Rotationally inelastic He-H_(2),D_(2),T_(2) collision was studied quantum-mechanically.Converged cross sections were calculated by using the close coupling method for relative kinetic energies of 0.01 to 0.54 eV.Born-...Rotationally inelastic He-H_(2),D_(2),T_(2) collision was studied quantum-mechanically.Converged cross sections were calculated by using the close coupling method for relative kinetic energies of 0.01 to 0.54 eV.Born-Oppenheimer approximation was employed to determine the potential surface of He-D_(2),He-T_(2),and He-H_(2).Careful comparison between the cross sections of the isotopically substituted systems was carried out,and the regular changes of the total cross sections of the isotopically substituted He-H_(2) colliding systems were obtained.展开更多
A technique of flat crystal x-ray spectrometer for quantitative spectral measurement is described.For the flat crystal spectrograph geometry,the quantitative reduction of relating the CCD counts back to the photon flu...A technique of flat crystal x-ray spectrometer for quantitative spectral measurement is described.For the flat crystal spectrograph geometry,the quantitative reduction of relating the CCD counts back to the photon flux from the x-ray source is established.The absolute calibrations of the integral diffraction coefficients of the crystal and the CCD sensitivity make it possible to measure absolute photons flux within the energy range of 2000–5000 eV.The uncertainty analysis of the calibrations is carried out to obtain the energy resolved uncertainties of crystal and CCD.Thus,the experimental spectra with spectral resolved intensity uncertainties are available.Then,a performing experiment of laser-produced Ti plasma is carried out and the absolute x-ray spectra with intensity uncertainty less than 8.5%are obtained.The technique is promising for absolute spectral measurement of high temperature plasmas in a kilo-electron-volt region.展开更多
文摘Rotationally inelastic He-H_(2),D_(2),T_(2) collision was studied quantum-mechanically.Converged cross sections were calculated by using the close coupling method for relative kinetic energies of 0.01 to 0.54 eV.Born-Oppenheimer approximation was employed to determine the potential surface of He-D_(2),He-T_(2),and He-H_(2).Careful comparison between the cross sections of the isotopically substituted systems was carried out,and the regular changes of the total cross sections of the isotopically substituted He-H_(2) colliding systems were obtained.
基金by the National High-Tech Program of China and the National Natural Science Foundation of China under Grant Nos 10734140,10874156 and 10875109.
文摘A technique of flat crystal x-ray spectrometer for quantitative spectral measurement is described.For the flat crystal spectrograph geometry,the quantitative reduction of relating the CCD counts back to the photon flux from the x-ray source is established.The absolute calibrations of the integral diffraction coefficients of the crystal and the CCD sensitivity make it possible to measure absolute photons flux within the energy range of 2000–5000 eV.The uncertainty analysis of the calibrations is carried out to obtain the energy resolved uncertainties of crystal and CCD.Thus,the experimental spectra with spectral resolved intensity uncertainties are available.Then,a performing experiment of laser-produced Ti plasma is carried out and the absolute x-ray spectra with intensity uncertainty less than 8.5%are obtained.The technique is promising for absolute spectral measurement of high temperature plasmas in a kilo-electron-volt region.