We report the results of the experiment on synthesizing ^(287,288)Mc isotopes (Z=115) using the fusionevaporation reaction ^(243)Am(^(48)Ca,4n,3n)^(287,288)Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-...We report the results of the experiment on synthesizing ^(287,288)Mc isotopes (Z=115) using the fusionevaporation reaction ^(243)Am(^(48)Ca,4n,3n)^(287,288)Mc 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 ^(288)Mc and 1 decay chain is assigned to ^(287)Mc.The measured oa-decay properties of ^(287,288)Mc 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 ^(243)Am(^(48)Ca,3n)^(288)Mc 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
Over the past years,experimentalists have launched an expedition to explore the predicted,centered near the double-magic Z=114,N=184 nucleus.With their remarkable e orts,elements from hydrogen up to element 118 at pre...Over the past years,experimentalists have launched an expedition to explore the predicted,centered near the double-magic Z=114,N=184 nucleus.With their remarkable e orts,elements from hydrogen up to element 118 at present.The discovery of the superheavy elements o ers the possibilities to study properties of nuclei under extremely strong Coulomb elds and to explore the limits of existence of nuclei.The fusion evaporation reactions induced by low-energy heavy ions are employed for synthesis and study of superheavy isotopes,and the gas-lled recoil separator technique is always used to e ectively separate the produced evaporation residues from projectile-like and target-like products.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 of^(207)Ac 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 of^(207)Ac which was identified via the-decay spectroscopy.Four years later,the neighboring proton-unbound nucleus ^(206)Ac was discov-ered.展开更多
The new thorium isotope ^(207)Th has been produced in the 5n evaporation channel of the fusion reaction ^(36)Ar+^(176)Hf.The 197-199 MeV ^(36)Ar^(11+)beam with a typical intensity of0.4 pμA was delivered by the Secto...The new thorium isotope ^(207)Th has been produced in the 5n evaporation channel of the fusion reaction ^(36)Ar+^(176)Hf.The 197-199 MeV ^(36)Ar^(11+)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
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)。
文摘We report the results of the experiment on synthesizing ^(287,288)Mc isotopes (Z=115) using the fusionevaporation reaction ^(243)Am(^(48)Ca,4n,3n)^(287,288)Mc 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 ^(288)Mc and 1 decay chain is assigned to ^(287)Mc.The measured oa-decay properties of ^(287,288)Mc 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 ^(243)Am(^(48)Ca,3n)^(288)Mc 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.
文摘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)。
文摘Over the past years,experimentalists have launched an expedition to explore the predicted,centered near the double-magic Z=114,N=184 nucleus.With their remarkable e orts,elements from hydrogen up to element 118 at present.The discovery of the superheavy elements o ers the possibilities to study properties of nuclei under extremely strong Coulomb elds and to explore the limits of existence of nuclei.The fusion evaporation reactions induced by low-energy heavy ions are employed for synthesis and study of superheavy isotopes,and the gas-lled recoil separator technique is always used to e ectively separate the produced evaporation residues from projectile-like and target-like products.
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。
文摘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 of^(207)Ac which was identified via the-decay spectroscopy.Four years later,the neighboring proton-unbound nucleus ^(206)Ac was discov-ered.
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)。
文摘The new thorium isotope ^(207)Th has been produced in the 5n evaporation channel of the fusion reaction ^(36)Ar+^(176)Hf.The 197-199 MeV ^(36)Ar^(11+)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.
