Pub Date : 1989-05-22DOI: 10.1109/PLASMA.1989.165973
N. Roderick, M. Frese, R. Peterkin, S. S. Payne
Two-dimensional single-fluid magnetohydrodynamic simulations have been conducted to investigate the effects of the Hall electric field on magnetic field transport in plasma opening switches of the type used on GAMBLE I. The Hall terms were included in the magnetic field transport equation in the two-dimensional simulation code MACH2 through the use of a generalized Ohm's law. Calculations show that the Hall terms augment the field transport previously observed to occur through ion fluid motion and diffusion. For modest values of microturbulent collision frequency, broad current channels were observed. Results also show the magnetic field transport to be affected by the cathode boundary conditions with the Hall terms included. In all cases, center-of-mass motion was slight.<>
{"title":"Magnetohydrodynamic simulations of Gamble I POS with Hall effect","authors":"N. Roderick, M. Frese, R. Peterkin, S. S. Payne","doi":"10.1109/PLASMA.1989.165973","DOIUrl":"https://doi.org/10.1109/PLASMA.1989.165973","url":null,"abstract":"Two-dimensional single-fluid magnetohydrodynamic simulations have been conducted to investigate the effects of the Hall electric field on magnetic field transport in plasma opening switches of the type used on GAMBLE I. The Hall terms were included in the magnetic field transport equation in the two-dimensional simulation code MACH2 through the use of a generalized Ohm's law. Calculations show that the Hall terms augment the field transport previously observed to occur through ion fluid motion and diffusion. For modest values of microturbulent collision frequency, broad current channels were observed. Results also show the magnetic field transport to be affected by the cathode boundary conditions with the Hall terms included. In all cases, center-of-mass motion was slight.<<ETX>>","PeriodicalId":165717,"journal":{"name":"IEEE 1989 International Conference on Plasma Science","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116547879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-22DOI: 10.1109/PLASMA.1989.166111
A. Drobot, A. Friedman, M. Fritts, I. Lottati, D. J. Nielsen
Summary form only. The use of unstructured grids provides some inherent advantages in the accurate simulation of plasma problems that involve complex configurations and where the treatment of complicated boundaries is important. The use of a triangular grid in two dimensions and of a tetrahedral grid with arbitrary connectivity in three dimensions allows a straightforward representation of complex geometries and allows the resolution of the mesh to vary according to the requirements of a problem. The authors have constructed a very simple and efficient data structure to represent unstructured grids for geometries with arbitrarily shaped boundaries. The data contains information about the location of vertices, edges, sides, and cells and permits with one degree of indirectness the implementation of algorithms for field solvers and for particle orbit integration. The numerical algorithms that have been constructed include a potential solver, an electromagnetic solver for both the time and frequency domain, and a particle-in-cell simulation. The efficiency and vectorization of the basic code functions are retained and yield timing results comparable with structured mesh codes.<>
{"title":"Numerical simulation of plasmas on an unstructured grid","authors":"A. Drobot, A. Friedman, M. Fritts, I. Lottati, D. J. Nielsen","doi":"10.1109/PLASMA.1989.166111","DOIUrl":"https://doi.org/10.1109/PLASMA.1989.166111","url":null,"abstract":"Summary form only. The use of unstructured grids provides some inherent advantages in the accurate simulation of plasma problems that involve complex configurations and where the treatment of complicated boundaries is important. The use of a triangular grid in two dimensions and of a tetrahedral grid with arbitrary connectivity in three dimensions allows a straightforward representation of complex geometries and allows the resolution of the mesh to vary according to the requirements of a problem. The authors have constructed a very simple and efficient data structure to represent unstructured grids for geometries with arbitrarily shaped boundaries. The data contains information about the location of vertices, edges, sides, and cells and permits with one degree of indirectness the implementation of algorithms for field solvers and for particle orbit integration. The numerical algorithms that have been constructed include a potential solver, an electromagnetic solver for both the time and frequency domain, and a particle-in-cell simulation. The efficiency and vectorization of the basic code functions are retained and yield timing results comparable with structured mesh codes.<<ETX>>","PeriodicalId":165717,"journal":{"name":"IEEE 1989 International Conference on Plasma Science","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125103367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-22DOI: 10.1109/PLASMA.1989.165992
T. Kho, A. T. Lin
Computer simulations were used to examine the detailed physics of magnetic field tapering and frequency detuning in a cyclotron autoresonance maser (CARM) amplifier and the dependence of its efficiency on electron beam current and input wave intensity. It was found that, depending on the initial frequency mismatch, tapering the magnetic field with either a negative or a positive gradient can enhance the efficiency over that of the resonantly tuned CARM. The ability of tapering to enhance the efficiency depends on the initial frequency mismatch. For a given set of parameters, the efficiency increases with beam current up to a critical current beyond which the efficiency decreases with increasing current. The decrease in efficiency results from the dominance of force bunching over inertial bunching in the electron-wave interaction. In the force-bunching regime, neither magnetic field tapering nor frequency detuning is effective in enhancing the efficiency.<>
{"title":"Efficiency optimization in a CARM amplifier","authors":"T. Kho, A. T. Lin","doi":"10.1109/PLASMA.1989.165992","DOIUrl":"https://doi.org/10.1109/PLASMA.1989.165992","url":null,"abstract":"Computer simulations were used to examine the detailed physics of magnetic field tapering and frequency detuning in a cyclotron autoresonance maser (CARM) amplifier and the dependence of its efficiency on electron beam current and input wave intensity. It was found that, depending on the initial frequency mismatch, tapering the magnetic field with either a negative or a positive gradient can enhance the efficiency over that of the resonantly tuned CARM. The ability of tapering to enhance the efficiency depends on the initial frequency mismatch. For a given set of parameters, the efficiency increases with beam current up to a critical current beyond which the efficiency decreases with increasing current. The decrease in efficiency results from the dominance of force bunching over inertial bunching in the electron-wave interaction. In the force-bunching regime, neither magnetic field tapering nor frequency detuning is effective in enhancing the efficiency.<<ETX>>","PeriodicalId":165717,"journal":{"name":"IEEE 1989 International Conference on Plasma Science","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131555502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-22DOI: 10.1109/PLASMA.1989.166096
K. H. Becker
The author is studying the electron-impact dissociation of NF/sub 3/, CF/sub 4/, SF/sub 6/, BCl/sub 3/ and CCl/sub 2/F/sub 2/, which are among the most commonly employed reactive constituents of etchant gas plasmas. The objective is to determine absolute cross sections and appearance potentials for the formation of the various radiating, metastable, and neutral ground-state fragments that are produced by controlled electron-impact dissociation of these molecules. Experimental techniques include electron and optical emission spectroscopy, mass spectroscopy time-of-flight (TOF), and laser-induced fluorescence techniques. Results on molecular emissions in the near ultraviolet region of the optical spectrum are reported. These include the emission of the BCl A to X band system from BCl/sub 3/, the CCl A to X and CCl/sup +/ A to X band systems from CCl/sub 2/F/sub 2/, and continuous UV emissions following dissociative electron impact on SF/sub 6/ and NF/sub 3/.<>
{"title":"Electron collisions with processing plasma constituents","authors":"K. H. Becker","doi":"10.1109/PLASMA.1989.166096","DOIUrl":"https://doi.org/10.1109/PLASMA.1989.166096","url":null,"abstract":"The author is studying the electron-impact dissociation of NF/sub 3/, CF/sub 4/, SF/sub 6/, BCl/sub 3/ and CCl/sub 2/F/sub 2/, which are among the most commonly employed reactive constituents of etchant gas plasmas. The objective is to determine absolute cross sections and appearance potentials for the formation of the various radiating, metastable, and neutral ground-state fragments that are produced by controlled electron-impact dissociation of these molecules. Experimental techniques include electron and optical emission spectroscopy, mass spectroscopy time-of-flight (TOF), and laser-induced fluorescence techniques. Results on molecular emissions in the near ultraviolet region of the optical spectrum are reported. These include the emission of the BCl A to X band system from BCl/sub 3/, the CCl A to X and CCl/sup +/ A to X band systems from CCl/sub 2/F/sub 2/, and continuous UV emissions following dissociative electron impact on SF/sub 6/ and NF/sub 3/.<<ETX>>","PeriodicalId":165717,"journal":{"name":"IEEE 1989 International Conference on Plasma Science","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121795541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-22DOI: 10.1109/PLASMA.1989.166029
A. Sedghinasab
In a paper by P. Baessler and M. Kock (J. Phys. B, vol.13, p.1351, 1980), a 2 lambda interferometric technique is used to determine the electron number density, n/sub e/, in a pure argon plasma generated in a wall stabilized arc. Hydrogen is then added to obtain the reduced linewidth of the Balmer line H/sub beta /. Baessler and Kock then use an electron density correction factor to correct the transition probabilities obtained from experiments using hydrogen for n/sub e/ determination. Their result neglects the temperature change due to the modification to the electron density. The present author has shown that their correction factor is invalid and results in transition probability corrections that are in error by 30-200%.<>
{"title":"Argon transition probabilities revisited","authors":"A. Sedghinasab","doi":"10.1109/PLASMA.1989.166029","DOIUrl":"https://doi.org/10.1109/PLASMA.1989.166029","url":null,"abstract":"In a paper by P. Baessler and M. Kock (J. Phys. B, vol.13, p.1351, 1980), a 2 lambda interferometric technique is used to determine the electron number density, n/sub e/, in a pure argon plasma generated in a wall stabilized arc. Hydrogen is then added to obtain the reduced linewidth of the Balmer line H/sub beta /. Baessler and Kock then use an electron density correction factor to correct the transition probabilities obtained from experiments using hydrogen for n/sub e/ determination. Their result neglects the temperature change due to the modification to the electron density. The present author has shown that their correction factor is invalid and results in transition probability corrections that are in error by 30-200%.<<ETX>>","PeriodicalId":165717,"journal":{"name":"IEEE 1989 International Conference on Plasma Science","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115136453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-22DOI: 10.1109/PLASMA.1989.166203
Y. Weng, M. Kushner
A method is described whereby electron-electron (e-e) collisions can be included in Monte Carlo simulations of electron swarms in low-temperature partially ionized plasmas. The method is based on treating e-e collisions in a manner equivalent to electron-neutral collisions by using the impact approximation (instantaneous momentum exchange). This equivalence permits the direct inclusion of e-e collisions in the selection process used for collisions by the Monte Carlo method and is obtained by having electrons collide with a background electron fluid. Momentum exchange occurs with the fluid, thereby requiring periodic updates of the electron energy distribution function of the background fluid. This method is made computationally feasible by use of a modified null cross section technique. For typical discharge conditions (3 torr N/sub 2/, delta =10/sup -5/, E/N=20*10/sup -17/ V-cm/sup 2/) the method converges in less than tens of nanoseconds, making application to systems operating at greater than or equal to tens of megahertz possible.<>
{"title":"Including electron-electron collisions in Monte Carlo simulations of swarms in partially ionized plasmas","authors":"Y. Weng, M. Kushner","doi":"10.1109/PLASMA.1989.166203","DOIUrl":"https://doi.org/10.1109/PLASMA.1989.166203","url":null,"abstract":"A method is described whereby electron-electron (e-e) collisions can be included in Monte Carlo simulations of electron swarms in low-temperature partially ionized plasmas. The method is based on treating e-e collisions in a manner equivalent to electron-neutral collisions by using the impact approximation (instantaneous momentum exchange). This equivalence permits the direct inclusion of e-e collisions in the selection process used for collisions by the Monte Carlo method and is obtained by having electrons collide with a background electron fluid. Momentum exchange occurs with the fluid, thereby requiring periodic updates of the electron energy distribution function of the background fluid. This method is made computationally feasible by use of a modified null cross section technique. For typical discharge conditions (3 torr N/sub 2/, delta =10/sup -5/, E/N=20*10/sup -17/ V-cm/sup 2/) the method converges in less than tens of nanoseconds, making application to systems operating at greater than or equal to tens of megahertz possible.<<ETX>>","PeriodicalId":165717,"journal":{"name":"IEEE 1989 International Conference on Plasma Science","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134201598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-22DOI: 10.1109/PLASMA.1989.166022
S. Hu, V. Varadarajan, G. Miley
Ash control in the long-pulse tokamaks such as the ITER is addressed from the point of view of sawtooth pumping and fishbone excitation. An analytic model for predicting the influence of sawtooth and edge pumping on the helium contamination has been developed. One of its uses is to compute the ash density level for a given fusion power versus helium pumping fraction. The change of ash concentration due to sawtooth disruptions is also evaluated. The results show that the helium contamination can be changed drastically if pumping is strong enough. The results also show that adding sawteeth to help remove the ash from the center of the plasma becomes useful when the temperature profiles are parabolic or flatter. The controlled excitation of fishbone oscillations can directly help to control the ash accumulation by ejecting the alphas as they slow down to low energies. Estimates of the fishbone instability threshold rule out low frequency fishbones.<>
{"title":"Ash and burn control in ITER-type tokamak","authors":"S. Hu, V. Varadarajan, G. Miley","doi":"10.1109/PLASMA.1989.166022","DOIUrl":"https://doi.org/10.1109/PLASMA.1989.166022","url":null,"abstract":"Ash control in the long-pulse tokamaks such as the ITER is addressed from the point of view of sawtooth pumping and fishbone excitation. An analytic model for predicting the influence of sawtooth and edge pumping on the helium contamination has been developed. One of its uses is to compute the ash density level for a given fusion power versus helium pumping fraction. The change of ash concentration due to sawtooth disruptions is also evaluated. The results show that the helium contamination can be changed drastically if pumping is strong enough. The results also show that adding sawteeth to help remove the ash from the center of the plasma becomes useful when the temperature profiles are parabolic or flatter. The controlled excitation of fishbone oscillations can directly help to control the ash accumulation by ejecting the alphas as they slow down to low energies. Estimates of the fishbone instability threshold rule out low frequency fishbones.<<ETX>>","PeriodicalId":165717,"journal":{"name":"IEEE 1989 International Conference on Plasma Science","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133808089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-22DOI: 10.1109/PLASMA.1989.166015
R. Williams, C. Clayton, C. Joshi, W. Leemans, K. Marsh, T. Katsouleas, W. Mori
The trajectories of relativistic electrons ( gamma =4), injected into the potentials of three-dimensional relativistic plasma waves ( gamma /sub ph/=13.5), have been calculated using Monte Carlo simulation techniques in order to predict quantitatively the output of laser plasma beatwave acceleration experiments. The calculations have permitted the analysis of accelerated (and decelerated) electrons according to the quantity of electrons accelerated, the angular distribution, and the energy spectrum. The calculations have also guided the modification of the electron detection system in order to optimize electron transport and maximize detection efficiency. The radial fields (focusing and defocusing) and longitudinal fields (accelerating and decelerating) that result in the number of electrons accelerated being several orders of magnitude lower than the number injected have been analyzed. The angular distribution of accelerated electrons as a function of final electron energy has been predicted, as well as the final energy spectrum and how it depends on the accelerating-field-accelerating-length product. The maximum electron energy gain possible using a CO/sub 2/ laser running on 9.6- and 10.3- mu m wavelengths has been compared with the practical energy limit defined by the experimental limits of the machine.<>
{"title":"Studied of injected particle trajectories in the beat wave accelerator","authors":"R. Williams, C. Clayton, C. Joshi, W. Leemans, K. Marsh, T. Katsouleas, W. Mori","doi":"10.1109/PLASMA.1989.166015","DOIUrl":"https://doi.org/10.1109/PLASMA.1989.166015","url":null,"abstract":"The trajectories of relativistic electrons ( gamma =4), injected into the potentials of three-dimensional relativistic plasma waves ( gamma /sub ph/=13.5), have been calculated using Monte Carlo simulation techniques in order to predict quantitatively the output of laser plasma beatwave acceleration experiments. The calculations have permitted the analysis of accelerated (and decelerated) electrons according to the quantity of electrons accelerated, the angular distribution, and the energy spectrum. The calculations have also guided the modification of the electron detection system in order to optimize electron transport and maximize detection efficiency. The radial fields (focusing and defocusing) and longitudinal fields (accelerating and decelerating) that result in the number of electrons accelerated being several orders of magnitude lower than the number injected have been analyzed. The angular distribution of accelerated electrons as a function of final electron energy has been predicted, as well as the final energy spectrum and how it depends on the accelerating-field-accelerating-length product. The maximum electron energy gain possible using a CO/sub 2/ laser running on 9.6- and 10.3- mu m wavelengths has been compared with the practical energy limit defined by the experimental limits of the machine.<<ETX>>","PeriodicalId":165717,"journal":{"name":"IEEE 1989 International Conference on Plasma Science","volume":"267 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133889902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-22DOI: 10.1109/PLASMA.1989.166235
O. Barnouin, H. Chung, G. Miley
Pulsed nuclear irradiation of infrared window materials was performed at the TRIGA nuclear reactor. The pulse was 17 ms (FWHM) in duration, and the 0.1 Mrad dose consisted of 5% neutrons and 95% gamma rays. The samples under study included sapphire, CsI, ALON, and spinel. The radioluminescence exhibited by these samples during the irradiation was recorded and analyzed. Luminescence was observed in the 1.0-4.5 mu m range and in the visible range. The total emission over 1.0-4.5 mu m range was recorded with a PbSe detector with a cutoff wavelength of 4.5 mu m. Spectral information in the visible and near-infrared ranges was obtained with filters and with an optical multichannel analyzer. A kinetic model for radioluminescence was developed from the results.<>
{"title":"Study of the luminescence from infrared window materials undergoing pulsed nuclear irradiation","authors":"O. Barnouin, H. Chung, G. Miley","doi":"10.1109/PLASMA.1989.166235","DOIUrl":"https://doi.org/10.1109/PLASMA.1989.166235","url":null,"abstract":"Pulsed nuclear irradiation of infrared window materials was performed at the TRIGA nuclear reactor. The pulse was 17 ms (FWHM) in duration, and the 0.1 Mrad dose consisted of 5% neutrons and 95% gamma rays. The samples under study included sapphire, CsI, ALON, and spinel. The radioluminescence exhibited by these samples during the irradiation was recorded and analyzed. Luminescence was observed in the 1.0-4.5 mu m range and in the visible range. The total emission over 1.0-4.5 mu m range was recorded with a PbSe detector with a cutoff wavelength of 4.5 mu m. Spectral information in the visible and near-infrared ranges was obtained with filters and with an optical multichannel analyzer. A kinetic model for radioluminescence was developed from the results.<<ETX>>","PeriodicalId":165717,"journal":{"name":"IEEE 1989 International Conference on Plasma Science","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134063597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1989-05-22DOI: 10.1109/PLASMA.1989.166040
Y. Aoki, H. Kitagawa, K. Sumi, S. Oikawa, N. Kayukawa, H. Yamazaki
The value of the natural damping ratio, a', which is needed to calculate the density, N/sub k/, of potassium atoms in a magnetohydrodynamic plasma, has been determined experimentally. The choice of measurement frequency is discussed. The results showed that N/sub k/ in an ethyl-alcohol combustion plasma in which the potassium atom is 1 wt.% of the total components and at a temperature between 1700 and 2300 K is within the range 10/sup 22/-10/sup 23/ m/sup -3/. Since the total particle count in the combustion gas plasma is 3*10/sup 24/ approximately 4*10/sup 24/ m/sup -3/ in the above temperature range, the mol fraction of the potassium atoms as a percentage of the total components is 5*10/sup -3/ approximately 3*10/sup -2/. This value is much larger than the mol fraction of potassium atoms obtained under conditions of chemical reaction equilibrium. This is considered to be the chief cause of water drops during experiments and greatly influences the optical measurement of solid-state seed materials.<>
{"title":"The potassium atom density distribution and plasma temperature profile in an MHD channel","authors":"Y. Aoki, H. Kitagawa, K. Sumi, S. Oikawa, N. Kayukawa, H. Yamazaki","doi":"10.1109/PLASMA.1989.166040","DOIUrl":"https://doi.org/10.1109/PLASMA.1989.166040","url":null,"abstract":"The value of the natural damping ratio, a', which is needed to calculate the density, N/sub k/, of potassium atoms in a magnetohydrodynamic plasma, has been determined experimentally. The choice of measurement frequency is discussed. The results showed that N/sub k/ in an ethyl-alcohol combustion plasma in which the potassium atom is 1 wt.% of the total components and at a temperature between 1700 and 2300 K is within the range 10/sup 22/-10/sup 23/ m/sup -3/. Since the total particle count in the combustion gas plasma is 3*10/sup 24/ approximately 4*10/sup 24/ m/sup -3/ in the above temperature range, the mol fraction of the potassium atoms as a percentage of the total components is 5*10/sup -3/ approximately 3*10/sup -2/. This value is much larger than the mol fraction of potassium atoms obtained under conditions of chemical reaction equilibrium. This is considered to be the chief cause of water drops during experiments and greatly influences the optical measurement of solid-state seed materials.<<ETX>>","PeriodicalId":165717,"journal":{"name":"IEEE 1989 International Conference on Plasma Science","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115338269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：