spin states of^(119)Xe have been investigated by in-beam γ-ray spectroscopy via the reaction of ^(16)O bombarding a ^(106)Cd target at beam energies of 67-80MeV. No enhanced E1 transition was observed, the non-e...High-spin states of^(119)Xe have been investigated by in-beam γ-ray spectroscopy via the reaction of ^(16)O bombarding a ^(106)Cd target at beam energies of 67-80MeV. No enhanced E1 transition was observed, the non-existence of octupole correlations in ^(119) Xe.展开更多
Two low-lying isomeric states in 169Ta have been identified via ^(159)Tb(l6O,6nγ)^(169)Ta reaction.Their half-lives are measured to be 28±5ns for the 9/2^(-)level and 17±4 ns for the 5/2^(-)level by using t...Two low-lying isomeric states in 169Ta have been identified via ^(159)Tb(l6O,6nγ)^(169)Ta reaction.Their half-lives are measured to be 28±5ns for the 9/2^(-)level and 17±4 ns for the 5/2^(-)level by using the delayedγ-γcoincidence method.These two isomeric states are considered to be the bandheads with 9/2-[514]and 1/2-[541]configurations,respectively.Possible neutron quasiparticle configuration for the ground state of ^(169)W is discussed.展开更多
The nuclide ^(129)Ce was produced by a(^(16)O,4n)reaction on an enriched ^(117)Sn target.Reaction products were transported to a shielded location by using a helium-jet tape transport system.An activity of 4.1 min in ...The nuclide ^(129)Ce was produced by a(^(16)O,4n)reaction on an enriched ^(117)Sn target.Reaction products were transported to a shielded location by using a helium-jet tape transport system.An activity of 4.1 min in chemically separated cerium sample was identified as ^(129)Ce.Based on x-γ-t andγ-γ-t coincidence measurements,the(EC+β+)decay scheme of ^(129)Ce was proposed,and takes accounts of 50 observedγ-lines.展开更多
High spin states of the odd-odd ^(162)Lu nucleus have been studied via ^(147)Sm(^(19)F,4nγ)reaction at 95MeV beam energy.Level scheme for yrast band based on π[h_(11/2)]v[i_(13/2)]quasiparticle configuration was est...High spin states of the odd-odd ^(162)Lu nucleus have been studied via ^(147)Sm(^(19)F,4nγ)reaction at 95MeV beam energy.Level scheme for yrast band based on π[h_(11/2)]v[i_(13/2)]quasiparticle configuration was established up to I^(π)-(23^(-))for the first time.This band shows the signature inversion in energy before backbending generally appeared in this mass region.It is stressed that the signature splitting in 162Lu is larger than that in 160 Tm nucleus.展开更多
The high-spin states in ^(197)Bi have been studied with the ^(187)Re(^(16)O,6n)reaction at ^(16)O energies from 85 to 105MeV.In-beam measurements of γ-ray excitation functions,γ-γ-t coincidences and γ-ray angular ...The high-spin states in ^(197)Bi have been studied with the ^(187)Re(^(16)O,6n)reaction at ^(16)O energies from 85 to 105MeV.In-beam measurements of γ-ray excitation functions,γ-γ-t coincidences and γ-ray angular distributions were carried out with six BGO(AC)HPGe detectors and one intrinsic Ge planar detector.Eleven new tram sitions and three new isomers were observed,and a level scheme for ^(197)Bi was established.Some differences between the present work and the previous results were found.展开更多
High spin states in neutron-deficient ^(117)Xe have been studied by using in-beamγspectroscopy method.A new positive-parity rotational band has been identified.It decays into the yrast vh_(11/2 )band via five electri...High spin states in neutron-deficient ^(117)Xe have been studied by using in-beamγspectroscopy method.A new positive-parity rotational band has been identified.It decays into the yrast vh_(11/2 )band via five electric dipole transitions.The magnitudes of these E1 transitions are extracted and they are much enhanced compared to the normal E1 transitions.This is taken as an evidence for octupole correlations in ^(117)Xe.展开更多
High-spin states in ^(198)Bi were populated via the ^(187)Re(^(16)O,5n)reaction.A partial level scheme for ^(198)Bi was established for the first time,including a 15^(+)high-spin isomeric state with a measured half-li...High-spin states in ^(198)Bi were populated via the ^(187)Re(^(16)O,5n)reaction.A partial level scheme for ^(198)Bi was established for the first time,including a 15^(+)high-spin isomeric state with a measured half-life of 8.0±3.6ns.By comparing the level structure of ^(198)Bi with that of the even-even core ^(198)Pb,the configuration v(i_(13/2))^(-2) v(P_(3/2))^(-1)π(h_(9/2))^(1) was ascribed to this isomeric state.展开更多
The β-delayed proton decay of 147Er is studied experimentally using the 58 Ni＋92Mo reaction at a beam energy of 383 MeV. Based on a He-jet apparatus coupled with a tape transport system, the β-delayed proton radioa...The β-delayed proton decay of 147Er is studied experimentally using the 58 Ni＋92Mo reaction at a beam energy of 383 MeV. Based on a He-jet apparatus coupled with a tape transport system, the β-delayed proton radioactivities both from the vδl/2 ground state and the vh11/2 isomer in 147 Er are identified by proton-7 coincidence measurements. By analyzing the time distribution of the 4＋ → 2＋-γ transition in the grand-daughter nucleus 146Dy, a half-life of 1.6 ± 0.2s is determined for the Vh11/2 isomer in 147 Er. The half-life for the ground state of 147Er is estimated to be 3.2±1.2 s.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 10825522 and 11175217the Chinese Academy of Sciences。
文摘Gamma rays with energies between 80keV and 1500keV produced by 133Ba and 152Eu standard sources are measured with the clover detector.Relative efficiencies and add-back factors are determined in both crystals and full clover modes.The add-back characteristics have been calculated using Monte-Carlo simulation code Geant4.The simulation and measurements agree very well.
基金Supported by the National Natural Science Foundation of China under Grant No.19975057,and the Chinese Academy of Sciences。
文摘The (EC+β^(+)) decay of ^(128)Ce was reinvestigated in the^(116)Sn (l6O, 4n) reaction by using a helium-jet tape transport system. The decay γ rays of ^(128)Ce were unambiguously described from those of ^(129)Ce after taking the comparing experiments of ^(16)O+^(116)Sn and ^(16)O+^(117)Sn. Based on x-γ and γ-γ coincidence measurements, a detailed (EC+β^(+)) decay scheme of ^(128)Ce has been proposed which modifies the previous one, and takes accounts of 100 observed γ-lines.
基金Supported by the Chinese Academy of Sciences and the National Natural Science Foundation of Chins under Grant Nos.19675052,19635030 and 19805011.
文摘High-spin states of^(119)Xe have been investigated by in-beam γ-ray spectroscopy via the reaction of ^(16)O bombarding a ^(106)Cd target at beam energies of 67-80MeV. No enhanced E1 transition was observed, the non-existence of octupole correlations in ^(119) Xe.
基金Supported by the State Education Committee of Chinathe National Natural Science Foundation of China under Grant No.19605008.
文摘Two low-lying isomeric states in 169Ta have been identified via ^(159)Tb(l6O,6nγ)^(169)Ta reaction.Their half-lives are measured to be 28±5ns for the 9/2^(-)level and 17±4 ns for the 5/2^(-)level by using the delayedγ-γcoincidence method.These two isomeric states are considered to be the bandheads with 9/2-[514]and 1/2-[541]configurations,respectively.Possible neutron quasiparticle configuration for the ground state of ^(169)W is discussed.
基金Supported by the Chinese Academy of Sciencesthe National Natural Science Foundation of China under Grant No.19475055.
文摘The nuclide ^(129)Ce was produced by a(^(16)O,4n)reaction on an enriched ^(117)Sn target.Reaction products were transported to a shielded location by using a helium-jet tape transport system.An activity of 4.1 min in chemically separated cerium sample was identified as ^(129)Ce.Based on x-γ-t andγ-γ-t coincidence measurements,the(EC+β+)decay scheme of ^(129)Ce was proposed,and takes accounts of 50 observedγ-lines.
基金Supported by the Research Fund of National Post-Doctor Committeethe China National Education Committeethe Chinese Academy of Sciences.
文摘High spin states of the odd-odd ^(162)Lu nucleus have been studied via ^(147)Sm(^(19)F,4nγ)reaction at 95MeV beam energy.Level scheme for yrast band based on π[h_(11/2)]v[i_(13/2)]quasiparticle configuration was established up to I^(π)-(23^(-))for the first time.This band shows the signature inversion in energy before backbending generally appeared in this mass region.It is stressed that the signature splitting in 162Lu is larger than that in 160 Tm nucleus.
文摘The high-spin states in ^(197)Bi have been studied with the ^(187)Re(^(16)O,6n)reaction at ^(16)O energies from 85 to 105MeV.In-beam measurements of γ-ray excitation functions,γ-γ-t coincidences and γ-ray angular distributions were carried out with six BGO(AC)HPGe detectors and one intrinsic Ge planar detector.Eleven new tram sitions and three new isomers were observed,and a level scheme for ^(197)Bi was established.Some differences between the present work and the previous results were found.
基金Supported by the National Natural Science Foundation of China。
文摘High spin states in neutron-deficient ^(117)Xe have been studied by using in-beamγspectroscopy method.A new positive-parity rotational band has been identified.It decays into the yrast vh_(11/2 )band via five electric dipole transitions.The magnitudes of these E1 transitions are extracted and they are much enhanced compared to the normal E1 transitions.This is taken as an evidence for octupole correlations in ^(117)Xe.
基金Supported by the National Natural Science Foundation of China。
文摘High-spin states in ^(198)Bi were populated via the ^(187)Re(^(16)O,5n)reaction.A partial level scheme for ^(198)Bi was established for the first time,including a 15^(+)high-spin isomeric state with a measured half-life of 8.0±3.6ns.By comparing the level structure of ^(198)Bi with that of the even-even core ^(198)Pb,the configuration v(i_(13/2))^(-2) v(P_(3/2))^(-1)π(h_(9/2))^(1) was ascribed to this isomeric state.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10825522, 10735010 and 10575120, and the National Basic Research Program of China under Grant No 2007CB815001.
文摘The β-delayed proton decay of 147Er is studied experimentally using the 58 Ni＋92Mo reaction at a beam energy of 383 MeV. Based on a He-jet apparatus coupled with a tape transport system, the β-delayed proton radioactivities both from the vδl/2 ground state and the vh11/2 isomer in 147 Er are identified by proton-7 coincidence measurements. By analyzing the time distribution of the 4＋ → 2＋-γ transition in the grand-daughter nucleus 146Dy, a half-life of 1.6 ± 0.2s is determined for the Vh11/2 isomer in 147 Er. The half-life for the ground state of 147Er is estimated to be 3.2±1.2 s.
