Pulse pile-up is a problem in nuclear spectroscopy and nuclear reaction studies that occurs when two pulses overlap and distort each other,degrading the quality of energy and timing information.Different methods have ...Pulse pile-up is a problem in nuclear spectroscopy and nuclear reaction studies that occurs when two pulses overlap and distort each other,degrading the quality of energy and timing information.Different methods have been used for pile-up rejection,both digital and analogue,but some pile-up events may contain pulses of interest and need to be reconstructed.The paper proposes a new method for reconstructing pile-up events acquired with a neutron detector array(NEDA)using an one-dimensional convolutional autoencoder(1D-CAE).The datasets for training and testing the 1D-CAE are created from data acquired from the NEDA.The new pile-up signal reconstruction method is evaluated from the point of view of how similar the reconstructed signals are to the original ones.Furthermore,it is analysed considering the result of the neutron-gamma discrimination based on charge comparison,comparing the result obtained from original and reconstructed signals.展开更多
The^(6)Li+^(89)Y experiment was performed to explore the reaction mechanism induced by a weakly bound nucleus^(6)Li and its cluster configuration.The particle-γcoincidence method was used to identify the different re...The^(6)Li+^(89)Y experiment was performed to explore the reaction mechanism induced by a weakly bound nucleus^(6)Li and its cluster configuration.The particle-γcoincidence method was used to identify the different reaction channels.Theγ-rays coincident with^(3)He/^(3)H indicate that the^(3)H/^(3)He stripping reaction plays a significant role in the formation of Zr/Nb isotopes.The obtained results support the existence of a^(3)He-^(3)H cluster in^(6)Li.Direct and sequential transfer reactions are adequately discussed,and the FRESCO code is used to perform precise finite-range cyclic redundancy check calculations.In the microscopic calculation,direct cluster transfer is more predominant than sequential transfer in^(3)H transfer.However,the direct cluster transfer is of comparable magnitude to the sequential transfer in the^(3)He transfer.展开更多
The NEutron Detector Array(NEDA)is designed to be coupled to gamma-ray spectrometers to enhance the sensitivity of the setup by enabling reaction channel selection through counting of the evaporated neutrons.This arti...The NEutron Detector Array(NEDA)is designed to be coupled to gamma-ray spectrometers to enhance the sensitivity of the setup by enabling reaction channel selection through counting of the evaporated neutrons.This article presents the implementation of a double trigger condition system for NEDA,which improves the acquisition of neutrons and reduces the number of gamma rays acquired.Two independent triggers are generated in the double trigger condition system:one based on charge comparison(CC)and the other on time-of-flight(TOF).These triggers can be combined using OR and AND logic,offering four distinct trigger modes.The developed firmware is added to the previous one in the Virtex 6 field programmable gate array(FPGA)present in the system,which also includes signal processing,baseline correction,and various trigger logic blocks.The performance of the trigger system is evaluated using data from the E703 experiment performed at GANIL.The four trigger modes are applied to the same data,and a subsequent offline analysis is performed.It is shown that most of the detected neutrons are preserved with the AND mode,and the total number of gamma rays is significantly reduced.Compared with the CC trigger mode,the OR trigger mode allows increasing the selection of neutrons.In addition,it is demonstrated that if the OR mode is selected,the online CC trigger threshold can be raised without losing neutrons.展开更多
An 6 Li+89Y experiment was conducted at the Laboratori Nazinali di Legnaro,INFN,Italy.The 550μg/cm^2 thick^89Y target was backed on a 340μg/cm^2 thick 12C foil.The severalγrays in the experiment with energies highe...An 6 Li+89Y experiment was conducted at the Laboratori Nazinali di Legnaro,INFN,Italy.The 550μg/cm^2 thick^89Y target was backed on a 340μg/cm^2 thick 12C foil.The severalγrays in the experiment with energies higher than 3000 keV can most likely be ascribed to the transitions in the 13C nuclei,which can be formed through various interactions between the 6 Li beam and the 12C foil.The high-energy properties ofγrays in 13C are employed for energy calibrating HPGe detectors,especially for the>3000 keV region,which is impossible to reach by common standard sources(152Eu,133Ba,etc.).Furthermore,γ-γand particle-γcoincidence measurements were performed to investigate the formation of 13C.展开更多
One-neutron stripping process between^(6)Li and^(209)Bi was studied at 28,30,and 34 MeV using the in-beamγ-ray spectroscopy method.Theγ-γcoincident analysis clearly identified twoγ-rays feeding the ground and long...One-neutron stripping process between^(6)Li and^(209)Bi was studied at 28,30,and 34 MeV using the in-beamγ-ray spectroscopy method.Theγ-γcoincident analysis clearly identified twoγ-rays feeding the ground and long-lived isomeric states,which were employed to determine the cross section.The one-neutron stripping cross sections were similar to the cross sections of complete fusion in the^(6)Li+^(209)Bi system,but the one-neutron stripping cross sections decreased more gradually at the sub-barrier region.A coupled-reaction-channel calculation was performed to study the detailed reaction mechanism of the one-neutron stripping process in^(6)Li.The calculations indicated that the first excited state of 5 Li is critical in the actual one-neutron transfer mechanism,and the valence proton of 209Bi can be excited to the low-lying excited state in(^(6)Li,^(5)Li)reaction,unlike in the(d,p)reaction.展开更多
Near degeneracy between two quantum states is usually associated with fundamental symmetries and symmetry breakings in complex many-body systems like atomic nuclei.Pseudospin symmetry was introduced to describe energy...Near degeneracy between two quantum states is usually associated with fundamental symmetries and symmetry breakings in complex many-body systems like atomic nuclei.Pseudospin symmetry was introduced to describe energy degeneracy between single-particle states with quantum numbers(n,l,j=l+1/2)and(n-1,l+2,j=l+3/2)[1-3].展开更多
Backbending played a pivotal role in the progress of high-spin structure research[1].This phennomenon was interpreted as a result of band-crossing between two intrinsic configurations which dominate lower-and higher-s...Backbending played a pivotal role in the progress of high-spin structure research[1].This phennomenon was interpreted as a result of band-crossing between two intrinsic configurations which dominate lower-and higher-spin region.Usually the two configurations are differed by two nucleons,which are paired in the former,and unpaired in the latter.According to the strong-coupling scheme,two unpaired quasi-particles can couple to both high-K and low-K configurations in deformed nuclei.Usually only the lower can be identified experimentally since it is favoured by the Gallagher-Moszkowski spin-spin coupling rules[2].展开更多
Isomeric I^(π)=8^(-) states have been observed in the even-even N=74 nuclei ^(138)Gd[1],^(136)Sm[2],^(134)Nd[3],^(132)Ce[4],^(130)Ba[5],^(128)Xe[6]with half-lives ranging from nanoseconds(Xe)to milliseconds(Ba,Ce).Ro...Isomeric I^(π)=8^(-) states have been observed in the even-even N=74 nuclei ^(138)Gd[1],^(136)Sm[2],^(134)Nd[3],^(132)Ce[4],^(130)Ba[5],^(128)Xe[6]with half-lives ranging from nanoseconds(Xe)to milliseconds(Ba,Ce).Rotational bands built on the K^(π)=8^(-) isomer were identified in all these isotones,with the exception of 130Ba.The singleparticle configuration of the isomers have been deduced from theΔI=2 toΔI=1γ-ray intensity branching ratios,which allowed to extract the(gKgR)/Q0 values,and therefore the quasi-particle configuration of the state.展开更多
The complete and incomplete fusion cross sections for ^(6)Li+^(209)Bi were measured using the in-beamγ-ray method around the Coulomb barrier.The cross sections of(deuteron captured)incomplete fusion(ICF)products were...The complete and incomplete fusion cross sections for ^(6)Li+^(209)Bi were measured using the in-beamγ-ray method around the Coulomb barrier.The cross sections of(deuteron captured)incomplete fusion(ICF)products were re-quantified experimentally for this reaction system.The results reveal that the ICF cross section is equivalent to that of complete fusion(CF)above the Coulomb barrier and dominant near or below the Coulomb barrier.A theoretical calculation based on the continuum discretized coupled channel(CDCC)method was performed for the aforementioned CF and ICF cross sections;the result is consistent with the experiments.The universal fusion function(UFF)was also compared with the measured CF cross section for different barrier parameters,demonstrating that the CF suppression factor is significantly influenced by the choice of potential,which can reflect both dynamic and static effects of breakup on the fusion process.展开更多
Excited states of odd-odd nucleus 92Nb and odd-A nucleus 93Nb were populated in the 6 Li+ 89 Y reaction with an incident energy of 34 MeV. The processes that produce 92,93Nb and can be measured by a combination of lig...Excited states of odd-odd nucleus 92Nb and odd-A nucleus 93Nb were populated in the 6 Li+ 89 Y reaction with an incident energy of 34 MeV. The processes that produce 92,93Nb and can be measured by a combination of light charged particle and gamma ray measurements are discussed. Twenty new transitions are observed and eight new levels are constructed in 92Nb, and in addition two new transitions are added to the level scheme of 93Nb. Using shell2 model calculations, the low-lying structure of 9 Nb is investigated and compared with the experimental results.展开更多
基金partially supported by MICIU MCIN/AEI/10.13039/501100011033Spain with grant PID2020-118265GB-C42,-C44,PRTR-C17.I01+1 种基金Generalitat Valenciana,Spain with grant CIPROM/2022/54,ASFAE/2022/031,CIAPOS/2021/114the EU NextGenerationEU,ESF funds,and the National Science Centre (NCN),Poland (grant No.2020/39/D/ST2/00466)
文摘Pulse pile-up is a problem in nuclear spectroscopy and nuclear reaction studies that occurs when two pulses overlap and distort each other,degrading the quality of energy and timing information.Different methods have been used for pile-up rejection,both digital and analogue,but some pile-up events may contain pulses of interest and need to be reconstructed.The paper proposes a new method for reconstructing pile-up events acquired with a neutron detector array(NEDA)using an one-dimensional convolutional autoencoder(1D-CAE).The datasets for training and testing the 1D-CAE are created from data acquired from the NEDA.The new pile-up signal reconstruction method is evaluated from the point of view of how similar the reconstructed signals are to the original ones.Furthermore,it is analysed considering the result of the neutron-gamma discrimination based on charge comparison,comparing the result obtained from original and reconstructed signals.
基金supported by the National Natural Science Foundation of China under Grant Nos.U2167204,11975040,111 Center(B20065)Brazilian authors were supported in part by local funding agencies CNPq+10 种基金FAPERJCAPESand INCT-FNA(Instituto Nacional de Ciência e Tecnologia,Física Nuclear e Aplicacoes)Research Project No.464898/2014-5Marco Siciliano's work was partially supported by the US Department of EnergyOffice of Scienceand Office of Nuclear Physics(DE-AC02-06CH11357)supported by Nuclear Energy Development and Research Project No.HNKF202224(28)Ling Chuang Research Project of the China National Nuclear Corporation No.CNNCLCKY-2023 and No.20221024000072F6-0002-7Guangdong Key Research and Development Program No.2020B040420005Guangdong Basic and Applied Basic Research Foundation No.2021B1515120027。
文摘The^(6)Li+^(89)Y experiment was performed to explore the reaction mechanism induced by a weakly bound nucleus^(6)Li and its cluster configuration.The particle-γcoincidence method was used to identify the different reaction channels.Theγ-rays coincident with^(3)He/^(3)H indicate that the^(3)H/^(3)He stripping reaction plays a significant role in the formation of Zr/Nb isotopes.The obtained results support the existence of a^(3)He-^(3)H cluster in^(6)Li.Direct and sequential transfer reactions are adequately discussed,and the FRESCO code is used to perform precise finite-range cyclic redundancy check calculations.In the microscopic calculation,direct cluster transfer is more predominant than sequential transfer in^(3)H transfer.However,the direct cluster transfer is of comparable magnitude to the sequential transfer in the^(3)He transfer.
基金supported by MICIU MCIN/AEI/10.13039/501100011033Spain with Grant PID2020-118265GB-C42,-C44,PRTR-C17.I01Generalitat Valenciana,Spain with Grant CIPROM/2022/54,ASFAE/2022/031,CIAPOS/2021/114 and by the EU NextGenerationEU,ESF funds.This work was also supported by the National Science Centre(NCN),Poland(Grant No.2020/39/D/ST2/00466).
文摘The NEutron Detector Array(NEDA)is designed to be coupled to gamma-ray spectrometers to enhance the sensitivity of the setup by enabling reaction channel selection through counting of the evaporated neutrons.This article presents the implementation of a double trigger condition system for NEDA,which improves the acquisition of neutrons and reduces the number of gamma rays acquired.Two independent triggers are generated in the double trigger condition system:one based on charge comparison(CC)and the other on time-of-flight(TOF).These triggers can be combined using OR and AND logic,offering four distinct trigger modes.The developed firmware is added to the previous one in the Virtex 6 field programmable gate array(FPGA)present in the system,which also includes signal processing,baseline correction,and various trigger logic blocks.The performance of the trigger system is evaluated using data from the E703 experiment performed at GANIL.The four trigger modes are applied to the same data,and a subsequent offline analysis is performed.It is shown that most of the detected neutrons are preserved with the AND mode,and the total number of gamma rays is significantly reduced.Compared with the CC trigger mode,the OR trigger mode allows increasing the selection of neutrons.In addition,it is demonstrated that if the OR mode is selected,the online CC trigger threshold can be raised without losing neutrons.
基金supported by the National Natural Science Foundation of China(Nos.11975040,U1832130,11475013)the HIRFL User Project,CAS.
文摘An 6 Li+89Y experiment was conducted at the Laboratori Nazinali di Legnaro,INFN,Italy.The 550μg/cm^2 thick^89Y target was backed on a 340μg/cm^2 thick 12C foil.The severalγrays in the experiment with energies higher than 3000 keV can most likely be ascribed to the transitions in the 13C nuclei,which can be formed through various interactions between the 6 Li beam and the 12C foil.The high-energy properties ofγrays in 13C are employed for energy calibrating HPGe detectors,especially for the>3000 keV region,which is impossible to reach by common standard sources(152Eu,133Ba,etc.).Furthermore,γ-γand particle-γcoincidence measurements were performed to investigate the formation of 13C.
基金the National Nature Science Foundation of China(Nos.U2167204,11975040,and U1832130)the Brazilian funding agencies CAPES,CNPq,FAPERJ,and the INCT-FNA(Instituto Nacional de Ciência e Tecnologia-Física Nuclear e Aplicações)+5 种基金research project 464898/2014-5.S.P.Hu was supported by Guang dong Key Research And Development Program(No.2020B040420005)Guang dong Basic and Applied Basic Research Foundation(No.2021B1515120027)Ling Chuang Research Project of China National Nuclear Corporation(No.20221024000072F6-0002-7)Nuclear Energy Development and Research Project(No.HNKF202224(28))the‘111’center(B20065)the U.S.Department of Energy,Office of Science,Office of Nuclear Physics,under contract number DE-AC02-06CH1135.
文摘One-neutron stripping process between^(6)Li and^(209)Bi was studied at 28,30,and 34 MeV using the in-beamγ-ray spectroscopy method.Theγ-γcoincident analysis clearly identified twoγ-rays feeding the ground and long-lived isomeric states,which were employed to determine the cross section.The one-neutron stripping cross sections were similar to the cross sections of complete fusion in the^(6)Li+^(209)Bi system,but the one-neutron stripping cross sections decreased more gradually at the sub-barrier region.A coupled-reaction-channel calculation was performed to study the detailed reaction mechanism of the one-neutron stripping process in^(6)Li.The calculations indicated that the first excited state of 5 Li is critical in the actual one-neutron transfer mechanism,and the valence proton of 209Bi can be excited to the low-lying excited state in(^(6)Li,^(5)Li)reaction,unlike in the(d,p)reaction.
文摘Near degeneracy between two quantum states is usually associated with fundamental symmetries and symmetry breakings in complex many-body systems like atomic nuclei.Pseudospin symmetry was introduced to describe energy degeneracy between single-particle states with quantum numbers(n,l,j=l+1/2)and(n-1,l+2,j=l+3/2)[1-3].
文摘Backbending played a pivotal role in the progress of high-spin structure research[1].This phennomenon was interpreted as a result of band-crossing between two intrinsic configurations which dominate lower-and higher-spin region.Usually the two configurations are differed by two nucleons,which are paired in the former,and unpaired in the latter.According to the strong-coupling scheme,two unpaired quasi-particles can couple to both high-K and low-K configurations in deformed nuclei.Usually only the lower can be identified experimentally since it is favoured by the Gallagher-Moszkowski spin-spin coupling rules[2].
文摘Isomeric I^(π)=8^(-) states have been observed in the even-even N=74 nuclei ^(138)Gd[1],^(136)Sm[2],^(134)Nd[3],^(132)Ce[4],^(130)Ba[5],^(128)Xe[6]with half-lives ranging from nanoseconds(Xe)to milliseconds(Ba,Ce).Rotational bands built on the K^(π)=8^(-) isomer were identified in all these isotones,with the exception of 130Ba.The singleparticle configuration of the isomers have been deduced from theΔI=2 toΔI=1γ-ray intensity branching ratios,which allowed to extract the(gKgR)/Q0 values,and therefore the quasi-particle configuration of the state.
基金Supported by the National Nature Science Foundation of China(U2167204,11975040,1832130)The Brazilian authors thank the partial financial support from CNPq,FAPERJ,and INCT-FNA(Instituto Nacional de Ciência e Tecnologia,Física Nuclear e Aplicações),research Project No.(464898/2014-5)+4 种基金supported by(M.S.)the U.S.Department of Energy,Office of Science,and Office of Nuclear Physics(DE-AC02-06CH11357)supported By the Key Research and Development Program of Guangdong Province,China(2020B040420005)the Basic and Applied Basic Research Foundation of Guangdong Province,China(2021B1515120027)LingChuang Research Project of China National Nuclear Corporation(20221024000072F6-0002-7)the Nuclear Energy Development and Research Project(HNKF202224(28)),and the'111'Center(B20065).
文摘The complete and incomplete fusion cross sections for ^(6)Li+^(209)Bi were measured using the in-beamγ-ray method around the Coulomb barrier.The cross sections of(deuteron captured)incomplete fusion(ICF)products were re-quantified experimentally for this reaction system.The results reveal that the ICF cross section is equivalent to that of complete fusion(CF)above the Coulomb barrier and dominant near or below the Coulomb barrier.A theoretical calculation based on the continuum discretized coupled channel(CDCC)method was performed for the aforementioned CF and ICF cross sections;the result is consistent with the experiments.The universal fusion function(UFF)was also compared with the measured CF cross section for different barrier parameters,demonstrating that the CF suppression factor is significantly influenced by the choice of potential,which can reflect both dynamic and static effects of breakup on the fusion process.
基金Supported by National Natural Science Foundation of China(U1867210,11775098,11475013,U1832130 and 11775316)
文摘Excited states of odd-odd nucleus 92Nb and odd-A nucleus 93Nb were populated in the 6 Li+ 89 Y reaction with an incident energy of 34 MeV. The processes that produce 92,93Nb and can be measured by a combination of light charged particle and gamma ray measurements are discussed. Twenty new transitions are observed and eight new levels are constructed in 92Nb, and in addition two new transitions are added to the level scheme of 93Nb. Using shell2 model calculations, the low-lying structure of 9 Nb is investigated and compared with the experimental results.
