In this work, experiment investigations and simulation studies of a waveguide-based microwave plasma source operated at 2.45 GHz in atmospheric pressure helium gas are presented. The plasma source has been designed in...In this work, experiment investigations and simulation studies of a waveguide-based microwave plasma source operated at 2.45 GHz in atmospheric pressure helium gas are presented. The plasma source has been designed in conjunction with a gas spectrograph as a speciation analysis tool. Emitted He spectra are observed for gas flow rates between （0.2-1） L/min and microwave power in the range （15-150） W. The results obtained demonstrate maximum excitation temperature of about 3800 K and gas temperature of about 2000 K. Mixtures containing small amounts of mercury atoms are considered and the resonant emission of Hg atoms at 253.56 nm is detected. The spectroscopic measurements are completed with a collisional radiative model delivering the electron density and temperature, the amplitude of the electric microwave field, and the population of the excited atomic states for a given absorbed power and gas temperature, The electromagnetic field distribution in the plasma source is obtained by solving Maxwell＇s equations. Electric field strength of several 10^5 V/m is obtained that agrees well with the results of the collisional radiative model. The calculated and measured line intensity ratios of He spectral lines agree within 300/0-40%.展开更多
The Atmospheric Ultraviolet Radiance Integrated Code （AURIC） is a software package developed by Computa- tional Physics, Inc. （CPI） under the sponsorship of the Air Force Phillips Laboratory/Geophysics Directorate...The Atmospheric Ultraviolet Radiance Integrated Code （AURIC） is a software package developed by Computa- tional Physics, Inc. （CPI） under the sponsorship of the Air Force Phillips Laboratory/Geophysics Directorate （PL/GP） （cur- rently the Air Force Research Laboratory） for middle and upper atmospheric radiance modeling from the far ultraviolet to the near infrared. The AURIC has been considered as a general model for the radiative transfer simulation of airglow. Based on the theory of MODerate resolution atmospheric TRANsmission （MODTRAN）, the AURIC extends calculation to altitudes above 100 km and the wavelength down to 80 nm. A package of AURIC vl.2 was released in 2002, which can be used for sin- gle-point simulation from 1947 to 1999. It means that the model is not suitable for atmospheric simulation of large datasets or for atmospheric parameters retrieval from amount of satellite measurements. In this paper, AURIC vl.2 is upgraded to AURIC-2012 based on MATLAB with improvements for modules of the Geomagnetic Parameter （GEOPARM）, Atmosphere neutral composition （ATOMS）, and Ionospheric electron density （IONOS）. The improved AURIC can be used for global au- tomatic airglow simulation and also for automatic retrieval of atmospheric compositions from satellite global observations, such as O/N2 and electron density etc. Besides, the model supplies possibilities for further improvement of airglow radiative mechanism and for substitution of other modules. Based on the AURIC-2012, Limb Column Emission Intensity （L-CEI） and Volume Emission Rate （VER） are calculated. For validation, the results were compared with measurements of the Global Ul- traviolet Imager （GUVI） and TIMED Doppler Interferometer （TIDI）, respectively. The averaged relative errors of L-CEI and VER at peak altitude are both within 20%. Finally, L-CEI varying with latitude, altitude, solar activity, and geomagnetic activ- ity is simulated, and the distribution characteristics of the simulation and their influencing factors are analyzed subsequently.展开更多
文摘In this work, experiment investigations and simulation studies of a waveguide-based microwave plasma source operated at 2.45 GHz in atmospheric pressure helium gas are presented. The plasma source has been designed in conjunction with a gas spectrograph as a speciation analysis tool. Emitted He spectra are observed for gas flow rates between （0.2-1） L/min and microwave power in the range （15-150） W. The results obtained demonstrate maximum excitation temperature of about 3800 K and gas temperature of about 2000 K. Mixtures containing small amounts of mercury atoms are considered and the resonant emission of Hg atoms at 253.56 nm is detected. The spectroscopic measurements are completed with a collisional radiative model delivering the electron density and temperature, the amplitude of the electric microwave field, and the population of the excited atomic states for a given absorbed power and gas temperature, The electromagnetic field distribution in the plasma source is obtained by solving Maxwell＇s equations. Electric field strength of several 10^5 V/m is obtained that agrees well with the results of the collisional radiative model. The calculated and measured line intensity ratios of He spectral lines agree within 300/0-40%.
基金funded by the Strategic Pilot Projects in Space Science of Chinese Academy of Sciences(Grant No.XDA04060202)
文摘The Atmospheric Ultraviolet Radiance Integrated Code （AURIC） is a software package developed by Computa- tional Physics, Inc. （CPI） under the sponsorship of the Air Force Phillips Laboratory/Geophysics Directorate （PL/GP） （cur- rently the Air Force Research Laboratory） for middle and upper atmospheric radiance modeling from the far ultraviolet to the near infrared. The AURIC has been considered as a general model for the radiative transfer simulation of airglow. Based on the theory of MODerate resolution atmospheric TRANsmission （MODTRAN）, the AURIC extends calculation to altitudes above 100 km and the wavelength down to 80 nm. A package of AURIC vl.2 was released in 2002, which can be used for sin- gle-point simulation from 1947 to 1999. It means that the model is not suitable for atmospheric simulation of large datasets or for atmospheric parameters retrieval from amount of satellite measurements. In this paper, AURIC vl.2 is upgraded to AURIC-2012 based on MATLAB with improvements for modules of the Geomagnetic Parameter （GEOPARM）, Atmosphere neutral composition （ATOMS）, and Ionospheric electron density （IONOS）. The improved AURIC can be used for global au- tomatic airglow simulation and also for automatic retrieval of atmospheric compositions from satellite global observations, such as O/N2 and electron density etc. Besides, the model supplies possibilities for further improvement of airglow radiative mechanism and for substitution of other modules. Based on the AURIC-2012, Limb Column Emission Intensity （L-CEI） and Volume Emission Rate （VER） are calculated. For validation, the results were compared with measurements of the Global Ul- traviolet Imager （GUVI） and TIMED Doppler Interferometer （TIDI）, respectively. The averaged relative errors of L-CEI and VER at peak altitude are both within 20%. Finally, L-CEI varying with latitude, altitude, solar activity, and geomagnetic activ- ity is simulated, and the distribution characteristics of the simulation and their influencing factors are analyzed subsequently.
