Theα-decay of neutron-deficient heavy nuclei far from stability is an indispensable spectroscopic tool to study their low-energy structure.220Pa,a trans-lead isotope near the shell closure N=126,its decay propertie...Theα-decay of neutron-deficient heavy nuclei far from stability is an indispensable spectroscopic tool to study their low-energy structure.220Pa,a trans-lead isotope near the shell closure N=126,its decay properties are still not well established,though it was studied in twoα-decay experiments 30 years ago[1,2].Recently,we applied successfully the modern digital pulse processing(DPP)technique[3,4]to the decay spectroscopy in the Z≥91 and N=128~131 region[5]and the decay chain of 220Pa was established at the first time.展开更多
Taking advantage of the largeγ-detector array Gammasphere and the recoil mass separator FMA,highspin states in 117Ba were investigated through the recoil-β-delayed proton decay tagging technique via the heavy-ion in...Taking advantage of the largeγ-detector array Gammasphere and the recoil mass separator FMA,highspin states in 117Ba were investigated through the recoil-β-delayed proton decay tagging technique via the heavy-ion induced fusion-evaporation reaction 64Zn(58Ni,2p3n)117Ba,at a beam energy of 305 MeV.Promptγrays belonging to 117Ba have been identified furthermore,a rotational band has been identified for the first time and presented as band A in Fig.1.展开更多
Isotope 223U synthesized and identified[1;2].αenergy of 8 780(40)keV and a half-life of 55(10)μs.Theαenergy was calculated by subtracting knownαenergy of 219Th from measured decay sum energy of 223U and its daught...Isotope 223U synthesized and identified[1;2].αenergy of 8 780(40)keV and a half-life of 55(10)μs.Theαenergy was calculated by subtracting knownαenergy of 219Th from measured decay sum energy of 223U and its daughter 219Th.Based on the advanced digital pulse processing technique,a new measurement forα-particle energy and half-life of 223U was performed at the gas-filled recoil separator,Spectrometer for Heavy Atoms and Nuclear Structure(SHANS).The isotope 223U was produced in the fusion-evaporation reaction 187Re(40Ar,p3n)223U.展开更多
The Z=56 barium nuclei represent one of the best example of an isotopic chain to explore the evolution of quadrupole deformation as the neutron number decreases. The neutron-deficient barium isotopes with mass number ...The Z=56 barium nuclei represent one of the best example of an isotopic chain to explore the evolution of quadrupole deformation as the neutron number decreases. The neutron-deficient barium isotopes with mass number A ranging from 120 to 130 could be easily produced by the heavy-ion fusionevaporation reactions, and thus have been well studied in ray spectroscopy experiments.展开更多
Neutron-de cient nuclei around mid-shell at N-104 in the lead region provide many cases of shape coexistence and shape isomers^([1,2]).In order to study shape coexistence in this region,prompt and delayed-ray spectros...Neutron-de cient nuclei around mid-shell at N-104 in the lead region provide many cases of shape coexistence and shape isomers^([1,2]).In order to study shape coexistence in this region,prompt and delayed-ray spectroscopy of the^(187)Pb,^(183)Hg,^(188)Bi and^(188)Po nuclei produced by the fusion-evaporation reaction^(50)Cr+^(142)Nd→192Po^(*)has been performed at the Argonne Gas-Filled Analyzer.展开更多
Alpha decay,as a pervasive decay mode of unstable heavy nuclei,plays a crucial role in the identification of new superheavy elements and investigation on nuclear structure of exotic nuclei near the proton drip line.
Digital decay spectroscopy of actinide isotopes at the gas lled separator SHANS Deacy spectroscopy of nuclei with Z>90 were performed using the 187Re+40Ar reaction with isotopically enriched 187Re targets.The 40Ar ...Digital decay spectroscopy of actinide isotopes at the gas lled separator SHANS Deacy spectroscopy of nuclei with Z>90 were performed using the 187Re+40Ar reaction with isotopically enriched 187Re targets.The 40Ar beam was accelerated to 188 MeV by the Sector-Focusing Cyclotron(SFC)of the Heavy Ion Research Facility in Lanzhou(HIRFL).The beam intensity on target,monitored via Faraday Cups upstream and downstream of the target chamber,was around 320 pnA on average during the entire experiment of 110 h.展开更多
Digital decay spectroscopy of actinide isotopes at the gas lled separator SHANS Deacy spectroscopy of nuclei with Z>90 were performed using the ^(187)Re+^(40)Ar reaction with isotopically enriched 187Re targets.The...Digital decay spectroscopy of actinide isotopes at the gas lled separator SHANS Deacy spectroscopy of nuclei with Z>90 were performed using the ^(187)Re+^(40)Ar reaction with isotopically enriched 187Re targets.The 40Ar beam was accelerated to 188 MeV by the Sector-Focusing Cyclotron(SFC)of the Heavy Ion Research Facility in Lanzhou(HIRFL).The beam intensity on target,monitored via Faraday Cups upstream and downstream of the target chamber,was around 320 pnA in average during the entire experiment of 110 h.展开更多
The nuclear reflection asymmetry is attributed to octupole correlation,i:e:the coupling between single-particle orbits with opposite parities andΔl/Δj/3 near the Fermi surface.The strongest correlations tend to occu...The nuclear reflection asymmetry is attributed to octupole correlation,i:e:the coupling between single-particle orbits with opposite parities andΔl/Δj/3 near the Fermi surface.The strongest correlations tend to occur just above closed shells,namely at particle(proton or neutron)numbers 34(g9/2■p3/2 coupling),56(h11/2■d5/2 coupling),88(i13/2■f7/2 coupling)and 134(j15/2■g9/2 coupling).An overview of the experimental and theoretical evidence for octupole correlations is given in Ref.[1].展开更多
Digital decay spectroscopy of actinide isotopes at the gas filled separator SHANS All over the chart of nuclides,the region to the“north-east”of 208Pb,with Z≥84 and N=128~130,hosts the shortest-livedαradioactiviti...Digital decay spectroscopy of actinide isotopes at the gas filled separator SHANS All over the chart of nuclides,the region to the“north-east”of 208Pb,with Z≥84 and N=128~130,hosts the shortest-livedαradioactivities,with half-lives in the range of nanoseconds to microseconds.Synthesis and detection of neutron-deficient isotopes above thorium in this region are challenging due to their low production cross sections and short half-lives.展开更多
文摘Theα-decay of neutron-deficient heavy nuclei far from stability is an indispensable spectroscopic tool to study their low-energy structure.220Pa,a trans-lead isotope near the shell closure N=126,its decay properties are still not well established,though it was studied in twoα-decay experiments 30 years ago[1,2].Recently,we applied successfully the modern digital pulse processing(DPP)technique[3,4]to the decay spectroscopy in the Z≥91 and N=128~131 region[5]and the decay chain of 220Pa was established at the first time.
基金“100 Person Project”of Chinese Academy of Sciences and National Natural Science Foundation of China(11405224 11675225,U1632144,11635003).
文摘Taking advantage of the largeγ-detector array Gammasphere and the recoil mass separator FMA,highspin states in 117Ba were investigated through the recoil-β-delayed proton decay tagging technique via the heavy-ion induced fusion-evaporation reaction 64Zn(58Ni,2p3n)117Ba,at a beam energy of 305 MeV.Promptγrays belonging to 117Ba have been identified furthermore,a rotational band has been identified for the first time and presented as band A in Fig.1.
文摘Isotope 223U synthesized and identified[1;2].αenergy of 8 780(40)keV and a half-life of 55(10)μs.Theαenergy was calculated by subtracting knownαenergy of 219Th from measured decay sum energy of 223U and its daughter 219Th.Based on the advanced digital pulse processing technique,a new measurement forα-particle energy and half-life of 223U was performed at the gas-filled recoil separator,Spectrometer for Heavy Atoms and Nuclear Structure(SHANS).The isotope 223U was produced in the fusion-evaporation reaction 187Re(40Ar,p3n)223U.
基金“One Hundred Talents Program” of Chinese Academy of Sciences and National Natural Science Foundation of China(11405224)
文摘The Z=56 barium nuclei represent one of the best example of an isotopic chain to explore the evolution of quadrupole deformation as the neutron number decreases. The neutron-deficient barium isotopes with mass number A ranging from 120 to 130 could be easily produced by the heavy-ion fusionevaporation reactions, and thus have been well studied in ray spectroscopy experiments.
基金Strategic Priority Research Program of Chinese Academy of Sciences(XDB34000000)National Key R&D Program of China(2018YFA0404402)+2 种基金National Natural Science Foundation of China(12135004,11635003,11961141004,11735017 and U2032138)Chinese Academy of Sciences Presidents International Fellowship Initiative(2020VMA0017)U.S.Department of Energy,Office of Nuclear Physics(DE-AC02-06CH11357,DE-FG02-94ER41041(UNC)and DE-FG02-97ER41033(TUNL))。
文摘Neutron-de cient nuclei around mid-shell at N-104 in the lead region provide many cases of shape coexistence and shape isomers^([1,2]).In order to study shape coexistence in this region,prompt and delayed-ray spectroscopy of the^(187)Pb,^(183)Hg,^(188)Bi and^(188)Po nuclei produced by the fusion-evaporation reaction^(50)Cr+^(142)Nd→192Po^(*)has been performed at the Argonne Gas-Filled Analyzer.
基金National Key R&D Program of China(2018YFA0404402)。
文摘Alpha decay,as a pervasive decay mode of unstable heavy nuclei,plays a crucial role in the identification of new superheavy elements and investigation on nuclear structure of exotic nuclei near the proton drip line.
文摘Digital decay spectroscopy of actinide isotopes at the gas lled separator SHANS Deacy spectroscopy of nuclei with Z>90 were performed using the 187Re+40Ar reaction with isotopically enriched 187Re targets.The 40Ar beam was accelerated to 188 MeV by the Sector-Focusing Cyclotron(SFC)of the Heavy Ion Research Facility in Lanzhou(HIRFL).The beam intensity on target,monitored via Faraday Cups upstream and downstream of the target chamber,was around 320 pnA on average during the entire experiment of 110 h.
文摘Digital decay spectroscopy of actinide isotopes at the gas lled separator SHANS Deacy spectroscopy of nuclei with Z>90 were performed using the ^(187)Re+^(40)Ar reaction with isotopically enriched 187Re targets.The 40Ar beam was accelerated to 188 MeV by the Sector-Focusing Cyclotron(SFC)of the Heavy Ion Research Facility in Lanzhou(HIRFL).The beam intensity on target,monitored via Faraday Cups upstream and downstream of the target chamber,was around 320 pnA in average during the entire experiment of 110 h.
文摘The nuclear reflection asymmetry is attributed to octupole correlation,i:e:the coupling between single-particle orbits with opposite parities andΔl/Δj/3 near the Fermi surface.The strongest correlations tend to occur just above closed shells,namely at particle(proton or neutron)numbers 34(g9/2■p3/2 coupling),56(h11/2■d5/2 coupling),88(i13/2■f7/2 coupling)and 134(j15/2■g9/2 coupling).An overview of the experimental and theoretical evidence for octupole correlations is given in Ref.[1].
文摘Digital decay spectroscopy of actinide isotopes at the gas filled separator SHANS All over the chart of nuclides,the region to the“north-east”of 208Pb,with Z≥84 and N=128~130,hosts the shortest-livedαradioactivities,with half-lives in the range of nanoseconds to microseconds.Synthesis and detection of neutron-deficient isotopes above thorium in this region are challenging due to their low production cross sections and short half-lives.
