The first 2^(+)excited states of the nucleus directly reflect the interaction between the shell structure and the nucleus,providing insights into the validity of the shell model and nuclear structure characteristics.A...The first 2^(+)excited states of the nucleus directly reflect the interaction between the shell structure and the nucleus,providing insights into the validity of the shell model and nuclear structure characteristics.Although the features of the first 2^(+)excited states can be measured for stable nuclei and calculated using nuclear models,significant uncertainty remains.This study employs a machine learning model based on a light gradient boosting machine(LightGBM)to investigate the first 2^(+)excited states.Specifically,the training of the LightGBM algorithm and the prediction of the first 2^(+)properties of 642 nuclei are presented.Furthermore,detailed comparisons of the LightGBM predictions were performed with available experimental data,shell model calculations,and Bayesian neural network predictions.The results revealed that the average difference between the LightGBM predictions and the experimental data was 18 times smaller than that obtained by the shell model and only 70%of the BNN prediction results.Considering Mg,Ca,Kr,Sm,and Pb isotopes as examples,it was also observed that LightGBM can effectively reproduce the magic number mutation caused by shell effects,with the energy being as low as 0.04 MeV due to shape coexistence.Therefore,we believe that leveraging LightGBM-based machine learning can profoundly enhance our insights into nuclear structures and provide new avenues for nuclear physics research.展开更多
High-power laser systems have opened new frontiers in scientifi research and have revolutionized various scientifi fields offering unprecedented capabilities for understanding fundamental physics and allowing unique a...High-power laser systems have opened new frontiers in scientifi research and have revolutionized various scientifi fields offering unprecedented capabilities for understanding fundamental physics and allowing unique applications.This paper details the successful commissioning of the 1 PW experimental area at the Extreme Light Infrastructure–Nuclear Physics(ELI-NP)facility in Romania,using both of the available laser arms.The experimental setup featured a short focal parabolic mirror to accelerate protons through the target normal sheath acceleration mechanism.Detailed experiments were conducted using various metallic and diamond-like carbon targets to investigate the dependence of the proton acceleration on different laser parameters.Furthermore,the paper discusses the critical role of the laser temporal profil in optimizing proton acceleration,supported by hydrodynamic simulations that are correlated with experimental outcomes.The finding underscore the potential of the ELI-NP facility to advance research in laser–plasma physics and contribute significantl to high-energy physics applications.The results of this commissioning establish a strong foundation for experiments by future users.展开更多
The emergence of a new era reaching beyond current state-of-the-art ultrashort and ultraintense laser technology has been enabled by the approval of around V 850 million worth of structural funds in 2011–2012 by the ...The emergence of a new era reaching beyond current state-of-the-art ultrashort and ultraintense laser technology has been enabled by the approval of around V 850 million worth of structural funds in 2011–2012 by the European Commission for the installation of Extreme Light Infrastructure(ELI).The ELI project consists of three pillars being built in the Czech Republic,Hungary,and Romania.This challenging proposal is based on recent technical progress allowing ultraintense laser fields in which intensities will soon be reaching as high as I0∼1023Wcm−2.This tremendous technological advance has been brought about by the invention of chirped pulse amplification by Mourou and Strickland.Romania is hosting the ELI for Nuclear Physics(ELI-NP)pillar in M˘agurele near Bucharest.The new facility,currently under construction,is intended to serve the broad national,European,and international scientific community.Its mission covers scientific research at the frontier of knowledge involving two domains.The first is laser-driven experiments related to NP,strong-field quantum electrodynamics,and associated vacuum effects.The second research domain is based on the establishment of a Compton-backscattering-based,high-brilliance,and intenseγbeam with Eγ≲19.5 MeV,which represents a merger between laser and accelerator technology.This system will allow the investigation of the nuclear structure of selected isotopes and nuclear reactions of relevance,for example,to astrophysics with hitherto unprecedented resolution and accuracy.In addition to fundamental themes,a large number of applications with significant societal impact will be developed.The implementation of the project started in January 2013 and is spearheaded by the ELI-NP/Horia Hulubei National Institute for Physics and Nuclear Engineering(IFIN-HH).Experiments will begin in early 2020.展开更多
Copper-64 is a radioisotope of medical interest that could be used for positron emission tomography imaging and targeted radiotherapy of cancer. In this work,we investigated the possibility of producing the^(64)Cu iso...Copper-64 is a radioisotope of medical interest that could be used for positron emission tomography imaging and targeted radiotherapy of cancer. In this work,we investigated the possibility of producing the^(64)Cu isotope through a^(65)Cu(γ,n) reaction using high-intensity γ-beams produced at the Extreme Light InfrastructureNuclear Physics facility(ELI-NP). The specific activity for^(64)Cu was obtained as a function of target geometry, irradiation time, and electron beam energy, which translates into γ-beam energy. Optimized conditions for the generation of^(64)Cu isotopes at the ELI-NP were discussed. We estimated that an achievable saturation specific activity is of the order of 1–2 m Ci/g for thin targets(radius 1–2 mm,thickness 1 cm) and for a γ-beam flux of 10^(11) s ~1. Based on these results, the ELI-NP could provide great potential for the production of some innovative radioisotopes of medical interest in sufficient quantities suitable for nuclear medicine research.展开更多
For simulating more accurately neutron or proton production from photonuclear reactions,a data-based photonuclear reaction simulation algorithm has been developed.Reliable photonuclear cross sections from evaluated or...For simulating more accurately neutron or proton production from photonuclear reactions,a data-based photonuclear reaction simulation algorithm has been developed.Reliable photonuclear cross sections from evaluated or experimental database are chosen as input data.For checking the validity of the use of the data-based photonuclear algorithm,benchmarking simulations are presented in detail.We calculate photonuclear cross sections or reaction yield for ~9Be,^(48)Ti,^(133)Cs,and ^(197)Au and compare them with experimental data in the region of incident photon energy below ~30 MeV.While Geant4 can hardly reproduce photonuclear experimental data,results obtained from the data-based photonuclear algorithm are found in good agreement with experimental measurements.Potential application in estimation of specific activity of radioisotopes is further discussed.We conclude that the developed data-based photonuclear algorithm is suitable for an accurate prediction of photoninduced neutron or proton productions.展开更多
The interaction of micro-bubbles with ultra-intense laser pulses has been shown to generate ultra-high proton densities and correspondingly high electric fields.Weinvestigate the possibility of using such a combinatio...The interaction of micro-bubbles with ultra-intense laser pulses has been shown to generate ultra-high proton densities and correspondingly high electric fields.Weinvestigate the possibility of using such a combination to study the fundamental physical phenomenon of vacuum polarization.With current or near-future laser systems,measurement of vacuum polarization via the bending of gamma rays that pass near imploded microbubbles may be possible.Since it is independent of photon energy to within the leading-order solution of the Heisenberg–Euler Lagrangian and the geometric optics approximation,the corresponding index of refraction can dominate the indices of refraction due to other effects at sufficiently high photon energies.We consider the possibility of its application to a transient gamma-ray lens.展开更多
Heavy-ion fusion reactions between light nuclei such as carbon and oxygen isotopes have been studied becauseof their importance in a wide variety of stellar burning scenarios. However, due to extremely low cross secti...Heavy-ion fusion reactions between light nuclei such as carbon and oxygen isotopes have been studied becauseof their importance in a wide variety of stellar burning scenarios. However, due to extremely low cross sectionsand signal/background ratio, all the measurements could only be carried out at energies well above the regionof astrophysical interest. The reaction rates in stellar environment could be estimated only by extrapolating theexisted cross sections or the astrophysical S-factors at higher energies. The situation is even more complicated bythe strong, relatively narrow resonances in some reactions, such as 12C+12C, 12C+16O. Traditionally, optical modelor equivalent square-well optical model (ESW) were used to fit the average cross section and predict the reactioncross sections at the energies of astrophysical interest[1]. Recently, a new model, the hindrance model, was proposedto provide systematic fits to fusion reaction data at extreme sub-barrier energies[2]. Lacking of experimental datawithin this energy range, large discrepancies exist among different nuclear reaction models.展开更多
We present a novel scheme for rapid quantitative analysis of debris generated during experiments with solid targets following relativistic laser–plasma interaction at high-power laser facilities.Results are supported...We present a novel scheme for rapid quantitative analysis of debris generated during experiments with solid targets following relativistic laser–plasma interaction at high-power laser facilities.Results are supported by standard analysis techniques.Experimental data indicate that predictions by available modelling for non-mass-limited targets are reasonable,with debris of the order of hundreds ofμg per shot.We detect for the first time two clearly distinct types of debris emitted from the same interaction.A fraction of the debris is ejected directionally,following the target normal(rear and interaction side).The directional debris ejection towards the interaction side is larger than on the side of the target rear.The second type of debris is characterized by a more spherically uniform ejection,albeit with a small asymmetry that favours ejection towards the target rear side.展开更多
We are showing a significant enhancement in the temporal contrast by reducing the coherent noise of the 10 PW laser system at the Extreme Light Infrastructure-Nuclear Physics facility. The temporal contrast was improv...We are showing a significant enhancement in the temporal contrast by reducing the coherent noise of the 10 PW laser system at the Extreme Light Infrastructure-Nuclear Physics facility. The temporal contrast was improved by four orders of magnitude at 10 picoseconds and by more than one order of magnitude at 50 picoseconds before the main peak. This improvement of the picosecond contrast is critical for the experiments using thin solid targets.展开更多
With ultrafast laser systems reaching presently 10 PW peak power or operating at high repetition rates,research towards ensuring the long-term,trouble-free performance of all laser-exposed optical components is critic...With ultrafast laser systems reaching presently 10 PW peak power or operating at high repetition rates,research towards ensuring the long-term,trouble-free performance of all laser-exposed optical components is critical.Our work is focused on providing insight into the optical material behavior at fluences below the standardized laser-induced damage threshold(LIDT)value by implementing a simultaneous dual analysis of surface emitted particles using a Langmuir probe(LP)and the target current(TC).HfO_(2) and ZrO_(2) thin films deposited on fused silica substrates by pulsed laser deposition at various O_(2) pressures for defect and stoichiometry control were irradiated by Gaussian,ultrashort laser pulses(800 nm,10 Hz,70 fs)in a wide range of fluences.Both TC and LP collected signals were in good agreement with the existing theoretical description of laser–matter interaction at an ultrashort time scale.Our approach for an in situ LIDT monitoring system provides measurable signals for below-threshold irradiation conditions that indicate the endurance limit of the optical surfaces in the single-shot energy scanning mode.The LIDT value extracted from the LP-TC system is in line with the multipulse statistical analysis done with ISO 21254-2:2011(E).The implementation of the LP and TC as on-shot diagnostic tools for optical components will have a significant impact on the reliability of next-generation ultrafast and high-power laser systems.展开更多
We report on the generation and delivery of 10.2 PW peak power laser pulses,using the High Power Laser System at the Extreme Laser Infrastructure–Nuclear Physics facility.In this work we demonstrate for the first tim...We report on the generation and delivery of 10.2 PW peak power laser pulses,using the High Power Laser System at the Extreme Laser Infrastructure–Nuclear Physics facility.In this work we demonstrate for the first time,to the best of our knowledge,the compression and propagation of full energy,full aperture,laser pulses that reach a power level of more than 10 PW.展开更多
In this paper we present a comparative study between PYTHIA, EPOS, QGSJET, and SIBYLL generators. The global event observables considered are the charged energy flow, charged particle distributions, charged hadron pro...In this paper we present a comparative study between PYTHIA, EPOS, QGSJET, and SIBYLL generators. The global event observables considered are the charged energy flow, charged particle distributions, charged hadron production ratios and V^0 ratios. The study is performed in the LHCb and TOTEM fiducial phase spaces on minimum bias simulated data samples for pp collisions at = 7 TeV , using the reference measurements from these experiments. In the majority of cases, the measurements are within a band defined by the most extreme predictions. The observed differences between the predictions and the measurements seem to be, in most part, caused by extrapolation from the central pseudorapidity region (|η| 2.5), in which the generators were mainly tuned.展开更多
Spectral-broadening of the APOLLON PW-class laser pulses using a thin-film compression technique within the longfocal-area interaction chamber of the APOLLON laser facility is reported,demonstrating the delivery of th...Spectral-broadening of the APOLLON PW-class laser pulses using a thin-film compression technique within the longfocal-area interaction chamber of the APOLLON laser facility is reported,demonstrating the delivery of the full energy pulse to the target interaction area.The laser pulse at 7 J passing through large aperture,thin glass wafers is spectrally broadened to a bandwidth that is compatible with a 15-fs pulse,indicating also the possibility to achieve sub-10-fs pulses using 14 J.Placing the post-compressor near the interaction makes for an economical method to produce the shortest pulses by limiting the need for high damage,broadband optics close to the final target rather than throughout the entire laser transport system.展开更多
The post-compression technique based on self-phase modulation of high-energy pulses leads to an increase in achievable peak power and intensity.Typically,the pulses considered in experiments have been less than 100 fs...The post-compression technique based on self-phase modulation of high-energy pulses leads to an increase in achievable peak power and intensity.Typically,the pulses considered in experiments have been less than 100 fs in duration.Here,the method is applied to the ELFIE laser system at the LULI facility,for a pulse of 7 J energy and an initial measured duration of 350 fs.A 5-mm-thick fused silica window and a 2 mm cyclic-olefin polymer were used as optical nonlinear materials.The 9 cm diameter beam was spectrally broadened to a bandwidth corresponding to 124 fs Fourier-limited pulse duration,and then it was partly post-compressed to 200 fs.After measuring the spatial spectra of the beam fluence,a uniform gain factor of 4 increase in the fluctuations over the studied range of frequencies is observed,due to small-scale self-focusing.展开更多
A number of laser facilities coming online all over the world promise the capability of high-power laser experiments with shot repetition rates between 1 and 10 Hz. Target availability and technical issues related to ...A number of laser facilities coming online all over the world promise the capability of high-power laser experiments with shot repetition rates between 1 and 10 Hz. Target availability and technical issues related to the interaction environment could become a bottleneck for the exploitation of such facilities. In this paper, we report on target needs for three different classes of experiments: dynamic compression physics, electron transport and isochoric heating, and laser-driven particle and radiation sources. We also review some of the most challenging issues in target fabrication and high repetition rate operation. Finally, we discuss current target supply strategies and future perspectives to establish a sustainable target provision infrastructure for advanced laser facilities.展开更多
True ternary fission and Tin-accompanied ternary fission of 242Pu are studied by using the'Three Cluster Model'.True ternary fission is considered as a formation of heavy fragments in the region 28≤Z1,Z2,Z3≤...True ternary fission and Tin-accompanied ternary fission of 242Pu are studied by using the'Three Cluster Model'.True ternary fission is considered as a formation of heavy fragments in the region 28≤Z1,Z2,Z3≤38 with comparable masses.The possible fission channels are predicted by the potential-energy calculations.Interaction potentials,Q-values and relative yields for all possible fragmentations in equatorial and collinear configurations are calculated and compared.It is found that ternary fission with formation of a double magic nucleus like 132Sn is more probable than the other fragmentations.Also,the kinetic energies of the fragments for the group Z1=32,Z2=32 and Z3=30 are calculated for all combinations in the collinear geometry as a sequential decay.展开更多
An experiment aimed to investigate the two-proton(2p) decay of the previously unknown nucleus ^(30)Ar was performed at GSI. By tracking the decay products in-flight with silicon micro-strip detectors, the 2p decays of...An experiment aimed to investigate the two-proton(2p) decay of the previously unknown nucleus ^(30)Ar was performed at GSI. By tracking the decay products in-flight with silicon micro-strip detectors, the 2p decays of ^(30)Ar were observed for the first time. For the calibration purpose, 2p decays of ^(19)Mg were also remeasured by tracking the coincident ^(17)Ne+p+p trajectories. By comparing the measured angular p-17 Ne correlations with those obtained from the corresponding Monte Carlo simulations,the simultaneous 2p decay of ^(19)Mg ground state and the sequential 2p emission of several known excited states of ^(19)Mg were confirmed. One new excited state in ^(19)Mg and two new excited states in ^(18)Na were observed.展开更多
The spatial distribution of beams with orbital angular momentum in the far field is known to be extremely sensitive to angular aberrations,such as astigmatism,coma and trefoil.This poses a challenge for conventional b...The spatial distribution of beams with orbital angular momentum in the far field is known to be extremely sensitive to angular aberrations,such as astigmatism,coma and trefoil.This poses a challenge for conventional beam optimization strategies when a homogeneous ring intensity is required for an application.We developed a novel approach for estimating the Zernike coefficients of low-order angular aberrations in the near field based solely on the analysis of the ring deformations in the far field.A fast,iterative reconstruction of the focal ring recreates the deformations and provides insight into the wavefront deformations in the near field without relying on conventional phase retrieval approaches.The output of our algorithm can be used to optimize the focal ring,as demonstrated experimentally at the 100 TW beamline at the Extreme Light Infrastructure-Nuclear Physics facility.展开更多
The future experimental campaign with the SAMURAI setup at RIKEN will explore a wide range of neutron-deficient nuclei with a particular focus on the most critical(p, γ) reaction rates relevant to the astrophysical r...The future experimental campaign with the SAMURAI setup at RIKEN will explore a wide range of neutron-deficient nuclei with a particular focus on the most critical(p, γ) reaction rates relevant to the astrophysical rp-process in type-I X-ray bursts(XRB). Intense radioactive-ion(RI) beams at an energy of a few hundred Me V/nucleon will be deployed to populate proton-unbound states in the nuclei of interest through the Coulomb excitation or nucleon-removal processes. The decay of these states into a proton and a heavy residue will be measured using complete kinematics and the information about time reversal proton-capture process will be obtained. This method will provide the vital experimental data on the resonances, which dominate the stellar(p, γ) reaction rates, as well as on the direct proton-capture process for some other cases. The experimental setup will utilize for the first time the High-Resolution90?-mode of the SAMURAI spectrometer in combination with the existing detection systems, including custom-designed Si-strip detectors for simultaneous detection and tracking of heavy ions and protons emitted from the target. The details of the experimental method and the utilized apparatus are discussed in this paper.展开更多
The β^+ decay of ^(31)Ar was investigated in an experiment at the GSI-FRS spectrometer.The ions of interest have been produced in the fragmentation of a ^(36)Ar beam at 880 Me V/nucleon and implanted in a time projec...The β^+ decay of ^(31)Ar was investigated in an experiment at the GSI-FRS spectrometer.The ions of interest have been produced in the fragmentation of a ^(36)Ar beam at 880 Me V/nucleon and implanted in a time projection chamber with optical readout. In addition to β-delayed one and two proton emission, for the first time the emission of β-delayed 3 protons has been observed. The branching ratio for this decay mode is found to be(0.07 ± 0.02)%.展开更多
基金supported by the National Key R&D Program of China (No. 2022YFA1603300)the Romanian Ministry of Research,Innovation and Digitalization under Contract PN 23.21.01.06+1 种基金The ELI-RO project with Contract ELI-RORDI-2024-008 (AMAP)a grant from the Romanian Ministry of Research,Innovation and Digitization,CNCS-UEFIS-CDI,with project numbers PN-Ⅲ-P4-PCE-2021-1014, PN-Ⅲ-P4-PCE-2021-0595, and PN-Ⅲ-P1-1.1-TE2021-1464 within PNCDI Ⅲ
文摘The first 2^(+)excited states of the nucleus directly reflect the interaction between the shell structure and the nucleus,providing insights into the validity of the shell model and nuclear structure characteristics.Although the features of the first 2^(+)excited states can be measured for stable nuclei and calculated using nuclear models,significant uncertainty remains.This study employs a machine learning model based on a light gradient boosting machine(LightGBM)to investigate the first 2^(+)excited states.Specifically,the training of the LightGBM algorithm and the prediction of the first 2^(+)properties of 642 nuclei are presented.Furthermore,detailed comparisons of the LightGBM predictions were performed with available experimental data,shell model calculations,and Bayesian neural network predictions.The results revealed that the average difference between the LightGBM predictions and the experimental data was 18 times smaller than that obtained by the shell model and only 70%of the BNN prediction results.Considering Mg,Ca,Kr,Sm,and Pb isotopes as examples,it was also observed that LightGBM can effectively reproduce the magic number mutation caused by shell effects,with the energy being as low as 0.04 MeV due to shape coexistence.Therefore,we believe that leveraging LightGBM-based machine learning can profoundly enhance our insights into nuclear structures and provide new avenues for nuclear physics research.
基金supported by the Extreme Light Infrastructure–Nuclear Physics(ELI-NP)PhaseⅡa project co-finance by the Romanian Government and the European Union through the European Regional Development Fund,by the Romanian Ministry of Education and Research CNCS-UEFISCDI(Project No.PN-ⅡIP4-IDPCCF-2016-0164)+1 种基金Nucleu Projects(Grant No.PN 23210105 and 19060105)supports ELI-NP through IOSIN funds as a Facility of National Interest。
文摘High-power laser systems have opened new frontiers in scientifi research and have revolutionized various scientifi fields offering unprecedented capabilities for understanding fundamental physics and allowing unique applications.This paper details the successful commissioning of the 1 PW experimental area at the Extreme Light Infrastructure–Nuclear Physics(ELI-NP)facility in Romania,using both of the available laser arms.The experimental setup featured a short focal parabolic mirror to accelerate protons through the target normal sheath acceleration mechanism.Detailed experiments were conducted using various metallic and diamond-like carbon targets to investigate the dependence of the proton acceleration on different laser parameters.Furthermore,the paper discusses the critical role of the laser temporal profil in optimizing proton acceleration,supported by hydrodynamic simulations that are correlated with experimental outcomes.The finding underscore the potential of the ELI-NP facility to advance research in laser–plasma physics and contribute significantl to high-energy physics applications.The results of this commissioning establish a strong foundation for experiments by future users.
基金The contribution of the entire ELI-NP team and collaborators to the project implementation is gratefully acknowledged,especially the help of A.Imreh in creating the complex 3D figures.The work has been supported by Extreme Light Infrastructure Nuclear Physics Phase II,a project co-financed by the Romanian Government and the European Union through the European Regional Development Fund and the Competitiveness Operational Programme(No.1/07.07.2016,COP,ID 1334).
文摘The emergence of a new era reaching beyond current state-of-the-art ultrashort and ultraintense laser technology has been enabled by the approval of around V 850 million worth of structural funds in 2011–2012 by the European Commission for the installation of Extreme Light Infrastructure(ELI).The ELI project consists of three pillars being built in the Czech Republic,Hungary,and Romania.This challenging proposal is based on recent technical progress allowing ultraintense laser fields in which intensities will soon be reaching as high as I0∼1023Wcm−2.This tremendous technological advance has been brought about by the invention of chirped pulse amplification by Mourou and Strickland.Romania is hosting the ELI for Nuclear Physics(ELI-NP)pillar in M˘agurele near Bucharest.The new facility,currently under construction,is intended to serve the broad national,European,and international scientific community.Its mission covers scientific research at the frontier of knowledge involving two domains.The first is laser-driven experiments related to NP,strong-field quantum electrodynamics,and associated vacuum effects.The second research domain is based on the establishment of a Compton-backscattering-based,high-brilliance,and intenseγbeam with Eγ≲19.5 MeV,which represents a merger between laser and accelerator technology.This system will allow the investigation of the nuclear structure of selected isotopes and nuclear reactions of relevance,for example,to astrophysics with hitherto unprecedented resolution and accuracy.In addition to fundamental themes,a large number of applications with significant societal impact will be developed.The implementation of the project started in January 2013 and is spearheaded by the ELI-NP/Horia Hulubei National Institute for Physics and Nuclear Engineering(IFIN-HH).Experiments will begin in early 2020.
基金supported by Extreme Light Infrastructure-Nuclear Physics(ELI-NP)-Phase Ia project co-financed by the European Union through the European Regional Development Fund+1 种基金the National Natural Science Foundation of China(No.11405083)the Young Talent Project of the University of South China
文摘Copper-64 is a radioisotope of medical interest that could be used for positron emission tomography imaging and targeted radiotherapy of cancer. In this work,we investigated the possibility of producing the^(64)Cu isotope through a^(65)Cu(γ,n) reaction using high-intensity γ-beams produced at the Extreme Light InfrastructureNuclear Physics facility(ELI-NP). The specific activity for^(64)Cu was obtained as a function of target geometry, irradiation time, and electron beam energy, which translates into γ-beam energy. Optimized conditions for the generation of^(64)Cu isotopes at the ELI-NP were discussed. We estimated that an achievable saturation specific activity is of the order of 1–2 m Ci/g for thin targets(radius 1–2 mm,thickness 1 cm) and for a γ-beam flux of 10^(11) s ~1. Based on these results, the ELI-NP could provide great potential for the production of some innovative radioisotopes of medical interest in sufficient quantities suitable for nuclear medicine research.
基金supported by the National Natural Science Foundation of China(Nos.11405083 and 11675075)the Young Talent Project of the University of South Chinathe Extreme Light Infrastructure-Nuclear Physics(ELI-NP)-Phase I,a project co-financed by the European Union through the European Regional Development Fund
文摘For simulating more accurately neutron or proton production from photonuclear reactions,a data-based photonuclear reaction simulation algorithm has been developed.Reliable photonuclear cross sections from evaluated or experimental database are chosen as input data.For checking the validity of the use of the data-based photonuclear algorithm,benchmarking simulations are presented in detail.We calculate photonuclear cross sections or reaction yield for ~9Be,^(48)Ti,^(133)Cs,and ^(197)Au and compare them with experimental data in the region of incident photon energy below ~30 MeV.While Geant4 can hardly reproduce photonuclear experimental data,results obtained from the data-based photonuclear algorithm are found in good agreement with experimental measurements.Potential application in estimation of specific activity of radioisotopes is further discussed.We conclude that the developed data-based photonuclear algorithm is suitable for an accurate prediction of photoninduced neutron or proton productions.
文摘The interaction of micro-bubbles with ultra-intense laser pulses has been shown to generate ultra-high proton densities and correspondingly high electric fields.Weinvestigate the possibility of using such a combination to study the fundamental physical phenomenon of vacuum polarization.With current or near-future laser systems,measurement of vacuum polarization via the bending of gamma rays that pass near imploded microbubbles may be possible.Since it is independent of photon energy to within the leading-order solution of the Heisenberg–Euler Lagrangian and the geometric optics approximation,the corresponding index of refraction can dominate the indices of refraction due to other effects at sufficiently high photon energies.We consider the possibility of its application to a transient gamma-ray lens.
文摘Heavy-ion fusion reactions between light nuclei such as carbon and oxygen isotopes have been studied becauseof their importance in a wide variety of stellar burning scenarios. However, due to extremely low cross sectionsand signal/background ratio, all the measurements could only be carried out at energies well above the regionof astrophysical interest. The reaction rates in stellar environment could be estimated only by extrapolating theexisted cross sections or the astrophysical S-factors at higher energies. The situation is even more complicated bythe strong, relatively narrow resonances in some reactions, such as 12C+12C, 12C+16O. Traditionally, optical modelor equivalent square-well optical model (ESW) were used to fit the average cross section and predict the reactioncross sections at the energies of astrophysical interest[1]. Recently, a new model, the hindrance model, was proposedto provide systematic fits to fusion reaction data at extreme sub-barrier energies[2]. Lacking of experimental datawithin this energy range, large discrepancies exist among different nuclear reaction models.
基金funding from the European Union’s Horizon 2020 research and innovation programme through the European IMPULSE project under grant agreement No.871161 and LASERLAB-EUROPE V under grant agreement No.871124from grant PDC2021-120933-I00 funded by MCIN/AEI/10.13039/501100011033 and by the European Union Next Generation EU/PRTR+4 种基金from grant PID2021-125389OA-I00 funded by MCIN/AEI/10.13039/501100011033/FEDER,UE and by‘ERDF A way of making Europe’by the European Union and in addition to Unidad de Investigacion Consolidada de la Junta de Castilla y Leon No.CLP087U16The UPM47 campaign was funded through IOSIN,Nucleu PN-IFIN-HH 23-26 Code PN 2321the ELI-NP Phase II,a project co-financed by the Romanian Government and the European Union through the European Regional Development Fund and the Competitiveness Operational Programme(1/07.07.2016,COP,ID 1334)This research was funded,in part,by the French Agence Nationale de la Recherche(ANR),Project No.ANR-22-CE30-0044supported by the Ministry of Youth and Sports of the Czech Republic(Project Nos.LM2023068 and LM2018114(PALS RI)).
文摘We present a novel scheme for rapid quantitative analysis of debris generated during experiments with solid targets following relativistic laser–plasma interaction at high-power laser facilities.Results are supported by standard analysis techniques.Experimental data indicate that predictions by available modelling for non-mass-limited targets are reasonable,with debris of the order of hundreds ofμg per shot.We detect for the first time two clearly distinct types of debris emitted from the same interaction.A fraction of the debris is ejected directionally,following the target normal(rear and interaction side).The directional debris ejection towards the interaction side is larger than on the side of the target rear.The second type of debris is characterized by a more spherically uniform ejection,albeit with a small asymmetry that favours ejection towards the target rear side.
基金supported by the PN 23 21 01 05 and the LASCOMB ELI-Ro contracts funded by the Romanian Ministry of Research, Innovation and Digitalization and the IOSIN 2023 funds for research infrastructures of national interest
文摘We are showing a significant enhancement in the temporal contrast by reducing the coherent noise of the 10 PW laser system at the Extreme Light Infrastructure-Nuclear Physics facility. The temporal contrast was improved by four orders of magnitude at 10 picoseconds and by more than one order of magnitude at 50 picoseconds before the main peak. This improvement of the picosecond contrast is critical for the experiments using thin solid targets.
基金This work was supported by the Romanian Ministry of Education and Research,under Nucleus Project LAPLAS VII contract No.30N/2023,ELI RO 2020-12,PCE 104/2022,PED 580/2022We would also like to acknowledge the support from project code PN 2321 sponsored by the Romanian Ministry of Research,Innovation,and Digitalisation by the Nucleus program.Financial support of the ASUR platform was provided by the European Community and LaserLab Europe programs EU-H2020654148 and 871124(projects Nos.CNRS-LP3002460 and CNRS-LP3002589).
文摘With ultrafast laser systems reaching presently 10 PW peak power or operating at high repetition rates,research towards ensuring the long-term,trouble-free performance of all laser-exposed optical components is critical.Our work is focused on providing insight into the optical material behavior at fluences below the standardized laser-induced damage threshold(LIDT)value by implementing a simultaneous dual analysis of surface emitted particles using a Langmuir probe(LP)and the target current(TC).HfO_(2) and ZrO_(2) thin films deposited on fused silica substrates by pulsed laser deposition at various O_(2) pressures for defect and stoichiometry control were irradiated by Gaussian,ultrashort laser pulses(800 nm,10 Hz,70 fs)in a wide range of fluences.Both TC and LP collected signals were in good agreement with the existing theoretical description of laser–matter interaction at an ultrashort time scale.Our approach for an in situ LIDT monitoring system provides measurable signals for below-threshold irradiation conditions that indicate the endurance limit of the optical surfaces in the single-shot energy scanning mode.The LIDT value extracted from the LP-TC system is in line with the multipulse statistical analysis done with ISO 21254-2:2011(E).The implementation of the LP and TC as on-shot diagnostic tools for optical components will have a significant impact on the reliability of next-generation ultrafast and high-power laser systems.
基金Extreme Light Infrastructure Nuclear Physics (ELI-NP)Phase Ⅱ,is a project co-financed by the Romanian Government and the European Union through the European Regional Development Fund and the Competitiveness Operational Programme (1/07.07.2016, COP, ID 1334)the support contract sponsored by the Romanian Ministry of Research and Innovation:PN 19 0601 05
文摘We report on the generation and delivery of 10.2 PW peak power laser pulses,using the High Power Laser System at the Extreme Laser Infrastructure–Nuclear Physics facility.In this work we demonstrate for the first time,to the best of our knowledge,the compression and propagation of full energy,full aperture,laser pulses that reach a power level of more than 10 PW.
基金Supported by the following projects:Proiect IDEI(56/07.10.2011)the IFA project Romania-CERN(7/16.03.2016)(LHCb-Ro)
文摘In this paper we present a comparative study between PYTHIA, EPOS, QGSJET, and SIBYLL generators. The global event observables considered are the charged energy flow, charged particle distributions, charged hadron production ratios and V^0 ratios. The study is performed in the LHCb and TOTEM fiducial phase spaces on minimum bias simulated data samples for pp collisions at = 7 TeV , using the reference measurements from these experiments. In the majority of cases, the measurements are within a band defined by the most extreme predictions. The observed differences between the predictions and the measurements seem to be, in most part, caused by extrapolation from the central pseudorapidity region (|η| 2.5), in which the generators were mainly tuned.
基金the support in this work provided through the project SBUF (ELI-RO 16/2020)
文摘Spectral-broadening of the APOLLON PW-class laser pulses using a thin-film compression technique within the longfocal-area interaction chamber of the APOLLON laser facility is reported,demonstrating the delivery of the full energy pulse to the target interaction area.The laser pulse at 7 J passing through large aperture,thin glass wafers is spectrally broadened to a bandwidth that is compatible with a 15-fs pulse,indicating also the possibility to achieve sub-10-fs pulses using 14 J.Placing the post-compressor near the interaction makes for an economical method to produce the shortest pulses by limiting the need for high damage,broadband optics close to the final target rather than throughout the entire laser transport system.
基金This work was supported by the Center of Excellence‘Center of Photonics’,Ministry of Science and Higher Education of the Russian Federation(contract No.075-15-2020-906)Project ELI-RO 16/2020 SBUF funded by the Institute for Atomic Physics(IFA)and by the Council for Doctoral Studies(CSUD),University of Bucharest.
文摘The post-compression technique based on self-phase modulation of high-energy pulses leads to an increase in achievable peak power and intensity.Typically,the pulses considered in experiments have been less than 100 fs in duration.Here,the method is applied to the ELFIE laser system at the LULI facility,for a pulse of 7 J energy and an initial measured duration of 350 fs.A 5-mm-thick fused silica window and a 2 mm cyclic-olefin polymer were used as optical nonlinear materials.The 9 cm diameter beam was spectrally broadened to a bandwidth corresponding to 124 fs Fourier-limited pulse duration,and then it was partly post-compressed to 200 fs.After measuring the spatial spectra of the beam fluence,a uniform gain factor of 4 increase in the fluctuations over the studied range of frequencies is observed,due to small-scale self-focusing.
基金support from the European Cluster of Advanced Laser Light Sources(EUCALL)project which has received funding from the European Union’s Horizon 2020 research and innovation programme under agreement No 654220support of the ELI-NP team and from ELI-NP PhaseⅡ,a project co-financed by the Romanian Government and European Union through the European Regional Development Fund–the Competitiveness Operational Programme(1/07.07.2016,COP,ID 1334)+5 种基金support of the ELI-Beamlines project,mainly sponsored by the project ELI–Extreme Light Infrastructure–Phase 2(CZ.02.1.01/0.0/0.0/15–008/0000162)through the European Regional Development Fundsupport of Planet Dive,a project that has received funding from the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(grant agreement N.637748)supported by the Helmholtz Association under VHNG-1141support of the European Research Council Consolidator Grant ENSURE(ERC-2014CoG No.647554)Support by the Nanofabrication Facilities Rossendorfthe Institute of Ion Beam Physics and Materials Research,HZDR
文摘A number of laser facilities coming online all over the world promise the capability of high-power laser experiments with shot repetition rates between 1 and 10 Hz. Target availability and technical issues related to the interaction environment could become a bottleneck for the exploitation of such facilities. In this paper, we report on target needs for three different classes of experiments: dynamic compression physics, electron transport and isochoric heating, and laser-driven particle and radiation sources. We also review some of the most challenging issues in target fabrication and high repetition rate operation. Finally, we discuss current target supply strategies and future perspectives to establish a sustainable target provision infrastructure for advanced laser facilities.
文摘True ternary fission and Tin-accompanied ternary fission of 242Pu are studied by using the'Three Cluster Model'.True ternary fission is considered as a formation of heavy fragments in the region 28≤Z1,Z2,Z3≤38 with comparable masses.The possible fission channels are predicted by the potential-energy calculations.Interaction potentials,Q-values and relative yields for all possible fragmentations in equatorial and collinear configurations are calculated and compared.It is found that ternary fission with formation of a double magic nucleus like 132Sn is more probable than the other fragmentations.Also,the kinetic energies of the fragments for the group Z1=32,Z2=32 and Z3=30 are calculated for all combinations in the collinear geometry as a sequential decay.
基金Helmholtz International Center for FAIR(HIC for FAIR)Helmholtz Association(IK-RU-002)+5 种基金Russian Ministry of Education and Science(NSh-932.2014.2)Russian Foundation for Basic Research(14-02-00090-a)Polish National Science Center(UMO-2011/01/B/ST2/01943)Polish Ministry of Science and Higher Education(0079/DIA/2014/43,Grant Diamentowy)Helmholtz-CAS Joint Research Group(HCJRG-108)FPA2009-08848 contract(MICINN,Spain)
文摘An experiment aimed to investigate the two-proton(2p) decay of the previously unknown nucleus ^(30)Ar was performed at GSI. By tracking the decay products in-flight with silicon micro-strip detectors, the 2p decays of ^(30)Ar were observed for the first time. For the calibration purpose, 2p decays of ^(19)Mg were also remeasured by tracking the coincident ^(17)Ne+p+p trajectories. By comparing the measured angular p-17 Ne correlations with those obtained from the corresponding Monte Carlo simulations,the simultaneous 2p decay of ^(19)Mg ground state and the sequential 2p emission of several known excited states of ^(19)Mg were confirmed. One new excited state in ^(19)Mg and two new excited states in ^(18)Na were observed.
基金funded through IOSIN,Nucleu PN-IFIN-HH 23-26 Code PN 2321Extreme Light Infrastructure-Nuclear Physics(ELI-NP)Phase II+2 种基金a project co-financed by the Romanian Government and the European Union through the European Regional Development Fund and the Competitiveness Operational Programme(1/07.07.2016,COP,ID 1334)through IFA project ELI-RO 03/2020 Pulse-Mereadreceived funding from the European Union’s HORIZON-INFRA-2022-TECH-01 call under grant agreement number 101095207
文摘The spatial distribution of beams with orbital angular momentum in the far field is known to be extremely sensitive to angular aberrations,such as astigmatism,coma and trefoil.This poses a challenge for conventional beam optimization strategies when a homogeneous ring intensity is required for an application.We developed a novel approach for estimating the Zernike coefficients of low-order angular aberrations in the near field based solely on the analysis of the ring deformations in the far field.A fast,iterative reconstruction of the focal ring recreates the deformations and provides insight into the wavefront deformations in the near field without relying on conventional phase retrieval approaches.The output of our algorithm can be used to optimize the focal ring,as demonstrated experimentally at the 100 TW beamline at the Extreme Light Infrastructure-Nuclear Physics facility.
文摘The future experimental campaign with the SAMURAI setup at RIKEN will explore a wide range of neutron-deficient nuclei with a particular focus on the most critical(p, γ) reaction rates relevant to the astrophysical rp-process in type-I X-ray bursts(XRB). Intense radioactive-ion(RI) beams at an energy of a few hundred Me V/nucleon will be deployed to populate proton-unbound states in the nuclei of interest through the Coulomb excitation or nucleon-removal processes. The decay of these states into a proton and a heavy residue will be measured using complete kinematics and the information about time reversal proton-capture process will be obtained. This method will provide the vital experimental data on the resonances, which dominate the stellar(p, γ) reaction rates, as well as on the direct proton-capture process for some other cases. The experimental setup will utilize for the first time the High-Resolution90?-mode of the SAMURAI spectrometer in combination with the existing detection systems, including custom-designed Si-strip detectors for simultaneous detection and tracking of heavy ions and protons emitted from the target. The details of the experimental method and the utilized apparatus are discussed in this paper.
基金Polish National Science Center(UMO2011/01/B/ST2/01943)RFBR(14-02-00090)+1 种基金Polish Ministry of Science and Higher Education(0079/DIA/2014/43)Helmholtz International Center for FAIR
文摘The β^+ decay of ^(31)Ar was investigated in an experiment at the GSI-FRS spectrometer.The ions of interest have been produced in the fragmentation of a ^(36)Ar beam at 880 Me V/nucleon and implanted in a time projection chamber with optical readout. In addition to β-delayed one and two proton emission, for the first time the emission of β-delayed 3 protons has been observed. The branching ratio for this decay mode is found to be(0.07 ± 0.02)%.
