We report the results of the experiment on synthesizing 287,288Mc isotopes (Z=115) using the fusionevaporation reaction 243Am(48Ca,4n,3n)287,288Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-...We report the results of the experiment on synthesizing 287,288Mc isotopes (Z=115) using the fusionevaporation reaction 243Am(48Ca,4n,3n)287,288Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-2(SHANS2),a gas-filled recoil separator located at the China Accelerator Facility for Superheavy Elements(CAFE2).In total,20 decay chains are attributed to 288Mc and 1 decay chain is assigned to 287Mc.The measured oa-decay properties of 287,288Mc as well as its descendants are consistent with the known data.No additional decay chains originating from the 2n or 5n reaction channels were detected.The excitation function of the 243Am(48Ca,3n)288Mc reaction was measured at the cross-section level of picobarn,which indicates the promising capability for the study of heavy and superheavy nuclei at the facility.展开更多
Fig.3.(a)α-particle energy spectra,and(b)decay-time distributions on a logarithmic scale for the observed 288Mc and its descendant nuclei.In the panel(a),the red histograms show the observed full-energy events,while ...Fig.3.(a)α-particle energy spectra,and(b)decay-time distributions on a logarithmic scale for the observed 288Mc and its descendant nuclei.In the panel(a),the red histograms show the observed full-energy events,while the corresponding blue histograms show the reconstructed events.The red smooth curves in panel(b)are the expected time distributions according to the corresponding half-lives extracted from this work.展开更多
The new thorium isotope 207Th has been produced in the 5n evaporation channel of the fusion reaction 36Ar+176Hf.The 197-199 MeV 36Ar11+beam with a typical intensity of0.4 pμA was delivered by the Secto...The new thorium isotope 207Th has been produced in the 5n evaporation channel of the fusion reaction 36Ar+176Hf.The 197-199 MeV 36Ar11+beam with a typical intensity of0.4 pμA was delivered by the Sector Focusing Cyclotron of the Heavy Ion Research Facility in Lanzhou(HIRFL),China.展开更多
Proton-andα-decay spectroscopy can provide valuable information on the nuclear structure and masses of neutron-de cient isotopes.In 1994,the proton drip line of Ac was reached by the detection of207Ac which was id...Proton-andα-decay spectroscopy can provide valuable information on the nuclear structure and masses of neutron-de cient isotopes.In 1994,the proton drip line of Ac was reached by the detection of207Ac which was identified via the-decay spectroscopy.Four years later,the neighboring proton-unbound nucleus 206Ac was discov-ered.展开更多
Experiments with 48Ca and 54Cr induced reactions were performed at the gas-filled recoil separator named Spectrometer for Heavy Atoms and Nuclear Structure-2(SHANS2)of the China Accelerator Facility for superhea...Experiments with 48Ca and 54Cr induced reactions were performed at the gas-filled recoil separator named Spectrometer for Heavy Atoms and Nuclear Structure-2(SHANS2)of the China Accelerator Facility for superheavy Elements(CAFE2).The isotopic distributions of nuclei produced in the reactions of 48Ca+243Am,54Cr+243Am,and 54Cr+238U were investigated.Bombardments were conducted at energies near the respective Coulomb barriers,with the SHANS2 magnetic rigidities set to collect fusion-evaporation residues.α-decay spectroscopy was employed to identify products,revealing 58 different isotopes in these experiments.The analysis indicates that the distribution of nuclides produced in different reactions exhibits clear systematic trends.Based on their mass distributions,these nuclei were attributed to the products from the quasi-fission(QF)process.Additionally,several short-lived fission events were identified and attributed to the fission isomers near the target.展开更多
基金supported in part by the National Key R&D Program of China (Contract Nos.2023YFA1606500,2024YFE0109800,and 2024YFE0110400)Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB34010000)+5 种基金the Gansu Key Project of Science and Technology (Grant No.23ZDGA014)the Guangdong Major Project of Basic and Applied Basic Research (Grant No.2021B0301030006)the National Natural Science Foundation of China (Grant Nos.12105328,W2412040,12475126,12422507,12035011,12375118,12435008,and W2412043)the Chinese Academy of Sciences Project for Young Scientists in Basic Research(Grant No.YSBR-002)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (Grant Nos.2020409 and 2023439)the Russian Science Foundation (Grant No.25-42-00003)。
摘要We report the results of the experiment on synthesizing 287,288Mc isotopes (Z=115) using the fusionevaporation reaction 243Am(48Ca,4n,3n)287,288Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-2(SHANS2),a gas-filled recoil separator located at the China Accelerator Facility for Superheavy Elements(CAFE2).In total,20 decay chains are attributed to 288Mc and 1 decay chain is assigned to 287Mc.The measured oa-decay properties of 287,288Mc as well as its descendants are consistent with the known data.No additional decay chains originating from the 2n or 5n reaction channels were detected.The excitation function of the 243Am(48Ca,3n)288Mc reaction was measured at the cross-section level of picobarn,which indicates the promising capability for the study of heavy and superheavy nuclei at the facility.
摘要Fig.3.(a)α-particle energy spectra,and(b)decay-time distributions on a logarithmic scale for the observed 288Mc and its descendant nuclei.In the panel(a),the red histograms show the observed full-energy events,while the corresponding blue histograms show the reconstructed events.The red smooth curves in panel(b)are the expected time distributions according to the corresponding half-lives extracted from this work.
基金Strategic Priority Research Program of Chinese Academy of Sciences(XDB34010000)Guangdong Major Project of Basic and Applied Basic Research(2021B0301030006)+1 种基金National Key R&D Program of China(2018YFA0404402)Frontier Science Key Project of Chinese Academy of Sciences(ZDBS-LY-SLH017)。
摘要The new thorium isotope 207Th has been produced in the 5n evaporation channel of the fusion reaction 36Ar+176Hf.The 197-199 MeV 36Ar11+beam with a typical intensity of0.4 pμA was delivered by the Sector Focusing Cyclotron of the Heavy Ion Research Facility in Lanzhou(HIRFL),China.
基金Strategic Priority Research Program of Chinese Academy of Sciences(XDB34010000)Guangdong Major Project of Basic and Applied Basic Research(2021B0301030006)+4 种基金National Key R&D Program of China(2018YFA0404402)National Natural Science Foundation of China(U1932139,12105328,12035011,U2032135,11975279)Youth Innovation Promotion Association CAS(2020409)CAS Project for Young Scientists in Basic Research(YSBR-002)Special Research Assistant Project of Chinese Academy of Sciences。
摘要Proton-andα-decay spectroscopy can provide valuable information on the nuclear structure and masses of neutron-de cient isotopes.In 1994,the proton drip line of Ac was reached by the detection of207Ac which was identified via the-decay spectroscopy.Four years later,the neighboring proton-unbound nucleus 206Ac was discov-ered.
基金Supported by the Gansu Key Project of Science and Technology(23ZDGA014)the National Key R&D Program of China(2023YFA1606500,2024YFE0109800,2024YFE0110400,2024YFE0110303)+5 种基金the Guangdong Major Project of Basic and Applied Basic Research(2021B0301030006)the National Natural Science Foundation of China(12105328,W2412040,12475126,12422507,12535009,12375118,12435008,W2412043)the CAS Project for Young Scientists in Basic Research(YSBR-002)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2023439)the Russian Science Foundation(25-42-00003)support from CAS President’s international Fellowship Initiative(2026PVA0049)。
摘要Experiments with 48Ca and 54Cr induced reactions were performed at the gas-filled recoil separator named Spectrometer for Heavy Atoms and Nuclear Structure-2(SHANS2)of the China Accelerator Facility for superheavy Elements(CAFE2).The isotopic distributions of nuclei produced in the reactions of 48Ca+243Am,54Cr+243Am,and 54Cr+238U were investigated.Bombardments were conducted at energies near the respective Coulomb barriers,with the SHANS2 magnetic rigidities set to collect fusion-evaporation residues.α-decay spectroscopy was employed to identify products,revealing 58 different isotopes in these experiments.The analysis indicates that the distribution of nuclides produced in different reactions exhibits clear systematic trends.Based on their mass distributions,these nuclei were attributed to the products from the quasi-fission(QF)process.Additionally,several short-lived fission events were identified and attributed to the fission isomers near the target.