Current investigation deals with the effect of grain growth process as a function of sintering temperature on the electromagnetic properties （initial permeability, impedance, and gain） of Mn-Zn ferrite （MZF） cores...Current investigation deals with the effect of grain growth process as a function of sintering temperature on the electromagnetic properties （initial permeability, impedance, and gain） of Mn-Zn ferrite （MZF） cores （toroids）. By employing auto combustion process, nanosized [（20 ± 5） nm] MZF powders were synthesized and toroid shape cores were obtained after subsequent calcination and firing （sintering） process. It was observed that the submicron structure （0.5 μm） achieved in the ferrite core sintered at 1,000 ℃ was gradually transformed into micron size grains by increasing the firing temperature i.e., 1,100, 1,200, and 1,350 ℃. The results reveal that MZF core sintered at low temperature （1,000 ℃） showed high impedance, low initial permeability, and narrow working frequency range i.e., 3-15 MHz. However, the improvement in initial permeability, sintered density, and operational frequency range （100 kHz-17 MHz） was observed at high temperature （1,350 ℃） firing in the inert environment. This synthesized MZF core is more suitable for miniaturized switch mode power supply applications.展开更多
The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neut...The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neutrino measurements,such as its low-energy threshold,high energy resolution compared with water Cherenkov detectors,and much larger target mass compared with previous liquid scintillator detectors.In this paper,we present a comprehensive assessment of JUNO's potential for detecting^8B solar neutrinos via the neutrino-electron elastic scattering process.A reduced 2 MeV threshold for the recoil electron energy is found to be achievable,assuming that the intrinsic radioactive background^(238)U and^(232)Th in the liquid scintillator can be controlled to 10^(-17)g/g.With ten years of data acquisition,approximately 60,000 signal and 30,000 background events are expected.This large sample will enable an examination of the distortion of the recoil electron spectrum that is dominated by the neutrino flavor transformation in the dense solar matter,which will shed new light on the inconsistency between the measured electron spectra and the predictions of the standard three-flavor neutrino oscillation framework.IfDelta m^(2)_(21)=4.8times10^(-5);(7.5times10^(-5))eV^(2),JUNO can provide evidence of neutrino oscillation in the Earth at approximately the 3sigma(2sigma)level by measuring the non-zero signal rate variation with respect to the solar zenith angle.Moreover,JUNO can simultaneously measureDelta m^2_(21)using^8B solar neutrinos to a precision of 20% or better,depending on the central value,and to sub-percent precision using reactor antineutrinos.A comparison of these two measurements from the same detector will help understand the current mild inconsistency between the value of Delta m^2_(21)reported by solar neutrino experiments and the KamLAND experiment.展开更多
文摘Current investigation deals with the effect of grain growth process as a function of sintering temperature on the electromagnetic properties （initial permeability, impedance, and gain） of Mn-Zn ferrite （MZF） cores （toroids）. By employing auto combustion process, nanosized [（20 ± 5） nm] MZF powders were synthesized and toroid shape cores were obtained after subsequent calcination and firing （sintering） process. It was observed that the submicron structure （0.5 μm） achieved in the ferrite core sintered at 1,000 ℃ was gradually transformed into micron size grains by increasing the firing temperature i.e., 1,100, 1,200, and 1,350 ℃. The results reveal that MZF core sintered at low temperature （1,000 ℃） showed high impedance, low initial permeability, and narrow working frequency range i.e., 3-15 MHz. However, the improvement in initial permeability, sintered density, and operational frequency range （100 kHz-17 MHz） was observed at high temperature （1,350 ℃） firing in the inert environment. This synthesized MZF core is more suitable for miniaturized switch mode power supply applications.
基金This work was supported by the Chinese Academy of Sciences,the National Key R&D Program of China,the CAS Center for Excellence in Particle Physics,the Joint Large Scale Scientific Facility Funds of the NSFC and CAS,Wuyi University,and the Tsung-Dao Lee Instiute of Shanghai Jiao Tong University in China,the In stiut National de Physique Nucleaire et de Physique de Particules(IN2P3)in France,the Istituto Nazionale di Fisica Nucleare(INFN)in Italy,the Fond de la Recherche Scintifique(F.R.S-FNRS)and FWO under the"Excellence of Science-EOS"in Belgium,the Conselho Nacional de Desenvolvimento Cientificoce Tecnologico in Brazil,the Agencia Nacional de Investigacion y Desrrollo in Chile,the Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republic,the Deutsche Forschungsgemeinschaft(DFG),the Helmholtz Association,and the Cluster of Exellence PRISMA+in Germany,the Joint Institute of Nuclear Research(JINR),Lomonosov Moscow State University,and Russian Foundation for Basic Research(RFBR)in Russia,the MOST and MOE in Taiwan,the Chu-lalongkorm University and Suranaree University of Technology in Thailand,and the University of aliformia at Irvine in USA.
文摘The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neutrino measurements,such as its low-energy threshold,high energy resolution compared with water Cherenkov detectors,and much larger target mass compared with previous liquid scintillator detectors.In this paper,we present a comprehensive assessment of JUNO's potential for detecting^8B solar neutrinos via the neutrino-electron elastic scattering process.A reduced 2 MeV threshold for the recoil electron energy is found to be achievable,assuming that the intrinsic radioactive background^(238)U and^(232)Th in the liquid scintillator can be controlled to 10^(-17)g/g.With ten years of data acquisition,approximately 60,000 signal and 30,000 background events are expected.This large sample will enable an examination of the distortion of the recoil electron spectrum that is dominated by the neutrino flavor transformation in the dense solar matter,which will shed new light on the inconsistency between the measured electron spectra and the predictions of the standard three-flavor neutrino oscillation framework.IfDelta m^(2)_(21)=4.8times10^(-5);(7.5times10^(-5))eV^(2),JUNO can provide evidence of neutrino oscillation in the Earth at approximately the 3sigma(2sigma)level by measuring the non-zero signal rate variation with respect to the solar zenith angle.Moreover,JUNO can simultaneously measureDelta m^2_(21)using^8B solar neutrinos to a precision of 20% or better,depending on the central value,and to sub-percent precision using reactor antineutrinos.A comparison of these two measurements from the same detector will help understand the current mild inconsistency between the value of Delta m^2_(21)reported by solar neutrino experiments and the KamLAND experiment.
