This study investigates the performance of a new compact(55 cm×56 cm×48 cm)in situ spin-exchange optical pumping ^(3)He neutron spin filter(NSF)system developed at the China Spallation Neutron Source.The enc...This study investigates the performance of a new compact(55 cm×56 cm×48 cm)in situ spin-exchange optical pumping ^(3)He neutron spin filter(NSF)system developed at the China Spallation Neutron Source.The enclosed NSF cell,filled with3He at 2.53 bar,achieved an initial ^(3)He polarization of approximately 60%.After subsequent improvements in the magnetic field and heating system,this in situ system achieved a ^(3)He polarization of 75.66%±0.09%,resulting in 96.30%neutron polarization at 2A.This highly compact in situ system is equipped with self-supportive features,pre-pumping capabilities,polarization maintenance,and a low-noise nuclear magnetic resonance system.These advantages significantly reduce the preparation time and simplify polarized neutron experiments,making it suitable for various neutron beamlines in China,particularly those with a limited sample space.These characteristics establish it as a quasi-standardized system that plays a vital role in polarized neutron experiments,including those involving polarized neutron imaging,neutron reflection,the performance calibration of polarized neutron instruments,and the neutron optics parity and time reversal experiment.展开更多
Failure of the steady solution of the master equation was analysed. It was found that the state of sustained oscillation exists only when the ratio of photon decay rate γ to injection rate r is satisfied. Based on th...Failure of the steady solution of the master equation was analysed. It was found that the state of sustained oscillation exists only when the ratio of photon decay rate γ to injection rate r is satisfied. Based on this understanding, a quantum mode micromaser theory was developed. The threshold ν th and photon distribution for π and 2π mode were calculated. The instability of quantum mode was analyzed as well.展开更多
基金supported by the National Science Fund for Distinguished Young Scholars(Grant No.12425512)the National Key Research and Development Program of China(Grant No.2020YFA0406000)+4 种基金the National Natural Science Foundation of China(Grant No.11875265)the Scientific Instrument Developing Project of the Chinese Academy of Sciences(Grant No.ZDKYYQ20190004)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2019B1515120079)Dongguan Introduction Program of Leading Innovative and Entrepreneurial Talents(Grant No.20191122)Guangdong Provincial Key Laboratory of Extreme Conditions,Dongguan Key Laboratory。
文摘This study investigates the performance of a new compact(55 cm×56 cm×48 cm)in situ spin-exchange optical pumping ^(3)He neutron spin filter(NSF)system developed at the China Spallation Neutron Source.The enclosed NSF cell,filled with3He at 2.53 bar,achieved an initial ^(3)He polarization of approximately 60%.After subsequent improvements in the magnetic field and heating system,this in situ system achieved a ^(3)He polarization of 75.66%±0.09%,resulting in 96.30%neutron polarization at 2A.This highly compact in situ system is equipped with self-supportive features,pre-pumping capabilities,polarization maintenance,and a low-noise nuclear magnetic resonance system.These advantages significantly reduce the preparation time and simplify polarized neutron experiments,making it suitable for various neutron beamlines in China,particularly those with a limited sample space.These characteristics establish it as a quasi-standardized system that plays a vital role in polarized neutron experiments,including those involving polarized neutron imaging,neutron reflection,the performance calibration of polarized neutron instruments,and the neutron optics parity and time reversal experiment.
文摘Failure of the steady solution of the master equation was analysed. It was found that the state of sustained oscillation exists only when the ratio of photon decay rate γ to injection rate r is satisfied. Based on this understanding, a quantum mode micromaser theory was developed. The threshold ν th and photon distribution for π and 2π mode were calculated. The instability of quantum mode was analyzed as well.
