Erperimental method to measure the prompt neutron spectra of 238U fissioninduced by fast neutrons has been developed at HI-13 Tandem Van de Grab Accelerator Laboratory of CIAE. These techniques employ a multi-segment ...Erperimental method to measure the prompt neutron spectra of 238U fissioninduced by fast neutrons has been developed at HI-13 Tandem Van de Grab Accelerator Laboratory of CIAE. These techniques employ a multi-segment fission chamberand tab liquid scintillator neutron detectors. TOF (time of flight) techniques are usedfor prilnny neutrons to select the fission evellts induced by monoenergetic neutronfrom 'H(d, n) reactions instead of breakup neutrons from 'H(d, up) reactions. Thefission neutron TOF spectra are measured in coincidence with the fission fragmellts todistinguish fission neutrons from other secondals neutrons. The method perests measurements to a forly good accuracy under large neutron and gamma ray baCkgroulld.The tecboques are described and experimelltal spectra are presented.展开更多
A new kind of electron source, the photoemissive monoenergetic electron source has been invented for calibrating the beta--magnetic spectrometer. It produceselectrons in the form of simulating a radioactive monoenerge...A new kind of electron source, the photoemissive monoenergetic electron source has been invented for calibrating the beta--magnetic spectrometer. It produceselectrons in the form of simulating a radioactive monoenergetic electron source andcan be made in any shape and size according tO the demands of experimentS. In thispaper, the principles and basic constructions of the photoemissive monoenergeticelectron source are described, the resultS of calibrating our 2’l’x bead--magneticspectrometer with a single strip arc shaped photoemissive monoenergetic electronsource are listed, a new way for determining resolution function of experimentslsystem in the research of neutrino rest mass has been posed and one of its actualapplications is also given.展开更多
We study the global umbilic submanifolds with parallel mean curvature vector fields in a Riemannian manifold with quasi constant curvature and get a local pinching theorem about the length of the second fundamental form.
In this paper,it is proved that the Sasakian anti-holomorphic submanifolds of a Kaehlerian manifold is characterized by D-totally umbilical,and some curvature properties of the CR-submanifolds are ohtained.
文摘Erperimental method to measure the prompt neutron spectra of 238U fissioninduced by fast neutrons has been developed at HI-13 Tandem Van de Grab Accelerator Laboratory of CIAE. These techniques employ a multi-segment fission chamberand tab liquid scintillator neutron detectors. TOF (time of flight) techniques are usedfor prilnny neutrons to select the fission evellts induced by monoenergetic neutronfrom 'H(d, n) reactions instead of breakup neutrons from 'H(d, up) reactions. Thefission neutron TOF spectra are measured in coincidence with the fission fragmellts todistinguish fission neutrons from other secondals neutrons. The method perests measurements to a forly good accuracy under large neutron and gamma ray baCkgroulld.The tecboques are described and experimelltal spectra are presented.
文摘A new kind of electron source, the photoemissive monoenergetic electron source has been invented for calibrating the beta--magnetic spectrometer. It produceselectrons in the form of simulating a radioactive monoenergetic electron source andcan be made in any shape and size according tO the demands of experimentS. In thispaper, the principles and basic constructions of the photoemissive monoenergeticelectron source are described, the resultS of calibrating our 2’l’x bead--magneticspectrometer with a single strip arc shaped photoemissive monoenergetic electronsource are listed, a new way for determining resolution function of experimentslsystem in the research of neutrino rest mass has been posed and one of its actualapplications is also given.
基金Supported by the Directing Research Subject of Jiangsu Education Bureau(03103146)
文摘We study the global umbilic submanifolds with parallel mean curvature vector fields in a Riemannian manifold with quasi constant curvature and get a local pinching theorem about the length of the second fundamental form.
文摘In this paper,it is proved that the Sasakian anti-holomorphic submanifolds of a Kaehlerian manifold is characterized by D-totally umbilical,and some curvature properties of the CR-submanifolds are ohtained.
