High spin states of the odd-odd nucleus 122^Ⅰ have been investigated via the fusion- evaporation reaction 116^Cd（11^B, 5n） at a beam energy of 68 MeV. The yrast band is extended up to Ⅰ^π= （29＋）. The band term...High spin states of the odd-odd nucleus 122^Ⅰ have been investigated via the fusion- evaporation reaction 116^Cd（11^B, 5n） at a beam energy of 68 MeV. The yrast band is extended up to Ⅰ^π= （29＋）. The band termination at Ⅰ^π= （22^＋） reported in previous studies is confirmed and interpreted as arising from a shape change from collective prolate to noncollective oblate according to Total-Routhian-Surface （TRS） calculations. In addition, the Ⅰ^π=（29^＋） state is assigned to the [πh^11/2 （πg7/2）^2]23/2- [（vhll/2）^3 （vd5/2）^2]35/2- configuration corresponding to the full alignment of all valance nucleons outside the semi-closed shell.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^(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
通过熔合蒸发反应^(181)Ta(^(16)O,5n)^(192)Tl,在入射束流为97 Me V能量下,布居^(192)Tl的高自旋态,更新了^(192)Tl的能级纲图。共增加8条新能级,尝试性地指定了能级自旋,将负宇称晕带的能级推高到23-。讨论了^(192)Tl与相邻同位素奇奇...通过熔合蒸发反应^(181)Ta(^(16)O,5n)^(192)Tl,在入射束流为97 Me V能量下,布居^(192)Tl的高自旋态,更新了^(192)Tl的能级纲图。共增加8条新能级,尝试性地指定了能级自旋,将负宇称晕带的能级推高到23-。讨论了^(192)Tl与相邻同位素奇奇核^(194,196,198)Tl负宇称晕带的旋称劈裂与反转现象,发现随着中子数增加,^(196,198)Tl在高自旋处出现了旋称反转,其原因可能是由于中子质子相互作用与科里奥利力相互竞争所致。展开更多
The recoil distance Doppler shift method has been widely used in the study of nuclear structure to determine the level lifetime and absolute transition probabilities.A capacitance servo control plunger based on this m...The recoil distance Doppler shift method has been widely used in the study of nuclear structure to determine the level lifetime and absolute transition probabilities.A capacitance servo control plunger based on this method has been successfully developed by the Nuclear Structure Group of the China Institute of Atomic Energy.Three microscopes were employed to check the parallelism and can therefore guarantee a delicate measurement of the distance between the target and the stopper.This new plunger made a successful performance in the test experiment and the measured lifetime of the 2~＋→0~＋ transition in ^（78）Kr is in agreement with the previous value.展开更多
^186Pt was tested in the framework of IBM-1 and the X（3） model. The results show that ^186Pt is located close to the shape phase transition point, but the B（E2） values little agree with the X（3） model. The shape...^186Pt was tested in the framework of IBM-1 and the X（3） model. The results show that ^186Pt is located close to the shape phase transition point, but the B（E2） values little agree with the X（3） model. The shape evolution in the yrast states of186Pt is also discussed in detail. TRS calculation exhibits a flat bottomed potential at low spin states, but a relatively deep minimum at high spin states. It suggests that a shape evolution from vibrational mode to rotational mode happens in ^186Pt. The result is in agreement with the E-GOS calculation.展开更多
A mini-orange spectrometer used for in-beam measurements of internal conversion electrons, consisting of a Si（Li） detector and different sets of Sm05 permanent magnets for filtering and transporting the conversion e...A mini-orange spectrometer used for in-beam measurements of internal conversion electrons, consisting of a Si（Li） detector and different sets of Sm05 permanent magnets for filtering and transporting the conversion electrons to the Si（Li） detector, has been developed at the China Institute of Atomic Energy. The working principles and configuration of the mini-orange spectrometer are described. The performance of the setup is illustrated by measured singles conversion electron spectra using the mini-orange spectrometer.展开更多
High spin states of the odd-A STSr were populated by the fusion-evaporation reaction ^82Se（^9Be,4n） u. br at a beam energy of 46 MeV. Excited levels of SrSr have been extended up to an excitation energy of 7.4 MeV a...High spin states of the odd-A STSr were populated by the fusion-evaporation reaction ^82Se（^9Be,4n） u. br at a beam energy of 46 MeV. Excited levels of SrSr have been extended up to an excitation energy of 7.4 MeV at spin 31/2h. The coupling of a g9/2 neutron hole to the yrast states of the SSSr core can account for the low-lying states in STSr. The structure of the higher spin states is discussed by analogy with those of the neighboring odd-A N=49 isotones and possible configurations are proposed.展开更多
Excited states of^(119)Sn have been studied using an in-beamγ-ray spectroscopic technique following the incomplete fusion of 7 Li on a^(116)Cd target at a beam energy of 42 MeV.A new bandlike structure is proposed to...Excited states of^(119)Sn have been studied using an in-beamγ-ray spectroscopic technique following the incomplete fusion of 7 Li on a^(116)Cd target at a beam energy of 42 MeV.A new bandlike structure is proposed to result from deformed two-particle-two-hole(2p-2h)proton excitations across the Z=50 closed shell based on the systematics of odd-A Sn isotopes and configuration-fixed constrained triaxial relativistic mean-field calculations.This observation extends the boundaries of the deformed 2p-2h collective band to A=119 in Sn isotopes.展开更多
Excited states in the odd-A nucleus 71Ga have been studied via the ^(70)Zn(7Li,a2n)^(71)Ga fusion-evaporation reaction with incident beam energies of 30 and 35 MeV.The level scheme is established up to spin I^(n)=(29/...Excited states in the odd-A nucleus 71Ga have been studied via the ^(70)Zn(7Li,a2n)^(71)Ga fusion-evaporation reaction with incident beam energies of 30 and 35 MeV.The level scheme is established up to spin I^(n)=(29/2^(+))and an excitation energy-6.6 MeV.A previously known sequence built on the 9/2^(+) state is extended as a novel rotational band originating from the v(8^(2)_(9/2)alignment.Furthermore,a negative-parity sequence Is also reported.The observed energy levels of Ga have been interpreted in the framework of the nuclear shell model(SM).展开更多
The lifetime of the 2^+1 state in ^106Cd populated via the ^94Zr(^16O,4n)^106Cd reaction has been measured with the Recoil Distance Doppler Shift technique in combination with the Differential Decay Curve Method.By su...The lifetime of the 2^+1 state in ^106Cd populated via the ^94Zr(^16O,4n)^106Cd reaction has been measured with the Recoil Distance Doppler Shift technique in combination with the Differential Decay Curve Method.By subtracting the contamination in the data,the mean lifetime of the I^π=2^+1633 keV state was determined as 9.9(12)ps.The B(E2)value calculated in this study is in good agreement with the experimental systematics and was compared to the shell model calculations.展开更多
基金supported by National Natural Science Foundation of China (Nos.10675053,10475033)National Basic Research Program of China(No.2007CB815005)
文摘High spin states of the odd-odd nucleus 122^Ⅰ have been investigated via the fusion- evaporation reaction 116^Cd（11^B, 5n） at a beam energy of 68 MeV. The yrast band is extended up to Ⅰ^π= （29＋）. The band termination at Ⅰ^π= （22^＋） reported in previous studies is confirmed and interpreted as arising from a shape change from collective prolate to noncollective oblate according to Total-Routhian-Surface （TRS） calculations. In addition, the Ⅰ^π=（29^＋） state is assigned to the [πh^11/2 （πg7/2）^2]23/2- [（vhll/2）^3 （vd5/2）^2]35/2- configuration corresponding to the full alignment of all valance nucleons outside the semi-closed shell.
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 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.
文摘通过熔合蒸发反应^(181)Ta(^(16)O,5n)^(192)Tl,在入射束流为97 Me V能量下,布居^(192)Tl的高自旋态,更新了^(192)Tl的能级纲图。共增加8条新能级,尝试性地指定了能级自旋,将负宇称晕带的能级推高到23-。讨论了^(192)Tl与相邻同位素奇奇核^(194,196,198)Tl负宇称晕带的旋称劈裂与反转现象,发现随着中子数增加,^(196,198)Tl在高自旋处出现了旋称反转,其原因可能是由于中子质子相互作用与科里奥利力相互竞争所致。
基金Supported by National Natural Science Foundation of China(10675171,10927507,11075214,11175259)
文摘The recoil distance Doppler shift method has been widely used in the study of nuclear structure to determine the level lifetime and absolute transition probabilities.A capacitance servo control plunger based on this method has been successfully developed by the Nuclear Structure Group of the China Institute of Atomic Energy.Three microscopes were employed to check the parallelism and can therefore guarantee a delicate measurement of the distance between the target and the stopper.This new plunger made a successful performance in the test experiment and the measured lifetime of the 2~＋→0~＋ transition in ^（78）Kr is in agreement with the previous value.
基金Supported by National Natural Science Foundation of China(11175259,11075214,10927507)
文摘^186Pt was tested in the framework of IBM-1 and the X（3） model. The results show that ^186Pt is located close to the shape phase transition point, but the B（E2） values little agree with the X（3） model. The shape evolution in the yrast states of186Pt is also discussed in detail. TRS calculation exhibits a flat bottomed potential at low spin states, but a relatively deep minimum at high spin states. It suggests that a shape evolution from vibrational mode to rotational mode happens in ^186Pt. The result is in agreement with the E-GOS calculation.
基金Supported by National Natural Science Foundation of China(11305269,11375267,11475072,11405274,11205068,11175259)
文摘A mini-orange spectrometer used for in-beam measurements of internal conversion electrons, consisting of a Si（Li） detector and different sets of Sm05 permanent magnets for filtering and transporting the conversion electrons to the Si（Li） detector, has been developed at the China Institute of Atomic Energy. The working principles and configuration of the mini-orange spectrometer are described. The performance of the setup is illustrated by measured singles conversion electron spectra using the mini-orange spectrometer.
基金Supported by National Natural Science Foundation of China(10927507,11075214,10675171,11175259 and 11075064)
文摘High spin states of the odd-A STSr were populated by the fusion-evaporation reaction ^82Se（^9Be,4n） u. br at a beam energy of 46 MeV. Excited levels of SrSr have been extended up to an excitation energy of 7.4 MeV at spin 31/2h. The coupling of a g9/2 neutron hole to the yrast states of the SSSr core can account for the low-lying states in STSr. The structure of the higher spin states is discussed by analogy with those of the neighboring odd-A N=49 isotones and possible configurations are proposed.
基金the Major Program of Natural Science Foundation of Shandong Province(ZR2020ZD30)the National Natural Science Foundation of China(12075137,12075138,11975315,U1867210,U1932209)the Young Scholars Program of Shandong University。
文摘Excited states of^(119)Sn have been studied using an in-beamγ-ray spectroscopic technique following the incomplete fusion of 7 Li on a^(116)Cd target at a beam energy of 42 MeV.A new bandlike structure is proposed to result from deformed two-particle-two-hole(2p-2h)proton excitations across the Z=50 closed shell based on the systematics of odd-A Sn isotopes and configuration-fixed constrained triaxial relativistic mean-field calculations.This observation extends the boundaries of the deformed 2p-2h collective band to A=119 in Sn isotopes.
基金Supported by the National Natural Science Foundation of China(U1932209,11975315,U1867210,11905134)the Leading Innovation Project under Grant(LC192209000701,LC202309000201)+1 种基金the Continuous Basic Scientific Research Project(BJ20002501,WDJC-2019-13)China National Nuclear Corporation(FA18000201)。
文摘Excited states in the odd-A nucleus 71Ga have been studied via the ^(70)Zn(7Li,a2n)^(71)Ga fusion-evaporation reaction with incident beam energies of 30 and 35 MeV.The level scheme is established up to spin I^(n)=(29/2^(+))and an excitation energy-6.6 MeV.A previously known sequence built on the 9/2^(+) state is extended as a novel rotational band originating from the v(8^(2)_(9/2)alignment.Furthermore,a negative-parity sequence Is also reported.The observed energy levels of Ga have been interpreted in the framework of the nuclear shell model(SM).
基金Supported by National Key Research and Development Program of China(2017YFF0106501)National Natural Science Foundation of China(11905134,11975315,U1932209,11575118,11605114)+3 种基金NSFC-CNNC Joint Project for Nuclear Technology Innovation(U1867210)Continuous Basic Scientific Research Project(WDJC-2019-13)Project funded by China Post-doctoral Science Foundation(2019M652999)and National Natural Science Foundation of Guangdong China(2016A030310042)。
文摘The lifetime of the 2^+1 state in ^106Cd populated via the ^94Zr(^16O,4n)^106Cd reaction has been measured with the Recoil Distance Doppler Shift technique in combination with the Differential Decay Curve Method.By subtracting the contamination in the data,the mean lifetime of the I^π=2^+1633 keV state was determined as 9.9(12)ps.The B(E2)value calculated in this study is in good agreement with the experimental systematics and was compared to the shell model calculations.
