The Extreme Ultraviolet Camera （EUVC） onboard the Chang＇e-3 （CE-3） lander is used to observe the structure and dynamics of Earth＇s plasmasphere from the Moon. By detecting the resonance line emission of helium i...The Extreme Ultraviolet Camera （EUVC） onboard the Chang＇e-3 （CE-3） lander is used to observe the structure and dynamics of Earth＇s plasmasphere from the Moon. By detecting the resonance line emission of helium ions （He＋） at 30.4 nm, the EUVC images the entire plasmasphere with a time resolution of 10 min and a spatial resolution of about 0.1 Earth radius （RE） in a single frame. We first present details about the data processing from EUVC and the data acquisition in the commissioning phase, and then report some initial results, which reflect the basic features of the plas- masphere well. The photon count and emission intensity of EUVC are consistent with previous observations and models, which indicate that the EUVC works normally and can provide high quality data for future studies.展开更多
A grazing incidence flat-field spectrograph using a concave grating was constructed to measure extreme ultraviolet （EUV） emission from a CO 2 laser-produced tin plasma throughout the wavelength region of 5 nm to 20 ...A grazing incidence flat-field spectrograph using a concave grating was constructed to measure extreme ultraviolet （EUV） emission from a CO 2 laser-produced tin plasma throughout the wavelength region of 5 nm to 20 nm for lithography. Spectral efficiency of the EUV emission around 13.5 nm from plate, cavity, and thin foil tin targets was studied. By translating the focusing lens along the laser axis, the dependence of EUV spectra on the amount of defocus was investigated. The results showed that the spectral efficiency was higher for the cavity target in comparison to the plate or foil target, while it decreased with an increase in the defocus distance. The source＇s spectra and the EUV emission intensity normalized to the incident pulse energy at 45 from the target normal were characterized for the in-band （2% of bandwidth） region as a function of laser energy spanning from 46 mJ to 600 mJ for the pure tin plate target. The energy normalized EUV emission was found to increase with the increasing incident pulse energy. It reached the optimum value for the laser energy of around 343 mJ, after which it dropped rapidly.展开更多
In this paper,a CO_(2) laser induced discharge plasma extreme ultraviolet(EUV)source experimental device was established.The optical emission spectroscopy was used to diagnose the characteristics of the plasma,and the...In this paper,a CO_(2) laser induced discharge plasma extreme ultraviolet(EUV)source experimental device was established.The optical emission spectroscopy was used to diagnose the characteristics of the plasma,and the evolution of electron temperature and electron density with time was obtained.The influence of discharge voltage on plasma parameters was analyzed and discussed.The EUV radiation characteristics of the plasma were investigated by self-made grazing incidence EUV spectrometer.The EUV radiation intensity and conversion efficiency were discussed.展开更多
文摘The Extreme Ultraviolet Camera （EUVC） onboard the Chang＇e-3 （CE-3） lander is used to observe the structure and dynamics of Earth＇s plasmasphere from the Moon. By detecting the resonance line emission of helium ions （He＋） at 30.4 nm, the EUVC images the entire plasmasphere with a time resolution of 10 min and a spatial resolution of about 0.1 Earth radius （RE） in a single frame. We first present details about the data processing from EUVC and the data acquisition in the commissioning phase, and then report some initial results, which reflect the basic features of the plas- masphere well. The photon count and emission intensity of EUVC are consistent with previous observations and models, which indicate that the EUVC works normally and can provide high quality data for future studies.
基金supported by the Scientific Research Foundation of the Education Department of Hubei Province (No.Q20131512)National Natural Science Foundation of China (No.61078024)
文摘A grazing incidence flat-field spectrograph using a concave grating was constructed to measure extreme ultraviolet （EUV） emission from a CO 2 laser-produced tin plasma throughout the wavelength region of 5 nm to 20 nm for lithography. Spectral efficiency of the EUV emission around 13.5 nm from plate, cavity, and thin foil tin targets was studied. By translating the focusing lens along the laser axis, the dependence of EUV spectra on the amount of defocus was investigated. The results showed that the spectral efficiency was higher for the cavity target in comparison to the plate or foil target, while it decreased with an increase in the defocus distance. The source＇s spectra and the EUV emission intensity normalized to the incident pulse energy at 45 from the target normal were characterized for the in-band （2% of bandwidth） region as a function of laser energy spanning from 46 mJ to 600 mJ for the pure tin plate target. The energy normalized EUV emission was found to increase with the increasing incident pulse energy. It reached the optimum value for the laser energy of around 343 mJ, after which it dropped rapidly.
基金This work was supported by the Fundamental Research Funds for the Central Universities(HUST:2016YXMS028).
文摘In this paper,a CO_(2) laser induced discharge plasma extreme ultraviolet(EUV)source experimental device was established.The optical emission spectroscopy was used to diagnose the characteristics of the plasma,and the evolution of electron temperature and electron density with time was obtained.The influence of discharge voltage on plasma parameters was analyzed and discussed.The EUV radiation characteristics of the plasma were investigated by self-made grazing incidence EUV spectrometer.The EUV radiation intensity and conversion efficiency were discussed.
