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nuclear Science and Techniques 2024年第1期35卷 145-154页

作者： M.Hajipour G.R.Ansarifar department of nuclear Engineering Faculty of PhysicsUniversity of IsfahanIsfahan 81746-73441Iran

nuclear power plants exhibit non-linear and time-variable ***,designing a control system that sets the reactor power and forces it to follow the desired load is complicated.A supercritical water reactor(SCWR)is a fourth-generation conceptual *** an SCWR,the non-linear dynamics of the reactor require a controller capable of control-ling the *** this study,a pressure-tube-type SCWR was controlled during reactor power maneuvering with a higher order sliding mode,and the reactor outgoing steam temperature and pressure were controlled *** an SCWR,the temperature,pressure,and power must be maintained at a setpoint(desired value)during power *** point kinetics equations with three groups of delayed neutrons were used in the ***-order and classic sliding mode controllers were separately manufactured to control the plant and were compared with the PI controllers speci-fied in previous *** controlled parameters were reactor power,steam temperature,and ***,for these parameters,the PI controller had certain instabilities in the presence of *** classic sliding mode controller had a higher accuracy and stability;however its main drawback was the chattering *** was highly accurate and stable and had a small computational *** reality,it followed the desired values without oscillations and chattering.

关键词： Supercritical water nuclear reactor Higher order sliding mode controller Steam temperature Steam pressure Point kinetics model

A polarized^(3)He system based on metastability-exchange optical pumping

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Science China(physics,Mechanics & Astronomy) 2024年第7期67卷 72-81页

作者： Yuting Wang Liangyong Wu Kaiyuan Zhang Mei Peng Siyu Chen Haiyang Yan State Key Laboratory of nuclear physics and Technology School of PhysicsPeking UniversityBeijing 100871China Institute of nuclear physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China Key Laboratory of nuclear physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200433China Key Laboratory of Neutron physics Institute of Nuclear Physics and ChemistryChina Academy of Engineering PhysicsMianyang 621900China

Hyperpolarized^(3)He nuclei have emerged as a significantly important approach in quantum precision measurement techniques,with extensive applications in fundamental physics,magnetometry,metrology,and *** this study,we report on the design and implementation of a^(3)He polarization system at the China Mianyang Research Reactor(CMRR),utilizing the metastabilityexchange optical pumping(MEOP)*** employed a Merritt coil system consisting of four square coils to furnish a uniform holding *** deployed a 2 W fiber laser to pump the metastable^(3)He atoms and conducted free induction decay(FID)detection of the polarized^(3)He nuclei using both pickup coil and optical *** the optical method,we used a50 m W linearly polarized distributed Bragg reflector(DBR)laser as the *** applied transverse light absorption polarimetry to measure the absolute nuclear polarization of the ground-state^(3)*** have developed cell fabrication capabilities at the CMRR,and cells at various pressures ranging from 100 to 1000 Pa have been fabricated and *** a typical borosilicate cell with 100 Pa pressure,the absolute polarization is measured as Pn≈70%,and the transverse relaxation time is estimated as T2≈0.5 ***,we constructed a few aluminosilicate cells,each carefully filled with pure^(3)He at a pressure of 100 ***,we conducted a comprehensive evaluation of their performance in the context of MEOP.

关键词： metastability exchange optical pumping polarized^(3)He magnetic resonance

Principal components of nuclear mass models

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Science China(physics,Mechanics & Astronomy) 2024年第7期67卷 65-71页

作者： Xin-Hui Wu Pengwei Zhao department of physics Fuzhou UniversityFuzhou 350108China State Key Laboratory of nuclear physics and Technology School of PhysicsPeking UniversityBeijing 100871China

Principal component analysis(PCA)is employed to extract the principal components(PCs)present in nuclear mass models for the first *** effects from different nuclear mass models are reintegrated and reorganized in the extracted *** PCs are recombined to build new mass models,which achieve better accuracy than the original theoretical mass *** comparison indicates that using the PCA approach,the effects contained in different mass models can be collaborated to improve nuclear mass predictions.

关键词： nuclear mass principal component analysis nuclear models statistical methods

Structure and 2p decay mechanism of^(18)Mg

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nuclear Science and Techniques 2024年第6期35卷 145-154页

作者： Long Zhou De-Qing Fang Si-Min Wang Hui Hua Key Laboratory of nuclear physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical nuclear physics NSFC and Fudan UniversityShanghai 200438China School of physics and State Key Laboratory of nuclear physics and Technology Peking UniversityBeijing 100871China

The recently discovered,extremely proton-rich nuclide 18 Mg exhibits ground-state decay via two sequential two-proton(2p)emissions through the intermediate nucleus,*** study investigates the structure and the initial 2p decay mechanism of^(18)Mgby examining the density and correlations of the valence protons using a three-body Gamow coupled-channel *** results show that the ground state of^(18)Mgis significantly influenced by the continuum,resulting in a significant s-wave ***,based on the current framework,this does not lead to a significant deviation in mirror symmetry in either the structure or spectroscopy of the 18Mg-18C ***,the time evolution analysis of the^(18)Mgground state suggests a simultaneous 2p emission during the first step of *** observed nucleon-nucleon correlations align with those of the light-mass 2p emitters,indicating a consistent decay behavior within this nuclear region.

关键词： Structure of^(18)Mg Two-proton decay Proton-proton correlation

Electromagnetic fields in ultra-peripheral relativistic heavy-ion collisions

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nuclear Science and Techniques 2024年第2期35卷 103-109页

作者： Jie Zhao Jin-Hui Chen Xu-Guang Huang Yu-Gang Ma Key Laboratory of nuclear physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical nuclear physics NSFC and Fudan UniversityShanghai 200438China physics department and Center for Particle physics and Field Theory Fudan UniversityShanghai 200438China

Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic *** these collisions,highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon *** exchange of photons can induce photonuclear and two-photon interactions and excite *** excitation of the ions results in Coulomb dissociation with the emission of photons,neutrons,and other ***,the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ***,the two colliding ions experience an electromagnetic force that pushes them in opposite directions,causing a back-to-back correlation in the emitted *** a Monte Carlo simulation,we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs,which would provide a clear means to study strong electromagnetic fields and their effects.

关键词： Electromagnetic fields Neutrons Ultra-peripheral relativistic heavy-ion collisions(UPC)

Quantitative method to predict the energetics of helium-nanocavities interactions in metal systems based on electrophobic interaction

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Journal of Materiomics 2024年第3期10卷 725-737页

作者： Fengping Luo Bowen Zhang Zhiying Gao Jia Huang Hong-Bo Zhou Guang-Hong Lu Fei Gao Yugang Wang Chenxu Wang State Key Laboratory of nuclear physics and Technology Center for Applied Physics and TechnologyPeking UniversityBeijing100871China department of physics Beihang UniversityBeijing100191China department of nuclear Engineering and Radiological Science University of MichiganAnn ArborMI48109USA

Energetics of helium-nanocavities interactions are crucial for unveiling underlying mechanisms of nanocavity evolution in nuclear ***,it becomes intractable and even not feasible to obtain these energetics via atomic simulations with increasing nanocavity size and increasing helium content in ***,a universal scaling law of helium-induced interaction energies in nanocavities in metal systems is proposed based on electrophobic interaction of *** on this scaling law and ab-initio calculations,a predictive method for binding energies of helium and displacement defects to nanocavities of arbitrary sizes and with different helium/vacancy ratios is established for BCC iron as a representative and validated by atomic *** predictive method reveals that the critical helium/vacancy ratio for helium-enhanced vacancy binding to nanocavities in-creases with increasing nanocavity size,and the helium/vacancy ratio giving the highest stability of nanocavities is about *** Ostwald ripening of nanocavities is delayed by helium to higher temper-atures due to reduced vacancy de-trapping rates from *** proposed scaling law can be generalized to many metal systems studied in the nuclear materials *** readily coupled into mesoscale models of irradiation damages,this predictive method facilitates clarifying helium role in cavity swelling of metallic nuclear materials.

关键词： Nanocavities Helium Electrophobic interaction Predictive method

Production and test of sPHENIX W/SciFiber electromagnetic calorimeter blocks in China

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nuclear Science and Techniques 2024年第8期35卷 167-176页

作者： Xiao‑Zhou Yu Xi‑Yang Wang Wei‑Hu Ma Shi‑Hong Fu Peng‑Fei Sun Jin‑Xing Song Wan‑Bing He Yang Shen Long Ma Jin‑Hui Chen Huan‑Zhong Huang Si‑Guang Wang Jing Zhou Xiao‑Mei Li Institute of Modern physics Fudan UniversityShanghai 200433China Key Laboratory of nuclear physics and Ion‑Beam Application(MOE) Fudan UniversityShanghai 200433China Science and Technology on nuclear Data Laboratory China Institute of Atomic EnergyBeijing 102413China department of physics and Astronomy University of CaliforniaLos AngelesCA 90095USA State Key Laboratory of nuclear physics and Technology School of PhysicsPeking UniversityBeijing 100871China

The sPHENIX experiment is a new generation of large acceptance detectors at the relativistic heavy ion collider at Brookhaven National Laboratory,with scientific goals focusing on probing the strongly interacting Quark–Gluon plasma with hard probes of jets,open heavy flavor particles,andγ*** EMCal detector,which covers the pseudo-rapidity region of|η|≤1.1,is an essential subsystem of *** this study,we focused on producing and testing EMCal blocks covering a pseudo-rapidity of|η|∈[0.8,1.1].These,in conjunction with the central pseudo-rapidity EMCal blocks,significantly enhance the sPHENIX physics capability of the jet andγparticle *** this paper,the detector module production and testing of sPHENIX W-powder/scintillating fiber(W/ScFi)electromagnetic calorimeter blocks are *** selection of the tungsten powder,mold fabrication,QA procedures,and cosmic ray test results are discussed.

关键词： sPHENIX Tungsten/scintillating fiber electromagnetic calorimeter Cosmic ray test

Comprehensive analysis of uncertainty quantification for the^(58)Ni(n,p)^(58)Co reaction cross section

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Chinese physics C 2024年第9期48卷 170-175页

作者： Mahesh Choudhary Aman Sharma Namrata Singh Mahima Upadhyay Punit Dubey A.Gandhi Akash Hingu G Mishra Sukanya De L.S.Danu Ajay Kumar R.G.Thomas Saurav Sood Sajin Prasad S.Mukherjee I.N.Ruskov Yu.N.Kopatch A.Kumar department of physics Banaras Hindu UniversityVaranasi 221005India Horia Hulubei National Institute of physics and nuclear Engineering-IFIN-HH Bucharest 077125Romania department of physics The Maharaja Sayajirao University of BarodaVadodara 390002India nuclear physics Division Bhabha Atomic Research CentreMumbai 400085India Health physics Division Bhabha Atomic Research CentreMumbai 400085India department of Electrical Power Engineering Brno University of TechnologyBrno 61600Czech Republic Institute for nuclear Research and nuclear Energy Bulgarian Academy of SciencesSofia 1784Bulgaria Joint Institute for nuclear Research(JINR) Dubna 141980Russia

In this study,we measured the^(58)Ni(n,p)^(58)Co reaction cross section with neutron energies of 1.06,1.86,and 2.85 *** cross section was measured using neutron activation techniques andγ-ray spectroscopy,and it was compared with cross section data available in the ***,we calculated the covariance matrix of the measured cross section for the aforementioned nuclear *** uncertainties of the theoretical calculation for^(58)Ni(n,p)^(58)Co reaction cross section were calculated via Monte Carlo *** this study,we used uncertainties in the optical model and level density parameters to calculate uncertainties in the theoretical cross *** theoretical calculations were performed by using *** this study,we aim to analyze the effect of uncertainties of the nuclear model input as well as different experimental variables used to obtain the values of reaction cross section.

关键词： ^(58)Ni(n p)^(58)Co reaction γ-ray spectroscopy uncertainty quantification of cross section covariance analysis

Quantifying the strength of magnetic fields using baryon electric charge correlation

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nuclear Science and Techniques 2024年第8期35卷 5-8页

作者： Xu‑Guang Huang physics department and Center for Particle physics and Field Theory Fudan UniversityShanghai 200433China Key Laboratory of nuclear physics and Ion‑beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical nuclear physics National Natural Science Foundation of China and Fudan UniversityShanghai 200438China

Although heavy-ion collisions generate strong magnetic fields,their direct measurement is a challenging task.A new observable,the baryon electric charge correlation,was recently found to be sensitive to the magnetic field strength and thus could be used as a magnetometer for heavy-ion ***,this observable may shed light on the equation of state and phase structure of quantum chromodynamics(QCD)under magnetic *** and understanding the phase structure of quantum chromodynamics(QCD)is important in contemporary physics[1].

关键词： charge observable magnetic

Construction and performance test of charged particle detector array for MATE

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nuclear Science and Techniques 2024年第8期35卷 92-100页

作者： Xiao‑Bin Li Long‑Hui Ru Zhi‑Chao Zhang Bing‑Feng Lv Ning‑Tao Zhang Jin‑Long Zhang Chen‑Gui Lu Bing‑Shui Gao Jun‑Bing Ma Fu‑Shuai Shi Satoru Terashima Xiao‑Dong Xu Zhen Bai Shi‑Wei Xu Yan‑Yun Yang Hooi‑Jin Ong Xiao‑Dong Tang Institute of Modern physics(IMP) Chinese Academy of SciencesLanzhou 730000China School of nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Research Center for nuclear physics Osaka UniversityIbarakiOsaka 567‑0047Japan RIKEN Nishina Center WakoSaitama 351‑0198Japan Joint department for nuclear physics Lanzhou University and Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China

A charged particle array named MATE-PA,which serves as an auxiliary detector system for a Multi-purpose Active-target Time projection chamber used in nuclear astrophysical and exotic beam Experiments(MATE),was *** array comprised of 20 single-sided strip-silicon detectors covering approximately 10%of the solid *** detectors facilitated the detection of reaction-induced charged particles that penetrate the active volume of the *** performance of MATE-PA has been experimentally studied using an alpha source and a 36-MeV 14 N beam injected into the MATE chamber on the radioactive ion beam line in Lanzhou(RIBLL).The chamber was filled with a gas mixture of 95%4 He and 5%CO_(2) at a pressure of 500 *** results indicated good separation of light-charged particles using the forward double-layer silicon detectors of *** energy resolution of the Si detectors was deduced to be approximately 1%(σ)for an energy loss of approximately 10 MeV caused by theα*** inclusion of MATE-PA improves particle identification and increases the dynamic range of the kinetic energy of charged particles,particularly that of theαparticles,up to approximately 15 MeV.

关键词： Silicon detector array Active target Time projection chamber