The presolar SiC grains[1]carry the original stellar nucleosynthesis signature.Their isotopic anomalies compared to the sun are the strong constrains in the supernovae(SN)model calculations.The 15N-excess in some SiC-...The presolar SiC grains[1]carry the original stellar nucleosynthesis signature.Their isotopic anomalies compared to the sun are the strong constrains in the supernovae(SN)model calculations.The 15N-excess in some SiC-AB grains(12C/13C<10 and 14N/15N<272)is one of the challenges of core-collapse supernovae(CCSNe)models[2].Recently,Pignatari pointed out that the entrainment of H-rich material into the He shell before the SN explosion allows the coproduction of 13C,15N and 26Al,which provides a new production scenario for SiC-AB grains[2].In the He shell nucleosynthesis,the 13C is produced through 12C(p,γ)13N(β+γ)13C reaction.The 14N is synthesized through 13N(n,γ)and 13C(p,γ)reactions.展开更多
We have found that the excited energy from the ground state with 1f7=2 configuration to the first excited state with 2p3=2 configuration in 37S is obviously lower compared with that in nearby N=21 isotones 35Si, 39A...We have found that the excited energy from the ground state with 1f7=2 configuration to the first excited state with 2p3=2 configuration in 37S is obviously lower compared with that in nearby N=21 isotones 35Si, 39Ar and 41Ca (see Fig. 1, The insert indicates the relevant single-particle orbits of proton and neutron). This interesting phenomenon may result from the collapse of N=28 closure, which gives the sufficient valence space for collective deformation which can been revealed from the B(E2) value. Therefore, to obtain the B(E2), we perform the experiments for measuring the lifetime of the first excited state in 37S.展开更多
Alignment of RIBLL1 is adjusted and the control system of the power supply of the magnets of RIBLL1 is upgraded in 2015. 8 experiments, more than 1 000 h beams, have been carried out at the Radioactive Ion Beam Line i...Alignment of RIBLL1 is adjusted and the control system of the power supply of the magnets of RIBLL1 is upgraded in 2015. 8 experiments, more than 1 000 h beams, have been carried out at the Radioactive Ion Beam Line in Lanzhou (RIBLL1) in 2015. Many research topics are included, such as the mechanism study of -delayed di-proton decay and the correlation measurement of emitted two protons for 22Si and 23Si, elastic scattering of 17F, the study of molecular state of 20O, Coulomb excitation of 37S and decay of 37P, study of the effects of dynamic polarization in low energy reaction induced by the proton-rich exotic nuclei, decay of proton-rich fp shell nuclei with mass around 50.展开更多
In order to study short-lived isotopes with submilisecond half-life and very low recoil energy, some technicalimprovements were made: (1) A VME data acquisition system was introduced to replace the old CAMMAC system.T...In order to study short-lived isotopes with submilisecond half-life and very low recoil energy, some technicalimprovements were made: (1) A VME data acquisition system was introduced to replace the old CAMMAC system.This allows to study isotopes with half-life down to 10 s. (2) Electrical isolation and filtering were introduced,the front end electronic noises have been reduced from 8 MeV down to 2 MeV and the 16 kHz noise producedby the engine of the rotating target system has been removed. (3) A cooling system for the energy degrader wasinstalled and the degrader can be cooled to 0?C.展开更多
The elastic scattering is an important probe to study the properties of a nucleus. An accurate measurement ofthe elastic scattering differential cross section is very important to determine the optical potential param...The elastic scattering is an important probe to study the properties of a nucleus. An accurate measurement ofthe elastic scattering differential cross section is very important to determine the optical potential parameters andthe so-called one quarter angle (q1=4). Also, the optical potential parameters of stable nuclei and unstable nucleiare found to be different. 8B, the binding energy of the last proton is only 0.137 MeV, is a well-known protonhalonucleus even there are still some arguments. Many investigations have been done for 8B by measuring thetotal reaction cross sections, breakup cross section and inelastic scattering differential cross section. However, theexperimental data of elastic scattering of 8B and other light proton-rich nuclei on heavy target are few. Therefore, aseries of experiments have been carried out for such nuclei at the Radioactive Ion Beam Line in Lanzhou (RIBLL).展开更多
The studies of nuclear cluster structure play an important role in understanding of nuclear structure properties.There are lots of works have been done[1?6] to study the nuclear cluster structure properties.. It is a ...The studies of nuclear cluster structure play an important role in understanding of nuclear structure properties.There are lots of works have been done[1?6] to study the nuclear cluster structure properties.. It is a very importantmethod to investigate the nuclear cluster structure through analyzing the breakup reaction of the interesting nucleus.The experimental study of the cluster structure of 9Li through analyzing its breakup fragments was performed atRadioactive Ions Beam Line in Lanzhou (RIBLL). The light charged particles were measured by a ΔE-E telescopearray. Also the energy distribution of the fragments have been measured in this experiment.展开更多
The Rare-Isotope Beam(RIB)Physics Laboratory at IMP has made steady progress in 2022 in the following five aspects.1.Nuclear structure and reaction studies with intermediate-and low-energy RI beams.Measurements of cha...The Rare-Isotope Beam(RIB)Physics Laboratory at IMP has made steady progress in 2022 in the following five aspects.1.Nuclear structure and reaction studies with intermediate-and low-energy RI beams.Measurements of charge-changing cross-sections(CCCS)of^(30-36)P on a^(nat)C target were successfully performed at beam energies around 200-300 MeV/nucleon at the External Target Facility(ETF)of HIRFL to investigate the effect of the N=20 shell closure.展开更多
First measurement of the angular distribution of breakup reaction for^(8)B on a^(208)Pb target at an energy around four times of Coulomb barrier was carried out at the National Laboratory of Heavy Ion Research of Inst...First measurement of the angular distribution of breakup reaction for^(8)B on a^(208)Pb target at an energy around four times of Coulomb barrier was carried out at the National Laboratory of Heavy Ion Research of Institute of Modern Physics.展开更多
基金National Key Research and Development program(MOST 2016YFA0400501),National Natural Science Foundation of China(11490564).
文摘The presolar SiC grains[1]carry the original stellar nucleosynthesis signature.Their isotopic anomalies compared to the sun are the strong constrains in the supernovae(SN)model calculations.The 15N-excess in some SiC-AB grains(12C/13C<10 and 14N/15N<272)is one of the challenges of core-collapse supernovae(CCSNe)models[2].Recently,Pignatari pointed out that the entrainment of H-rich material into the He shell before the SN explosion allows the coproduction of 13C,15N and 26Al,which provides a new production scenario for SiC-AB grains[2].In the He shell nucleosynthesis,the 13C is produced through 12C(p,γ)13N(β+γ)13C reaction.The 14N is synthesized through 13N(n,γ)and 13C(p,γ)reactions.
文摘We have found that the excited energy from the ground state with 1f7=2 configuration to the first excited state with 2p3=2 configuration in 37S is obviously lower compared with that in nearby N=21 isotones 35Si, 39Ar and 41Ca (see Fig. 1, The insert indicates the relevant single-particle orbits of proton and neutron). This interesting phenomenon may result from the collapse of N=28 closure, which gives the sufficient valence space for collective deformation which can been revealed from the B(E2) value. Therefore, to obtain the B(E2), we perform the experiments for measuring the lifetime of the first excited state in 37S.
文摘Alignment of RIBLL1 is adjusted and the control system of the power supply of the magnets of RIBLL1 is upgraded in 2015. 8 experiments, more than 1 000 h beams, have been carried out at the Radioactive Ion Beam Line in Lanzhou (RIBLL1) in 2015. Many research topics are included, such as the mechanism study of -delayed di-proton decay and the correlation measurement of emitted two protons for 22Si and 23Si, elastic scattering of 17F, the study of molecular state of 20O, Coulomb excitation of 37S and decay of 37P, study of the effects of dynamic polarization in low energy reaction induced by the proton-rich exotic nuclei, decay of proton-rich fp shell nuclei with mass around 50.
文摘In order to study short-lived isotopes with submilisecond half-life and very low recoil energy, some technicalimprovements were made: (1) A VME data acquisition system was introduced to replace the old CAMMAC system.This allows to study isotopes with half-life down to 10 s. (2) Electrical isolation and filtering were introduced,the front end electronic noises have been reduced from 8 MeV down to 2 MeV and the 16 kHz noise producedby the engine of the rotating target system has been removed. (3) A cooling system for the energy degrader wasinstalled and the degrader can be cooled to 0?C.
文摘The elastic scattering is an important probe to study the properties of a nucleus. An accurate measurement ofthe elastic scattering differential cross section is very important to determine the optical potential parameters andthe so-called one quarter angle (q1=4). Also, the optical potential parameters of stable nuclei and unstable nucleiare found to be different. 8B, the binding energy of the last proton is only 0.137 MeV, is a well-known protonhalonucleus even there are still some arguments. Many investigations have been done for 8B by measuring thetotal reaction cross sections, breakup cross section and inelastic scattering differential cross section. However, theexperimental data of elastic scattering of 8B and other light proton-rich nuclei on heavy target are few. Therefore, aseries of experiments have been carried out for such nuclei at the Radioactive Ion Beam Line in Lanzhou (RIBLL).
文摘The studies of nuclear cluster structure play an important role in understanding of nuclear structure properties.There are lots of works have been done[1?6] to study the nuclear cluster structure properties.. It is a very importantmethod to investigate the nuclear cluster structure through analyzing the breakup reaction of the interesting nucleus.The experimental study of the cluster structure of 9Li through analyzing its breakup fragments was performed atRadioactive Ions Beam Line in Lanzhou (RIBLL). The light charged particles were measured by a ΔE-E telescopearray. Also the energy distribution of the fragments have been measured in this experiment.
文摘The Rare-Isotope Beam(RIB)Physics Laboratory at IMP has made steady progress in 2022 in the following five aspects.1.Nuclear structure and reaction studies with intermediate-and low-energy RI beams.Measurements of charge-changing cross-sections(CCCS)of^(30-36)P on a^(nat)C target were successfully performed at beam energies around 200-300 MeV/nucleon at the External Target Facility(ETF)of HIRFL to investigate the effect of the N=20 shell closure.
基金National Natural Science Foundation of China(U1632138,11575256,11605253,11705242)。
文摘First measurement of the angular distribution of breakup reaction for^(8)B on a^(208)Pb target at an energy around four times of Coulomb barrier was carried out at the National Laboratory of Heavy Ion Research of Institute of Modern Physics.
