The g-factors of the rotational states along the positive parity yrast band in even-even nuclei ^(84)Zr were measured up to a spin I=16^(+)by a transient magnetic field-ion implanted perturbed angular distribution met...The g-factors of the rotational states along the positive parity yrast band in even-even nuclei ^(84)Zr were measured up to a spin I=16^(+)by a transient magnetic field-ion implanted perturbed angular distribution method and calculated by a cranking shell model.A peak structure of the g-factors has been observed for the first time.The measured g-factors confirm the mixed configuration of proton and neutron alignments.展开更多
High spin states of the odd-proton nucleus ^(167)Lu have been studied via ^(152)Sm(^(19)F,4n)^(167)Lu reaction at 87MeV beam energy.A weakly populated new rotationa1 band has been observed and assigned as i13/2 proton...High spin states of the odd-proton nucleus ^(167)Lu have been studied via ^(152)Sm(^(19)F,4n)^(167)Lu reaction at 87MeV beam energy.A weakly populated new rotationa1 band has been observed and assigned as i13/2 proton 1/2^(+)[660] band.This new band and the 1/2^(+)[660] band in ^(171)Ta from the early work are classified as superdeformed bands with triaxiality.展开更多
High spin states of the odd-odd nucleus 92Nb are investigated using the S2Se （14N, 4n）92Nb reaction at a beam energy of 54MeV. The level scheme of the 92Nb was extended up to Jπ=（16＋） at about 7.3 MeV and Jπ=（...High spin states of the odd-odd nucleus 92Nb are investigated using the S2Se （14N, 4n）92Nb reaction at a beam energy of 54MeV. The level scheme of the 92Nb was extended up to Jπ=（16＋） at about 7.3 MeV and Jπ=（21-） at about 9.7MeV. According to systematic analyses and a comparison with the neighboring nucleus, the higher spin states could be interpreted by the multi-particle excitations in the π（fs/2,P3/2,p1/2,gg/2）@v（p1/x,gg/2,d5/2, g7/2） configuration space.展开更多
Level structures of 113 In are studied through the fusion-evaporation reaction 110 Pd(7 Li,4n)113In at a beam energy of 50 Me V.Two new bands are established for the first time.Here the ΔI =2 band based on proton exc...Level structures of 113 In are studied through the fusion-evaporation reaction 110 Pd(7 Li,4n)113In at a beam energy of 50 Me V.Two new bands are established for the first time.Here the ΔI =2 band based on proton excitation is assigned to the πg-29/2 (0)υh211/2d5/2 configuration.In addition,the backbending associated with the additional aligned h11/2 neutron pair is found in the negative parity yrast band.The experimental results are compared with self-consistent tilted axis cranking relativistic mean field calculations.Several decay paths of theπ h11/2intruder band are established,by which the level energies and spins of the πh11/2 intruder band are determined.The bandcrossing delay of the πh11/2 intruder bands around the Z =50 shell and the dynamic moment of inertia of the πg-19/2 (0) υh^(2)_(11/2) bands in 113,115,117,119 In are studied systematically.展开更多
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
Excited states of the odd-odd nucleus 122I are investigated via the fusion-evaporation reaction 116Cd(11B,5n)at a beam energy of 68 MeV.The two most strongly populated bands in 122I are observed up to excitation energ...Excited states of the odd-odd nucleus 122I are investigated via the fusion-evaporation reaction 116Cd(11B,5n)at a beam energy of 68 MeV.The two most strongly populated bands in 122I are observed up to excitation energies around 10.5 MeV.Their possible configurations at lower spins are assigned toπh_(11/2)■νh_(11/2) andπh_(11/2)■νd_(5/2) based on the observed population,B(M1)/B(E2)values,alignments and signature splitting.E1 transitions are observed connecting theπh_(11/2)■νd_(5/2) band to theπh_(11/2)■νh_(11/2) band,which may be evidence of octupole collectivity.Band terminations caused by the full alignment of the valence nucleons outside the 114Sn core are observed in both bands.展开更多
High spin states in ^(90)Mo have been populated through the ^(59)Co (^(35)Cl,2p2n) 90Mo reaction at beam energy of 116 MeV. Level lifetimes of the positive-parity decay sequence are measured by using the Doppler shift...High spin states in ^(90)Mo have been populated through the ^(59)Co (^(35)Cl,2p2n) 90Mo reaction at beam energy of 116 MeV. Level lifetimes of the positive-parity decay sequence are measured by using the Doppler shift attenuation method. It is observed that the M1 transition strengths show a substantial enhancement at high spin. This behaviour may be related to occupation of high Ω orbitals by a pair of g9/2 protons. A deformed shape with oblate is suggested above the 13^(+) state.展开更多
High spin states in ^(137) Ce have been studied by using the heavy-ion induced reaction ^(124)Sn(^(18) O, 5n) carried out at China Institute of Atomic Energy. Partial level scheme with spin up to (43/2^(-)), including...High spin states in ^(137) Ce have been studied by using the heavy-ion induced reaction ^(124)Sn(^(18) O, 5n) carried out at China Institute of Atomic Energy. Partial level scheme with spin up to (43/2^(-)), including a high spin collective rotational band observed for the first time, has been established. The collective band shows the properties similar to those oblate bands with γ ~-60° in neighboring nuclei and probably originates from the five quasi-particle configuration νs_(1/2)■ [vh_(11/2)]^(2)π9_(7/2)■ πh_(11/2). The characteristics of this oblate band have been discussed.展开更多
By means of beam chopping and γ-γ coincidence technique,the in-beam γ-rays and decay γ-rays of the 15OMeV^(40)Ca+^(58)Ni reaction products have been measured.The four strongest transition γ-rays of ^(92)Rh have b...By means of beam chopping and γ-γ coincidence technique,the in-beam γ-rays and decay γ-rays of the 15OMeV^(40)Ca+^(58)Ni reaction products have been measured.The four strongest transition γ-rays of ^(92)Rh have been clearly observed.The decay γ-rays of ^(92)Rh have been identified for the first time.The spin and parity of 6^(+) are tentatively assigned to the ground state of ^(92)Rh.Part of the decay scheme of 92Rh is proposed.展开更多
High-spin states in^(84)Rb have been studied by using the^(70)Zn(^(18)O,p3n)^(84)Rb reaction at a beam energy of 75 MeV.Theγ-γcoincidence,excitation function and ratios for directional correlation of oriented states...High-spin states in^(84)Rb have been studied by using the^(70)Zn(^(18)O,p3n)^(84)Rb reaction at a beam energy of 75 MeV.Theγ-γcoincidence,excitation function and ratios for directional correlation of oriented states were performed.A new level scheme was established in which the positive and negative parity bands have been extended up to 17^(+)and 17^(-)with excitation energy about 7MeV.The signature splitting and signature inversion of the positive parity yrast bands were observed and are discussed.展开更多
Structure of high spin states in ^(87)Zr was studied through the reaction ^(59)Co(^(32)S,3pn)^(87)Zr at a beam energy of 118 MeV using in-beam γ-ray spectroscopic method.Measurement of γ-γ coincidence was performed...Structure of high spin states in ^(87)Zr was studied through the reaction ^(59)Co(^(32)S,3pn)^(87)Zr at a beam energy of 118 MeV using in-beam γ-ray spectroscopic method.Measurement of γ-γ coincidence was performed,and directional correlation orientation ratios of someγrays were determined.The level scheme of ^(87)Zr was established up to spin(37/2^(+))and(43/2^(-)).Many previously unknown states have been observed.Comparison with neighboring isotones indicates that the effect of neutron on nuclear structure property is predominant compared to proton,and there is a tendency of reduction in band crossing frequency with increasing proton number.展开更多
High spin states in 138Ce have been investigated following heavy-ion induced reactions carried out at the China Institute of Atomic Energy,Beijing.Two collective rotational bands were established for the first time.Th...High spin states in 138Ce have been investigated following heavy-ion induced reactions carried out at the China Institute of Atomic Energy,Beijing.Two collective rotational bands were established for the first time.These two bands show oblate deformation withγ=-60°and probably originate from the four quasiparticle configurationsπg7/2πh11/2Uvh11/2 vd3/2 andπg7/2Uπh11/2[vh11/2]2,respectively.These oblate bands exhibit strong M1 transitions,no signature splitting and different moments of inertia from those of prolate bands.展开更多
The factors that influence underwater vehicle sonar self-noise are analyzed, and genetic algorithms and a back propagation (BP) neural network are combined to predict underwater vehicle sonar self-noise. The experimen...The factors that influence underwater vehicle sonar self-noise are analyzed, and genetic algorithms and a back propagation (BP) neural network are combined to predict underwater vehicle sonar self-noise. The experimental results demonstrate that underwater vehicle sonar self-noise can be predicted accurately by a GA-BP neural network that is based on actual underwater vehicle sonar data.展开更多
High-spin states in^(189)Pt are populated through the heavy-ion fusion-evaporation reaction^(176)Yb(18O,5n)^(189)Pt at 87 MeV beam energy.An array consisting of 13 HPGe detectors is used in conjunction with the plunge...High-spin states in^(189)Pt are populated through the heavy-ion fusion-evaporation reaction^(176)Yb(18O,5n)^(189)Pt at 87 MeV beam energy.An array consisting of 13 HPGe detectors is used in conjunction with the plunger device in CIAE.The lifetimes of two levels in the yrast band are determined by using the recoil distance Doppler shift method.The transition quadrupole moments Qt are extracted.The results show that the 17+/2 state has a much larger Qt value than that of the ground state,whereas the value deceases quickly with spin increasing.This may contribute to the shape driving effect of the quasi-neutron from the i_(13/2)orbital.展开更多
Excited states in^(120)I are investigated utilizing in-beam gamma-ray spectroscopy following the^(114)Cd(^(11)B,5n)reaction at 70 MeV bombarding energy.A level scheme is constructed with states up to 9 MeV.The levels ...Excited states in^(120)I are investigated utilizing in-beam gamma-ray spectroscopy following the^(114)Cd(^(11)B,5n)reaction at 70 MeV bombarding energy.A level scheme is constructed with states up to 9 MeV.The levels are classified into several bands and their possible configurations at low spins are discussed briefly.Based on the linking transitions between different bands at higher spins,the excitation energy of the previously reported T1/2=53 min isomer is ascertained to be 72 keV.Evidence showing the existence of an isomer at an excitation energy of 6.4 MeV is presented.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.19775070.
文摘The g-factors of the rotational states along the positive parity yrast band in even-even nuclei ^(84)Zr were measured up to a spin I=16^(+)by a transient magnetic field-ion implanted perturbed angular distribution method and calculated by a cranking shell model.A peak structure of the g-factors has been observed for the first time.The measured g-factors confirm the mixed configuration of proton and neutron alignments.
基金Supported by the National Natural Science Foundation of Chinathe Science Foundation of Nuclear Industry of China.
文摘High spin states of the odd-proton nucleus ^(167)Lu have been studied via ^(152)Sm(^(19)F,4n)^(167)Lu reaction at 87MeV beam energy.A weakly populated new rotationa1 band has been observed and assigned as i13/2 proton 1/2^(+)[660] band.This new band and the 1/2^(+)[660] band in ^(171)Ta from the early work are classified as superdeformed bands with triaxiality.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11075064, 10927507, 11075214, 10675171, 11175259.
文摘High spin states of the odd-odd nucleus 92Nb are investigated using the S2Se （14N, 4n）92Nb reaction at a beam energy of 54MeV. The level scheme of the 92Nb was extended up to Jπ=（16＋） at about 7.3 MeV and Jπ=（21-） at about 9.7MeV. According to systematic analyses and a comparison with the neighboring nucleus, the higher spin states could be interpreted by the multi-particle excitations in the π（fs/2,P3/2,p1/2,gg/2）@v（p1/x,gg/2,d5/2, g7/2） configuration space.
基金Supported by the National Basic Research Program of China under Grant No 2007CB815005the National Natural Science Foundation of China under Grant No 11075064the Specialized Research Fund for the Doctoral Programme of Higher Education of China under Grant No 20050183008.
文摘Level structures of 113 In are studied through the fusion-evaporation reaction 110 Pd(7 Li,4n)113In at a beam energy of 50 Me V.Two new bands are established for the first time.Here the ΔI =2 band based on proton excitation is assigned to the πg-29/2 (0)υh211/2d5/2 configuration.In addition,the backbending associated with the additional aligned h11/2 neutron pair is found in the negative parity yrast band.The experimental results are compared with self-consistent tilted axis cranking relativistic mean field calculations.Several decay paths of theπ h11/2intruder band are established,by which the level energies and spins of the πh11/2 intruder band are determined.The bandcrossing delay of the πh11/2 intruder bands around the Z =50 shell and the dynamic moment of inertia of the πg-19/2 (0) υh^(2)_(11/2) bands in 113,115,117,119 In are studied systematically.
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(10675053)the National Basic Research Programme of China(2007CB815005)RFDP(20060183048)。
文摘Excited states of the odd-odd nucleus 122I are investigated via the fusion-evaporation reaction 116Cd(11B,5n)at a beam energy of 68 MeV.The two most strongly populated bands in 122I are observed up to excitation energies around 10.5 MeV.Their possible configurations at lower spins are assigned toπh_(11/2)■νh_(11/2) andπh_(11/2)■νd_(5/2) based on the observed population,B(M1)/B(E2)values,alignments and signature splitting.E1 transitions are observed connecting theπh_(11/2)■νd_(5/2) band to theπh_(11/2)■νh_(11/2) band,which may be evidence of octupole collectivity.Band terminations caused by the full alignment of the valence nucleons outside the 114Sn core are observed in both bands.
基金Supported by the National Natural Science Foundation of China under Grant Nos.19675067 and 19975070.
文摘High spin states in ^(90)Mo have been populated through the ^(59)Co (^(35)Cl,2p2n) 90Mo reaction at beam energy of 116 MeV. Level lifetimes of the positive-parity decay sequence are measured by using the Doppler shift attenuation method. It is observed that the M1 transition strengths show a substantial enhancement at high spin. This behaviour may be related to occupation of high Ω orbitals by a pair of g9/2 protons. A deformed shape with oblate is suggested above the 13^(+) state.
基金Supported by the National Natural Science Foundation of China under Grant No.19775026the Science Foundation for the Nuclear Industry of China under Grant No.Y7192AY509.
文摘High spin states in ^(137) Ce have been studied by using the heavy-ion induced reaction ^(124)Sn(^(18) O, 5n) carried out at China Institute of Atomic Energy. Partial level scheme with spin up to (43/2^(-)), including a high spin collective rotational band observed for the first time, has been established. The collective band shows the properties similar to those oblate bands with γ ~-60° in neighboring nuclei and probably originates from the five quasi-particle configuration νs_(1/2)■ [vh_(11/2)]^(2)π9_(7/2)■ πh_(11/2). The characteristics of this oblate band have been discussed.
基金Supported by the China National Nuclear Corporation under Grant No.J95A01031.
文摘By means of beam chopping and γ-γ coincidence technique,the in-beam γ-rays and decay γ-rays of the 15OMeV^(40)Ca+^(58)Ni reaction products have been measured.The four strongest transition γ-rays of ^(92)Rh have been clearly observed.The decay γ-rays of ^(92)Rh have been identified for the first time.The spin and parity of 6^(+) are tentatively assigned to the ground state of ^(92)Rh.Part of the decay scheme of 92Rh is proposed.
基金Supported by the National Natural Science Foundation of China under Grant No.19635030the Science Foundation of the Nuclear Industry of China.
文摘High-spin states in^(84)Rb have been studied by using the^(70)Zn(^(18)O,p3n)^(84)Rb reaction at a beam energy of 75 MeV.Theγ-γcoincidence,excitation function and ratios for directional correlation of oriented states were performed.A new level scheme was established in which the positive and negative parity bands have been extended up to 17^(+)and 17^(-)with excitation energy about 7MeV.The signature splitting and signature inversion of the positive parity yrast bands were observed and are discussed.
基金Supported by the National Natural Science Foundation of China under Grant No.19675067.
文摘Structure of high spin states in ^(87)Zr was studied through the reaction ^(59)Co(^(32)S,3pn)^(87)Zr at a beam energy of 118 MeV using in-beam γ-ray spectroscopic method.Measurement of γ-γ coincidence was performed,and directional correlation orientation ratios of someγrays were determined.The level scheme of ^(87)Zr was established up to spin(37/2^(+))and(43/2^(-)).Many previously unknown states have been observed.Comparison with neighboring isotones indicates that the effect of neutron on nuclear structure property is predominant compared to proton,and there is a tendency of reduction in band crossing frequency with increasing proton number.
基金the National Natural Science Foundation of China under Grant No.19775026the Science Foundation for the Nuclear Industry of China under Grant No.Y7192AY509.
文摘High spin states in 138Ce have been investigated following heavy-ion induced reactions carried out at the China Institute of Atomic Energy,Beijing.Two collective rotational bands were established for the first time.These two bands show oblate deformation withγ=-60°and probably originate from the four quasiparticle configurationsπg7/2πh11/2Uvh11/2 vd3/2 andπg7/2Uπh11/2[vh11/2]2,respectively.These oblate bands exhibit strong M1 transitions,no signature splitting and different moments of inertia from those of prolate bands.
文摘The factors that influence underwater vehicle sonar self-noise are analyzed, and genetic algorithms and a back propagation (BP) neural network are combined to predict underwater vehicle sonar self-noise. The experimental results demonstrate that underwater vehicle sonar self-noise can be predicted accurately by a GA-BP neural network that is based on actual underwater vehicle sonar data.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11175259,11075214 and 10927507.
文摘High-spin states in^(189)Pt are populated through the heavy-ion fusion-evaporation reaction^(176)Yb(18O,5n)^(189)Pt at 87 MeV beam energy.An array consisting of 13 HPGe detectors is used in conjunction with the plunger device in CIAE.The lifetimes of two levels in the yrast band are determined by using the recoil distance Doppler shift method.The transition quadrupole moments Qt are extracted.The results show that the 17+/2 state has a much larger Qt value than that of the ground state,whereas the value deceases quickly with spin increasing.This may contribute to the shape driving effect of the quasi-neutron from the i_(13/2)orbital.
基金Supported by the National Natural Science Foundation of China under Grant No 10675053the National Basic Research Program of China under Grant No 2007CB815005the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20120061110008.
文摘Excited states in^(120)I are investigated utilizing in-beam gamma-ray spectroscopy following the^(114)Cd(^(11)B,5n)reaction at 70 MeV bombarding energy.A level scheme is constructed with states up to 9 MeV.The levels are classified into several bands and their possible configurations at low spins are discussed briefly.Based on the linking transitions between different bands at higher spins,the excitation energy of the previously reported T1/2=53 min isomer is ascertained to be 72 keV.Evidence showing the existence of an isomer at an excitation energy of 6.4 MeV is presented.
