Tansmission grating spectrometers are extensively used to measure absthlute X-ray spectra in a photon-energy range below 1000 eV. The transmission grating,as its dispersive element, must be calibrated to obtain its da...Tansmission grating spectrometers are extensively used to measure absthlute X-ray spectra in a photon-energy range below 1000 eV. The transmission grating,as its dispersive element, must be calibrated to obtain its danaction efficiencies. Calibrations of absolute distraction efficiencies of the tlansmission grating at photon energyof 844eV have been carried out on Beliing Synchrotron mediation Facility. With theaid of grating model, all of the grating structure paraxneters have been determinedand the absolute dchaction efficiencies in a photon-energy range below 2000eV havealso been calculated and discussed.展开更多
Gold disk targets were irradiated using focusing and beam smoothing methods on Xingguang (XG-Ⅱ) laser facilities with 350 nm wavelength,0.6 ns pulse width and 20-80 Joules energies. Laser absorption,light scattering ...Gold disk targets were irradiated using focusing and beam smoothing methods on Xingguang (XG-Ⅱ) laser facilities with 350 nm wavelength,0.6 ns pulse width and 20-80 Joules energies. Laser absorption,light scattering and X-ray conversion were experimentally investigated. The experimental results showed that laser ab-sorption and scattered light were about 90% and 10%,respectively,under focusing irradiation,but the laser absorption increased 5%-10% and the scattered light about 1% under the condition of beam smoothing. Compared with the case of fo-cusing irradiation,the laser absorption was effectively improved and the scattered light remarkably dropped under uniform irradiation; then due to the decrease in laser intensity,X-ray conversion increased. This is highly advantageous to the in-ertial confinement fusion. However,X-ray conversion mechanism basically did not change and X-ray conversion efficiency under beam smoothing and focusing irra-diation was basically the same.展开更多
Eight beams of 0.35μm laser with pulse duration of 1 ns and total energy of 2 kJ enter into a hohlraum to create intense X-ray radiation of 140 eV on the ShenguangΙΙlaser facility.Plastic foam(C6H12)and copper-dope...Eight beams of 0.35μm laser with pulse duration of 1 ns and total energy of 2 kJ enter into a hohlraum to create intense X-ray radiation of 140 eV on the ShenguangΙΙlaser facility.Plastic foam(C6H12)and copper-doped foam(C6H12Cu0.394)with a density of 50 mg/cm3 are heated by X-ray radiation emitted from the hohlraum.The breakout time of the radiation wave is measured by a tri-chromatic streaked X-ray spectrometer(TCS)that consists of a set of three imaging pinholes and an array of three transmission gratings coupled with an X-ray streak camera(XSC).At one shot,the simultaneous measurements of the delay of the drive source and the radiation transport at two energies(210 eV,840 eV)through the foam have been made for the first time.The experimental results indicate that the time delays vary with photon energies.With a transmission grating spectrometer(TGS),the spectra transmitting foams were measured,and the lower limit of the optical depth was measured.The radiation at energy of 210 eV propagates through plastic foam at a faster velocity,compared with the radiation at energy of 840 eV;while the results of copper-doped foam are reverse.The optical depth in the plastic foam is less than 1,and in the doped foam it is more than 1.展开更多
文摘Tansmission grating spectrometers are extensively used to measure absthlute X-ray spectra in a photon-energy range below 1000 eV. The transmission grating,as its dispersive element, must be calibrated to obtain its danaction efficiencies. Calibrations of absolute distraction efficiencies of the tlansmission grating at photon energyof 844eV have been carried out on Beliing Synchrotron mediation Facility. With theaid of grating model, all of the grating structure paraxneters have been determinedand the absolute dchaction efficiencies in a photon-energy range below 2000eV havealso been calculated and discussed.
文摘Gold disk targets were irradiated using focusing and beam smoothing methods on Xingguang (XG-Ⅱ) laser facilities with 350 nm wavelength,0.6 ns pulse width and 20-80 Joules energies. Laser absorption,light scattering and X-ray conversion were experimentally investigated. The experimental results showed that laser ab-sorption and scattered light were about 90% and 10%,respectively,under focusing irradiation,but the laser absorption increased 5%-10% and the scattered light about 1% under the condition of beam smoothing. Compared with the case of fo-cusing irradiation,the laser absorption was effectively improved and the scattered light remarkably dropped under uniform irradiation; then due to the decrease in laser intensity,X-ray conversion increased. This is highly advantageous to the in-ertial confinement fusion. However,X-ray conversion mechanism basically did not change and X-ray conversion efficiency under beam smoothing and focusing irra-diation was basically the same.
文摘Eight beams of 0.35μm laser with pulse duration of 1 ns and total energy of 2 kJ enter into a hohlraum to create intense X-ray radiation of 140 eV on the ShenguangΙΙlaser facility.Plastic foam(C6H12)and copper-doped foam(C6H12Cu0.394)with a density of 50 mg/cm3 are heated by X-ray radiation emitted from the hohlraum.The breakout time of the radiation wave is measured by a tri-chromatic streaked X-ray spectrometer(TCS)that consists of a set of three imaging pinholes and an array of three transmission gratings coupled with an X-ray streak camera(XSC).At one shot,the simultaneous measurements of the delay of the drive source and the radiation transport at two energies(210 eV,840 eV)through the foam have been made for the first time.The experimental results indicate that the time delays vary with photon energies.With a transmission grating spectrometer(TGS),the spectra transmitting foams were measured,and the lower limit of the optical depth was measured.The radiation at energy of 210 eV propagates through plastic foam at a faster velocity,compared with the radiation at energy of 840 eV;while the results of copper-doped foam are reverse.The optical depth in the plastic foam is less than 1,and in the doped foam it is more than 1.
