Fast neutron flux measurements with high count rates and high time resolution have important applications in equipment such as *** this study,real-time neutron and gamma discrimination was implemented on a self-develo...
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Fast neutron flux measurements with high count rates and high time resolution have important applications in equipment such as *** this study,real-time neutron and gamma discrimination was implemented on a self-developed 500-Msps,12-bit digitizer,and the neutron and gamma spectra were calculated directly on an FPGA.A fast neutron flux measurement system with BC-501A and EJ-309 liquid scintillator detectors was developed and a fast neutron measurement experiment was successfully performed on the HL-2 M tokamak at the Southwestern Institute of physics,*** experimental results demonstrated that the system obtained the neutron and gamma spectra with a time accuracy of 1 *** count rates of up to 1 Mcps,the figure of merit was greater than 1.05 for energies between 50 keV and 2.8 MeV.
A novel scheme to suppress both stimulated Brillouin scattering(SBS) and stimulated Raman scattering(SRS) by combining an alternating frequency(AF) laser and a transverse magnetic field is proposed. The AF laser allow...
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A novel scheme to suppress both stimulated Brillouin scattering(SBS) and stimulated Raman scattering(SRS) by combining an alternating frequency(AF) laser and a transverse magnetic field is proposed. The AF laser allows the laser frequency to change discretely and alternately over time. The suppression of SBS is significant as long as the AF difference is greater than the linear growth rate of SBS or the alternating time of the laser frequency is shorter than the linear growth time of SBS. However, the AF laser proves ineffective in suppressing SRS, which usually has a much higher linear growth rate than SBS. To remedy that, a transverse magnetic field is included to suppress the SRS instability. The electrons trapped in the electron plasma waves(EPWs) of SRS can be accelerated by the surfatron mechanism in a transverse magnetic field and eventually detrapped. While continuously extracting energy from EPWs, the EPWs are dissipated and the kinetic inflation of SRS is suppressed. The one-dimensional particle-in-cell simulation results show that both SBS and SRS can be effectively suppressed by combining the AF laser with a transverse magnetic field with tens of Tesla. The total reflectivity can be dramatically reduced by more than one order of magnitude. These results provide a potential reference for controlling SBS and SRS under the related parameters of inertial confinement fusion.
Effective adjustment and control of the oxidation state of plutonium(Pu)and neptunium(Np)is an indispensable component of Np/Pu separation in spent nuclear fuel *** hydrazine derivatives including methylhydrazine(CH_(...
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Effective adjustment and control of the oxidation state of plutonium(Pu)and neptunium(Np)is an indispensable component of Np/Pu separation in spent nuclear fuel *** hydrazine derivatives including methylhydrazine(CH_(3)N_(2)H_(3))effectively achieves the reduction of Np(Ⅵ)to Np(V)without reducing Pu(Ⅳ).Herein,we explored the reduction mechanisms of Pu(Ⅳ)and Np(Ⅵ)by CH_(3)N_(2)H_(3)in HNO_(3)solution using scalar-relativistic density functional *** elucidated the difference in the reduction mechanism between Np(Ⅵ)and Pu(Ⅳ)ions by CH_(3)N_(2)H_(3).The energy barrier for the reduction of[NpⅥO_(2)(H_(2)O)_(5)]^(2+)and[NpⅥO_(2)(NO_(3))(H_(2)O)_(3)]^(+)by CH_(3)N_(2)H_(3)is largely different due to the coordination of nitrate ***,the energy barrier of the reduction of[NpⅥO_(2)(H_(2)O)_(5)]^(2+)is apparently lower than that of[PuⅣ(NO_(3))_(2)(H_(2)O)_(7)]^(2+),which is in line with the experimental *** results of Mayer bond order and localized molecular orbitals clarify the structural evolution of the reaction *** of the spin density demonstrates that the first Np(Ⅵ)and Pu(Ⅳ)reduction belongs to the outer-sphere electron transfer and the second Np(Ⅵ)and Pu(Ⅳ)reduction is the hydrogen *** study explains theoretically why CH_(3)N_(2)H_(3)reduces Np(Ⅵ)but not Pu(Ⅳ),and helps to design promising reductants for the Np/Pu separation in spent nuclear fuel reprocessing.
A relatively new branch of science-nuclear forensics,aiming at providing the nature,origin,history and possible trafficking route of seized nuclear materials/devices,has been established and rapidly developed over dec...
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A relatively new branch of science-nuclear forensics,aiming at providing the nature,origin,history and possible trafficking route of seized nuclear materials/devices,has been established and rapidly developed over decades to screen illicit nuclear *** highly interdisciplinary science is built upon a foundation of analytical chemistry,radiochemistry,nuclearphysics,material sciences,geology,and other scientific disciplines,within which radiochemical methodologies and radioanalytical techniques play a key *** present review provides a brief overview about the crucial aspects of nuclear forensics,including basic content,procedure,concerned elements,common separation,analytical method,and so *** state of the art and recent progresses of nuclear forensics by research communities in China are reviewed,while selected examples and practical applications are *** challenges associated with this new area and on-going developments are highlighted and discussed.
The phenomenon of sunbathing in the morning is almost ubiquitous in residential areas across Indonesia, following the "New Normal"after the Covid-19 pandemic. The local government even encourages its citizen...
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A dedicated weak current measurement system was designed to measure the weak currents generated by the neutron ionization *** system incorporates a second-order low-pass filter circuit and the Kalman filtering algorit...
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A dedicated weak current measurement system was designed to measure the weak currents generated by the neutron ionization *** system incorporates a second-order low-pass filter circuit and the Kalman filtering algorithm to effectively filter out noise and minimize interference in the measurement *** conducted under normal temperature conditions has demonstrated the system's high precision ***,it was observed that temperature variations can affect the measurement *** were collected across temperatures ranging from -20 to 70℃,and a temperature correction model was established through linear regression fitting to address this *** feasibility of the temperature correction model was confirmed at temperatures of -5 and 40℃,where relative errors remained below 0.1% after applying the temperature *** research indicates that the designed measurement system exhibits excellent temperature adaptability and high precision,making it particularly suitable for measuring weak currents.
The ground vector Bc*meson has not yet been experimentally discovered until *** the dominant electromagnetic decays,nonleptonic weak decays provide another choice to search for the mysterious Bc**** by the potential p...
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The ground vector Bc*meson has not yet been experimentally discovered until *** the dominant electromagnetic decays,nonleptonic weak decays provide another choice to search for the mysterious Bc**** by the potential prospects of Bc*mesons in future high-luminosity colliders,nonleptonic Bc*weak decays induced by bottom and charm quark decays are studied within the SM by using a naive factorization *** is found that for Bc*→Bs,dπ,Bs,d*π,Bs,dρ,BsK,Bs*K,BsK*,ηc(1S,2S)π,ηc(1S,2S)ρandψ(1S,2S)πdecays,a few hundred and even thousands of events might be observable in CEPC,FCC-ee and LHCb@HL-LHC experiments.
Single-walled carbon nanotubes(SWNTs)have been regarded as one of the most promising candidates to supplement or even replace silicon in the post-Moore *** requirement is to prepare the horizontally aligned SWNTs arra...
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Single-walled carbon nanotubes(SWNTs)have been regarded as one of the most promising candidates to supplement or even replace silicon in the post-Moore *** requirement is to prepare the horizontally aligned SWNTs arrays(HASAs)with multiple indicators,including high density,high semiconducting purity,and wafer-scale ***,after all the fevered works being done in controlled synthesis,we still have a long way to go before realizing the application of SWNTs in highly performed electronic *** methods of batch production and high-throughput characterization techniques of the HASAs are the two main *** this outlook,we first summarized the progresses in synthesis of HASAs with either high density or high semiconducting *** the methods adopted in characterizing SWNTs and HASAs were discussed according to the different principles of characterization ***,the development of carbon nanotube based electronic devices,specifically,the field effect transistors(FETs),was reviewed from three *** problems involved in electronic applications bring forward the higher request to the HASAs ***,in the end of this outlook,we prospected the future of the synthesis and corresponding characterization of HASAs,and tried to provide our ideas about how to pave the way to the batch production of HASAs for carbon based electronic devices.
Based on Ginzburg-Landau theory,we investigate the electromagnetic properties of two-band superconductors with broken time-reversal *** propose an apparatus of a superconducting ring integrated with a microbridge stru...
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Based on Ginzburg-Landau theory,we investigate the electromagnetic properties of two-band superconductors with broken time-reversal *** propose an apparatus of a superconducting ring integrated with a microbridge structure to probe the peculiar topological excitations in the chiral *** phase difference of two order parameters in the superconductor satisfies the double sine-Gordon equation,and a linear relationship between the phase difference at the two ends of the junction and the total magnetic flux in the ring can be *** with the Josephson current-phase relation,we establish the dependence of the circulating current and magnetic flux on the applied external magnetic *** results show that this single-junction system will exhibit the irreversible behaviors and two different types of fractional flux transitions can clearly manifest the time-reversal symmetry breaking in two-component superconductors.
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