Pub Date : 2017-05-01DOI: 10.1109/PLASMA.2017.8496350
Yangyang Fu, Guy M. Parsey, J. Krek, J. Verboncoeur, A. Christlieb, Xinxin Wang
A kinetic global model framework (KGMf) has been developed and used to investigate the similarity law in discharges at high pressure. Keeping the pd (gas pressure $times $ linear dimension) unchanged, the electron and ion densities in the steady state are calculated while the geometrical similar volume increases from micron scale $(500 ~mu mathrm {m})$ to millimeter scale (2.5mm) and at the pressure decreases from 760Torr to 152Torr, correspondently. In the model, electrons, positive ions and fourteen excited levels of argon atom are considered, and the transition of excitations, three-body collisions, and stepwise ionizations, which are forbidden processes from the similarity law are included and excluded, respectively1–3. The simulation results showed that within the forbidden processes the normalized density relations are below the predicted relations from the similarity law, which is attributed to the nonlinear impact of forbidden processes. Without the forbidden processes, the parameter relations are in good agreement with the theoretical prediction from the similarity law. The KGMf has the potential for deeper studies on similarity law at high pressure, such as gas mixtures with other volume and surface processes.
{"title":"Investigation of the Similarity Law in Discharges at High Pressure Using A Kinetic Global Model","authors":"Yangyang Fu, Guy M. Parsey, J. Krek, J. Verboncoeur, A. Christlieb, Xinxin Wang","doi":"10.1109/PLASMA.2017.8496350","DOIUrl":"https://doi.org/10.1109/PLASMA.2017.8496350","url":null,"abstract":"A kinetic global model framework (KGMf) has been developed and used to investigate the similarity law in discharges at high pressure. Keeping the pd (gas pressure $times $ linear dimension) unchanged, the electron and ion densities in the steady state are calculated while the geometrical similar volume increases from micron scale $(500 ~mu mathrm {m})$ to millimeter scale (2.5mm) and at the pressure decreases from 760Torr to 152Torr, correspondently. In the model, electrons, positive ions and fourteen excited levels of argon atom are considered, and the transition of excitations, three-body collisions, and stepwise ionizations, which are forbidden processes from the similarity law are included and excluded, respectively1–3. The simulation results showed that within the forbidden processes the normalized density relations are below the predicted relations from the similarity law, which is attributed to the nonlinear impact of forbidden processes. Without the forbidden processes, the parameter relations are in good agreement with the theoretical prediction from the similarity law. The KGMf has the potential for deeper studies on similarity law at high pressure, such as gas mixtures with other volume and surface processes.","PeriodicalId":145705,"journal":{"name":"2017 IEEE International Conference on Plasma Science (ICOPS)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127574213","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 : 2017-05-01DOI: 10.1109/PLASMA.2017.8495980
M. Hossain, Y. Ohtsu
We have proposed a radio frequency (RF) magnetized outer circular ring-shaped plasma sputtering source with a concentrically monopole arrangement of magnets with each gap of $d =5$mm for specific area target utilization [1–3]. The three setups, that is, with a center magnet, and type (a): magnet arrangement with three circles, type (b): magnet arrangement with two circles, and type (c): magnet arrangement with one circle are investigated from the point of view of specific area target utilization. The experiments were performed in stainless-steel cylindrical RF discharge chamber with outer diameter of 235 mm, inner diameter of 160 mm and 195 mm in height, where Ar gas pressure of 1.50 [Pa], and RF power of 50 [W] at 13.56 [MHz] are used to produce the plasma. From the 2D magnetic flux lines and their profiles, it is found that the magnetic flux density in component parallel to the target surface has a peak outside the exterior circle of magnets for all setups. Ring-shaped plasma in the specific outer area is observed at the position with the peak magnetic flux density and its diameter depends on a number of magnet circles. The results show that the target utilization can be controlled in the outer specific region near the wall. The typical RF magnetized plasma discharge, the RF discharge voltages, the self-bias dc voltages and the radial profiles of ion saturation currents, electron temperature and plasma density have been also investigated.
{"title":"Outer Circular Ringshaped RF Magnetized Plasma for Specificarea Target Utilization by Magnetic Monopole Arrangement","authors":"M. Hossain, Y. Ohtsu","doi":"10.1109/PLASMA.2017.8495980","DOIUrl":"https://doi.org/10.1109/PLASMA.2017.8495980","url":null,"abstract":"We have proposed a radio frequency (RF) magnetized outer circular ring-shaped plasma sputtering source with a concentrically monopole arrangement of magnets with each gap of $d =5$mm for specific area target utilization [1–3]. The three setups, that is, with a center magnet, and type (a): magnet arrangement with three circles, type (b): magnet arrangement with two circles, and type (c): magnet arrangement with one circle are investigated from the point of view of specific area target utilization. The experiments were performed in stainless-steel cylindrical RF discharge chamber with outer diameter of 235 mm, inner diameter of 160 mm and 195 mm in height, where Ar gas pressure of 1.50 [Pa], and RF power of 50 [W] at 13.56 [MHz] are used to produce the plasma. From the 2D magnetic flux lines and their profiles, it is found that the magnetic flux density in component parallel to the target surface has a peak outside the exterior circle of magnets for all setups. Ring-shaped plasma in the specific outer area is observed at the position with the peak magnetic flux density and its diameter depends on a number of magnet circles. The results show that the target utilization can be controlled in the outer specific region near the wall. The typical RF magnetized plasma discharge, the RF discharge voltages, the self-bias dc voltages and the radial profiles of ion saturation currents, electron temperature and plasma density have been also investigated.","PeriodicalId":145705,"journal":{"name":"2017 IEEE International Conference on Plasma Science (ICOPS)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127722705","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 : 2017-05-01DOI: 10.1109/PLASMA.2017.8496011
J. Jelonnek, G. Aiello, K. Avramidis, J. Franck, G. Gantenbein, S. Illy, Z. Ioannidis, J. Jin, P. Kalaria, I. Pagonakis, T. Rzesnicki, S. Ruess, T. Scherer, D. Strauss, M. Thumm, C. Wu
ECH&CD in future fusion reactors such as the European DEMOnstration power plant may require the availability of gyrotrons with operating frequency significantly above 200 GHz, RF output power of 2 MW, and total efficiency above 60 %. Depending on the technology for RF beam steering into the plasma, fast frequency tuning in steps of around 2 – 3 GHz might be required for plasma stability control. “Multi-purpose” operation at multiples of the λ/2-resonance frequency of the synthetic diamond gyrotron RF output window, hence in leaps of about 30 – 40 GHz might be considered for plasma start-up, heating and current drive. The combination of all those requirements challenges present-day technological limits for gyrotrons.
{"title":"Heading From W7-X Gyrotrons Towards Gyrotrons for Demo: Research Strategy and Recent Developments at Kit","authors":"J. Jelonnek, G. Aiello, K. Avramidis, J. Franck, G. Gantenbein, S. Illy, Z. Ioannidis, J. Jin, P. Kalaria, I. Pagonakis, T. Rzesnicki, S. Ruess, T. Scherer, D. Strauss, M. Thumm, C. Wu","doi":"10.1109/PLASMA.2017.8496011","DOIUrl":"https://doi.org/10.1109/PLASMA.2017.8496011","url":null,"abstract":"ECH&CD in future fusion reactors such as the European DEMOnstration power plant may require the availability of gyrotrons with operating frequency significantly above 200 GHz, RF output power of 2 MW, and total efficiency above 60 %. Depending on the technology for RF beam steering into the plasma, fast frequency tuning in steps of around 2 – 3 GHz might be required for plasma stability control. “Multi-purpose” operation at multiples of the λ/2-resonance frequency of the synthetic diamond gyrotron RF output window, hence in leaps of about 30 – 40 GHz might be considered for plasma start-up, heating and current drive. The combination of all those requirements challenges present-day technological limits for gyrotrons.","PeriodicalId":145705,"journal":{"name":"2017 IEEE International Conference on Plasma Science (ICOPS)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132762230","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 : 2017-05-01DOI: 10.1109/PLASMA.2017.8496117
A. Kone, B. Caillier, C. Muja, F. Sainct, P. Guillot
In past few decades, atmospheric pressure plasma jets (APPJs) has emerged as promising tool for numerous fields such as biomedical applications and analytical chemistry. Most of the studies are performed on free air conditions with helium as working gas. However, it has been reported that several modifications occurred on the APPJs propagation when the plasma jet interacts with a target 1. The aim of this study is to investigate the influence of a conductive target (copper plate) on a helium plasma jet characteristics.
{"title":"Experimental Study of the Interaction of an Helium Plasma Jet and a Conductive Target","authors":"A. Kone, B. Caillier, C. Muja, F. Sainct, P. Guillot","doi":"10.1109/PLASMA.2017.8496117","DOIUrl":"https://doi.org/10.1109/PLASMA.2017.8496117","url":null,"abstract":"In past few decades, atmospheric pressure plasma jets (APPJs) has emerged as promising tool for numerous fields such as biomedical applications and analytical chemistry. Most of the studies are performed on free air conditions with helium as working gas. However, it has been reported that several modifications occurred on the APPJs propagation when the plasma jet interacts with a target 1. The aim of this study is to investigate the influence of a conductive target (copper plate) on a helium plasma jet characteristics.","PeriodicalId":145705,"journal":{"name":"2017 IEEE International Conference on Plasma Science (ICOPS)","volume":"200 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133192535","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 : 2017-05-01DOI: 10.1109/PLASMA.2017.8496226
N. Alasgarzade, H. Altan, D. Mansuroglu, A. Sahin, I. Uzun-Kaymak
Commercially available Glow Discharge Detectors (GDDs) are often employed to detect mm-wave/THz radiation. Properties of the discharge are expected to have a significant effect on the responsivity of the detector 1–2. On the other hand, the mechanism behind the radiation detection remains a mystery. To answer such problem, one has to study the effect of radiation in the discharge itself.
{"title":"Effects Of Thz Transmission On The Narrow Gap Dc Glow Discharge Plasmas","authors":"N. Alasgarzade, H. Altan, D. Mansuroglu, A. Sahin, I. Uzun-Kaymak","doi":"10.1109/PLASMA.2017.8496226","DOIUrl":"https://doi.org/10.1109/PLASMA.2017.8496226","url":null,"abstract":"Commercially available Glow Discharge Detectors (GDDs) are often employed to detect mm-wave/THz radiation. Properties of the discharge are expected to have a significant effect on the responsivity of the detector 1–2. On the other hand, the mechanism behind the radiation detection remains a mystery. To answer such problem, one has to study the effect of radiation in the discharge itself.","PeriodicalId":145705,"journal":{"name":"2017 IEEE International Conference on Plasma Science (ICOPS)","volume":"189 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133320141","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 : 2017-05-01DOI: 10.1109/PLASMA.2017.8496274
Magesh T. Rajan, J. Turner, L. Pinnell, James J. Tallman, Emille Moreno
Our Plasma Engineering Research Lab (PERL) has been developing a variety of non-thermal plasma discharges for a range of applications. One of our recent development is a portable table-top atmospheric pressure non-thermal air plasma system using a resistive barrier discharge configuration that has been designed and developed for bacterial decontamination, pasteurization and sterilization of a range of items in a very simple one-touch operation. In this work, we will present the results of inactivation efficacies of bacteria that causes food borne illnesses. The portable tabletop atmospheric pressure non-thermal air plasma system is designed to inactivate bacteria in food of varied surface texture such as chicken, egg, seafood, vegetables and fruits. The portable table-top atmospheric pressure non-thermal air plasma system is designed to function at standard 50–60 Hz low frequency AC power input and in the ambient air. The core resistive barrier plasma setup used in this system is well characterized by our group. Ozone, and nitric oxides (NO) were observed to be the predominant long lived reactive species produced by the portable table-top atmospheric pressure non-thermal air plasma system. The results of the bacterial inactivation on variety of food surfaces will be presented in detail.
{"title":"Atmospheric Pressure Cold Plasma Application for Food Safety","authors":"Magesh T. Rajan, J. Turner, L. Pinnell, James J. Tallman, Emille Moreno","doi":"10.1109/PLASMA.2017.8496274","DOIUrl":"https://doi.org/10.1109/PLASMA.2017.8496274","url":null,"abstract":"Our Plasma Engineering Research Lab (PERL) has been developing a variety of non-thermal plasma discharges for a range of applications. One of our recent development is a portable table-top atmospheric pressure non-thermal air plasma system using a resistive barrier discharge configuration that has been designed and developed for bacterial decontamination, pasteurization and sterilization of a range of items in a very simple one-touch operation. In this work, we will present the results of inactivation efficacies of bacteria that causes food borne illnesses. The portable tabletop atmospheric pressure non-thermal air plasma system is designed to inactivate bacteria in food of varied surface texture such as chicken, egg, seafood, vegetables and fruits. The portable table-top atmospheric pressure non-thermal air plasma system is designed to function at standard 50–60 Hz low frequency AC power input and in the ambient air. The core resistive barrier plasma setup used in this system is well characterized by our group. Ozone, and nitric oxides (NO) were observed to be the predominant long lived reactive species produced by the portable table-top atmospheric pressure non-thermal air plasma system. The results of the bacterial inactivation on variety of food surfaces will be presented in detail.","PeriodicalId":145705,"journal":{"name":"2017 IEEE International Conference on Plasma Science (ICOPS)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133354253","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 : 2017-05-01DOI: 10.1109/PLASMA.2017.8496271
A. Povilus, Y. Podpaly, L. Cooper, B. Shaw, S. Chapman, E. Koh, S. Falabella, A. Schmidt
The dense plasma focus (DPF) is a z-pinch device that starts as a coaxial plasma railgun and ends in an implosion phase. DPF's historically were developed as thermonuclear devices. When used with deuterium and tritium gases a DPF can be used to produce neutrons; however, in operation, DPF's often suffered from inconsistent behavior, and the mechanisms driving the neutron production were poorly understood. Using kinetic modeling techniques recently developed at LLNL, we have gained insight into the mechanisms that lead to particle acceleration in the pinch region and can make informed design decisions for optimizing DPF behavior, from sub-kilojoule to mega-joule scale devices. Experimental DPF platforms at LLNL also serve to validate the behaviors seen in simulations and improve device performance with a view towards increased neutron generation, enhanced reproducibility, and decreased size and energy requirements.
{"title":"Development of Dense Plasma Foci as Advanced Neutron Sources at LLNL","authors":"A. Povilus, Y. Podpaly, L. Cooper, B. Shaw, S. Chapman, E. Koh, S. Falabella, A. Schmidt","doi":"10.1109/PLASMA.2017.8496271","DOIUrl":"https://doi.org/10.1109/PLASMA.2017.8496271","url":null,"abstract":"The dense plasma focus (DPF) is a z-pinch device that starts as a coaxial plasma railgun and ends in an implosion phase. DPF's historically were developed as thermonuclear devices. When used with deuterium and tritium gases a DPF can be used to produce neutrons; however, in operation, DPF's often suffered from inconsistent behavior, and the mechanisms driving the neutron production were poorly understood. Using kinetic modeling techniques recently developed at LLNL, we have gained insight into the mechanisms that lead to particle acceleration in the pinch region and can make informed design decisions for optimizing DPF behavior, from sub-kilojoule to mega-joule scale devices. Experimental DPF platforms at LLNL also serve to validate the behaviors seen in simulations and improve device performance with a view towards increased neutron generation, enhanced reproducibility, and decreased size and energy requirements.","PeriodicalId":145705,"journal":{"name":"2017 IEEE International Conference on Plasma Science (ICOPS)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133589753","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 : 2017-05-01DOI: 10.1109/PLASMA.2017.8496133
K. Martus, Jashri Menon
A recent application of plasma jets has involved the healing of wounds in the tadpole species Xenopus laevis 1. The indirect application of the plasma to the amputated tail of the tadpole produced a faster rate of growth, elevated reactive oxygen species in the cellular structures, and an increase in antioxidant enzymes in the regenerate compared to that of the untreated control. The plasma exposure accelerated the dynamics of the wound healing and tail regeneration through its effects on cell proliferation and differentiation, as well as, angiogenesis mediated through reactive oxygen signaling. The discharge source operated with high purity Helium gas at a flow rate of 50sccm that passed through a ¼” quartz tube. A copper electrode was attached to the outer surface of the tube at a point 5.0cm from the end of the tube. Attached to the electrode was an AC power supply operating at 32kHz and 12kV. The system was operated in a regime such that the discharge was restricted to the flow region between the electrode and the exit aperture of the tube. The profiles of the emissions features were measured using a high-resolution spectrometer coupled to an CCD detector. The spectra indicated that molecular nitrogen was present within the tube in both the neutral and ionized states. OH emissions, in the wavelength region between 300–315nm, were observed inside the tube and extending outside of the quartz tube. The emission profile of the Second Positive Systems was used to calculate the vibrational temperature and it was found to be 375±50K. The rotational temperature was determined from a fitting of the Second Positive System transition at 337nm to a Boltzmann distribution and it was found to be 375±50K. The current was measured by monitoring the ground connection from a metal plate that was placed adjacent to the exit aperture of the quartz tube using a current transformer. When the system was powered without a plasma the signal consisted of a sinusoidal wave having an amplitude of less than 0.5mA at a frequency that matched the driving voltage (32kHz). When the plasma was “on” the signal consisted of an additional component superimposed on the sinusoidal wave. The additional component was a short duration (1 μs) positive current pulse (0.75mA) that appeared approximately at the time the high voltage reached its maximum value. The height of this current pulse decreased with distance from the exit aperture of the quartz tube.
{"title":"Charaterization Of A Plasma Source Used To Accelerate Wound Healing Of The Tadpole Xenopus Laevis*","authors":"K. Martus, Jashri Menon","doi":"10.1109/PLASMA.2017.8496133","DOIUrl":"https://doi.org/10.1109/PLASMA.2017.8496133","url":null,"abstract":"A recent application of plasma jets has involved the healing of wounds in the tadpole species Xenopus laevis 1. The indirect application of the plasma to the amputated tail of the tadpole produced a faster rate of growth, elevated reactive oxygen species in the cellular structures, and an increase in antioxidant enzymes in the regenerate compared to that of the untreated control. The plasma exposure accelerated the dynamics of the wound healing and tail regeneration through its effects on cell proliferation and differentiation, as well as, angiogenesis mediated through reactive oxygen signaling. The discharge source operated with high purity Helium gas at a flow rate of 50sccm that passed through a ¼” quartz tube. A copper electrode was attached to the outer surface of the tube at a point 5.0cm from the end of the tube. Attached to the electrode was an AC power supply operating at 32kHz and 12kV. The system was operated in a regime such that the discharge was restricted to the flow region between the electrode and the exit aperture of the tube. The profiles of the emissions features were measured using a high-resolution spectrometer coupled to an CCD detector. The spectra indicated that molecular nitrogen was present within the tube in both the neutral and ionized states. OH emissions, in the wavelength region between 300–315nm, were observed inside the tube and extending outside of the quartz tube. The emission profile of the Second Positive Systems was used to calculate the vibrational temperature and it was found to be 375±50K. The rotational temperature was determined from a fitting of the Second Positive System transition at 337nm to a Boltzmann distribution and it was found to be 375±50K. The current was measured by monitoring the ground connection from a metal plate that was placed adjacent to the exit aperture of the quartz tube using a current transformer. When the system was powered without a plasma the signal consisted of a sinusoidal wave having an amplitude of less than 0.5mA at a frequency that matched the driving voltage (32kHz). When the plasma was “on” the signal consisted of an additional component superimposed on the sinusoidal wave. The additional component was a short duration (1 μs) positive current pulse (0.75mA) that appeared approximately at the time the high voltage reached its maximum value. The height of this current pulse decreased with distance from the exit aperture of the quartz tube.","PeriodicalId":145705,"journal":{"name":"2017 IEEE International Conference on Plasma Science (ICOPS)","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133909257","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 : 2017-05-01DOI: 10.1109/PLASMA.2017.8496230
Kong Fanrong, Nie Qiuyue, Sun Yufei, Zhang Zhen, Xiaogang Wang, Jiang Bin-hao
The technology of antenna miniaturization and electromagnetic radiation enhancement has been a hot topic in recent years. And numerous novel methods and techniques have been proposed and investigated towards the future generation of compact antennas with wide-range requests. The application of plasma, a typical metamaterial with negative permittivity, provided a new approach to improve the efficiency of the antenna radiation on communication [1, 2]. In this paper, to further research the technology based on modulation and enhancement effects of sub-wavelength plasma structures on radio frequency (RF) electromagnetic radiation, the numerical simulation and corresponding experiment have been conducted. Firstly, a numerical model based on multi physics simulation software Comsol Multiphysics was built to reveal the enhancement law and mechanism of sub-wavelength plasma structures on RF electromagnetic radiation by changing the shape of plasma, the density distribution of plasma and the collision frequency of plasma. Correspondingly, an inductively coupled plasma was applied to provide appropriate sub-wavelength plasma structures aiming at enhancing RF electromagnetic radiation of an omnidirectional ellipse dipole antenna. And a significant enhancement of electromagnetic radiation up to $5 sim 10$ dB higher than the free-space radiation on RF antenna signals of $sim 1$ GHz or higher has been observed, which exhibited a good agreement with the numerical simulation results, the absolute bandwidth reached 170 MHz and the fractional bandwidth reached 17.6%. The results and their discussions have demonstrated the feasibility of the RF radiation enhancement by subwavelength plasma structures in an applicable range of RF bands, such as L-band, and a promising potential in the field of antenna radiation modulation and enhancement.
{"title":"Studies On The Plasma-Added Intensification Of Gigahertz Radio Frequency Signals","authors":"Kong Fanrong, Nie Qiuyue, Sun Yufei, Zhang Zhen, Xiaogang Wang, Jiang Bin-hao","doi":"10.1109/PLASMA.2017.8496230","DOIUrl":"https://doi.org/10.1109/PLASMA.2017.8496230","url":null,"abstract":"The technology of antenna miniaturization and electromagnetic radiation enhancement has been a hot topic in recent years. And numerous novel methods and techniques have been proposed and investigated towards the future generation of compact antennas with wide-range requests. The application of plasma, a typical metamaterial with negative permittivity, provided a new approach to improve the efficiency of the antenna radiation on communication [1, 2]. In this paper, to further research the technology based on modulation and enhancement effects of sub-wavelength plasma structures on radio frequency (RF) electromagnetic radiation, the numerical simulation and corresponding experiment have been conducted. Firstly, a numerical model based on multi physics simulation software Comsol Multiphysics was built to reveal the enhancement law and mechanism of sub-wavelength plasma structures on RF electromagnetic radiation by changing the shape of plasma, the density distribution of plasma and the collision frequency of plasma. Correspondingly, an inductively coupled plasma was applied to provide appropriate sub-wavelength plasma structures aiming at enhancing RF electromagnetic radiation of an omnidirectional ellipse dipole antenna. And a significant enhancement of electromagnetic radiation up to $5 sim 10$ dB higher than the free-space radiation on RF antenna signals of $sim 1$ GHz or higher has been observed, which exhibited a good agreement with the numerical simulation results, the absolute bandwidth reached 170 MHz and the fractional bandwidth reached 17.6%. The results and their discussions have demonstrated the feasibility of the RF radiation enhancement by subwavelength plasma structures in an applicable range of RF bands, such as L-band, and a promising potential in the field of antenna radiation modulation and enhancement.","PeriodicalId":145705,"journal":{"name":"2017 IEEE International Conference on Plasma Science (ICOPS)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134018073","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 : 2017-05-01DOI: 10.1109/PLASMA.2017.8496273
S. Nawaz, H. Rhee, D. H. Kim, S. Yoon
Summary form only given. Inductively coupled plasmas (ICP) have attracted widespread interest in semiconductor fabrication processes due to attractive properties including high plasma density and low contamination that are available under low-pressure. We report the characteristics of E-H mode transition changes at various gas mixtures in the pressure controlled chamber. Our discharge chamber, which was designed for photoresist dry-strip process, had 200mm diameter and consisted of three-turn external cylindrical antenna coil which sustained 13.56 MHz RF power through pi-type matching network. Generation of O radical is of great interest for dry-strip process in semiconductor industry in order to remove photoresist (PR) deposited on wafer. Mixture of N2 in the O2 plasma increases portion of O radical due to collision of two molecules 1. It is of interest to evaluate the EH mode transition power at various gas mixture for better understand the process tool. The voltage and current on the coil are measured with a high voltage probe and a current sensor. The preliminary results show that the transition from E to H mode occurs at relatively low power for pure oxygen than pure nitrogen and gas mixture. The energy loss via collision and electron-neutral collision frequency for N2 molecules are greater than O2 which requires higher transition ICP power. Moreover PR strip rate was compared at different gas mixture in order to compare O radical generation. Total PR strip amount was compared for changing the ratio of two gas mixture. The experimental results show the total PR strip amount is increased for mixing N2 among O2 plasma. These results will be considered to operate efficient ICP source and to optimize the process condition for PR dry-strip process.
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