Y. Shimabukuro, M. Ichikawa, M. Murayama, G. Saquilayan, A. Kojima, H. Tobari, M. Kashiwagi
A novel Eclair-shaped filter magnetic field with no primary electron leakage has been proposed to reduce the co-extracted electrons and improve the spatial uniformity of negative ion production. A primary electron analysis was conducted to clarify its spatial distribution and the issue of current magnetic field configuration because the experimental data imply that the negative ion population is low on the edge segments due to the many primary electrons around there. A simulation study revealed that the low capability of electron confinement at the KAMABOKO source’s edge region due to the localized magnetically weak points induces the primary electron leakage, which causes high co-extracted electron current and negative ion non-uniformity. Calculation results showed a new design index that contributes to the complete suppression of primary electron leakage to the extraction region with a permanent magnet connection angle of 108 degrees or more. The Eclair-shaped ion source has been designed based upon the obtained index about the connection angle to realize the ideal magnetic configuration without primary electron leakage to the extraction region.
{"title":"Primary electron analysis to improve the negative ion uniformity toward ITER-class long pulse and high-power negative ion sources","authors":"Y. Shimabukuro, M. Ichikawa, M. Murayama, G. Saquilayan, A. Kojima, H. Tobari, M. Kashiwagi","doi":"10.1063/5.0057507","DOIUrl":"https://doi.org/10.1063/5.0057507","url":null,"abstract":"A novel Eclair-shaped filter magnetic field with no primary electron leakage has been proposed to reduce the co-extracted electrons and improve the spatial uniformity of negative ion production. A primary electron analysis was conducted to clarify its spatial distribution and the issue of current magnetic field configuration because the experimental data imply that the negative ion population is low on the edge segments due to the many primary electrons around there. A simulation study revealed that the low capability of electron confinement at the KAMABOKO source’s edge region due to the localized magnetically weak points induces the primary electron leakage, which causes high co-extracted electron current and negative ion non-uniformity. Calculation results showed a new design index that contributes to the complete suppression of primary electron leakage to the extraction region with a permanent magnet connection angle of 108 degrees or more. The Eclair-shaped ion source has been designed based upon the obtained index about the connection angle to realize the ideal magnetic configuration without primary electron leakage to the extraction region.","PeriodicalId":21797,"journal":{"name":"SEVENTH INTERNATIONAL SYMPOSIUM ON NEGATIVE IONS, BEAMS AND SOURCES (NIBS 2020)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76304928","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}
Fei-Long Song, G. Zou, Dong Li, C. Zuo, Dezhi Chen, Guangjiu Lei
A negative ion source for the Neutral Beam Injection (NBI) system of China Fusion Engineering Test Reactor (CFETR) is under development in the Southwestern Institute of Physics. The aim is to extract an H– beam of 20 A for a pulse duration of 3600 s at an energy of 200 keV. In this work, the beam optics of the source is investigated with a single beamlet model in the COMSOL environment. The effects of varying the main electromagnetic parameters are studied. The boundary between plasma and beam, namely the meniscus, is calculated with a self-consistent method. The optimal condition at which the beam has a minimum divergence angle is found. Beam divergence is within limits. The magnetic field produced by permanent magnets in the extraction grid is verified to deflect co-extracted electrons effectively, while inducing a slight offset of the ion beam. As a conclusion, the system is capable to operate as required.
{"title":"Numerical simulation of beam extraction and optics of an NBI negative ion source","authors":"Fei-Long Song, G. Zou, Dong Li, C. Zuo, Dezhi Chen, Guangjiu Lei","doi":"10.1063/5.0058286","DOIUrl":"https://doi.org/10.1063/5.0058286","url":null,"abstract":"A negative ion source for the Neutral Beam Injection (NBI) system of China Fusion Engineering Test Reactor (CFETR) is under development in the Southwestern Institute of Physics. The aim is to extract an H– beam of 20 A for a pulse duration of 3600 s at an energy of 200 keV. In this work, the beam optics of the source is investigated with a single beamlet model in the COMSOL environment. The effects of varying the main electromagnetic parameters are studied. The boundary between plasma and beam, namely the meniscus, is calculated with a self-consistent method. The optimal condition at which the beam has a minimum divergence angle is found. Beam divergence is within limits. The magnetic field produced by permanent magnets in the extraction grid is verified to deflect co-extracted electrons effectively, while inducing a slight offset of the ion beam. As a conclusion, the system is capable to operate as required.","PeriodicalId":21797,"journal":{"name":"SEVENTH INTERNATIONAL SYMPOSIUM ON NEGATIVE IONS, BEAMS AND SOURCES (NIBS 2020)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79756245","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}
The production of Ordinary Portland Cement (OPC) emits CO2 into the atmosphere. Fly ash, which is a by-product obtained from coal industry, is introduced to replace OPC used in the concrete. It is rich in silicate gel with alkaline solution to produce good concrete. Increase in fly ash fineness enhances the compressive strength and reduces the porosity. In the modern society, the urbanization process has extensively exploited sand from rivers and mountains. The paper presents the flexural behavior of Geopolymer Concrete (GPC) beams and columns of M 30 grade replaced by manufactured sand as replacement of river sand and compares the same with control cement concrete elements and geopolymer concrete elements. The beam size of 150*150 mm and column size 150*150 is cast over an effective span of 1,200 mm and tested for failure under static loads. The load displacement responses and stress-strain analyss of the GPC structural elements with manufactured sand are obtained and compared with regular GPC and conventional concrete elements. The results imply that there is an increase in flexural strength, service load and peak load of GPC elements with manufactured sand.
{"title":"Manufactured sand effect on flexural behavior of geopolymer RCC structural elements","authors":"P. Bhavana, T. Srinivas","doi":"10.1063/5.0058556","DOIUrl":"https://doi.org/10.1063/5.0058556","url":null,"abstract":"The production of Ordinary Portland Cement (OPC) emits CO2 into the atmosphere. Fly ash, which is a by-product obtained from coal industry, is introduced to replace OPC used in the concrete. It is rich in silicate gel with alkaline solution to produce good concrete. Increase in fly ash fineness enhances the compressive strength and reduces the porosity. In the modern society, the urbanization process has extensively exploited sand from rivers and mountains. The paper presents the flexural behavior of Geopolymer Concrete (GPC) beams and columns of M 30 grade replaced by manufactured sand as replacement of river sand and compares the same with control cement concrete elements and geopolymer concrete elements. The beam size of 150*150 mm and column size 150*150 is cast over an effective span of 1,200 mm and tested for failure under static loads. The load displacement responses and stress-strain analyss of the GPC structural elements with manufactured sand are obtained and compared with regular GPC and conventional concrete elements. The results imply that there is an increase in flexural strength, service load and peak load of GPC elements with manufactured sand.","PeriodicalId":21797,"journal":{"name":"SEVENTH INTERNATIONAL SYMPOSIUM ON NEGATIVE IONS, BEAMS AND SOURCES (NIBS 2020)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88715015","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}
In the agricultural industry there’s a necessity for a technology which is more easily understood and implemented by the farmers. machineswhich require very less effort and less time with low cost are required for success in the field of agriculture. Traditional methods are still followed within the field of agriculture, which are outdated in the current world of technology. There is a huge demand for automation in various fields of agriculture. This project includesboth design and fabrication of an Autonomous Agricultural Robot which helps the farmer in different agricultural operations like pesticide spraying to Inspection, control weeds, and material handling. This robot is equipped with four wheels which are independently connected to four L type geared dc motors. These motors are connected to a battery which is charged using a solar panel. This robot uses a Raspberry pi as a main controller which reacts as per the data received from the camera and ultrasonic sensors and whole system is operated us ing a mobile application. Thus, this robot completely automates the field monitoring by moving in the desired route map to follow which is given as a input to the controller using GPS technology.
{"title":"Design and fabrication of a solar powered autonomous agricultural robot","authors":"B. V. Naik, R. Goud","doi":"10.1063/5.0057867","DOIUrl":"https://doi.org/10.1063/5.0057867","url":null,"abstract":"In the agricultural industry there’s a necessity for a technology which is more easily understood and implemented by the farmers. machineswhich require very less effort and less time with low cost are required for success in the field of agriculture. Traditional methods are still followed within the field of agriculture, which are outdated in the current world of technology. There is a huge demand for automation in various fields of agriculture. This project includesboth design and fabrication of an Autonomous Agricultural Robot which helps the farmer in different agricultural operations like pesticide spraying to Inspection, control weeds, and material handling. This robot is equipped with four wheels which are independently connected to four L type geared dc motors. These motors are connected to a battery which is charged using a solar panel. This robot uses a Raspberry pi as a main controller which reacts as per the data received from the camera and ultrasonic sensors and whole system is operated us ing a mobile application. Thus, this robot completely automates the field monitoring by moving in the desired route map to follow which is given as a input to the controller using GPS technology.","PeriodicalId":21797,"journal":{"name":"SEVENTH INTERNATIONAL SYMPOSIUM ON NEGATIVE IONS, BEAMS AND SOURCES (NIBS 2020)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82785005","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}
B. Han, M. Stockli, R. Welton, S. N. MurrayJr., T. Pennisi, C. Stinson, S. Cousineau
The Spallation Neutron Source (SNS) accelerator system includes a 65 keV H- injector, a 2.5 MeV radio frequency quadrupole (RFQ), a 1 GeV linac chain (DTL-CCL-SCL) and an accumulator ring. The H− injector consists of an RF-driven, Cs-enhanced, multi-cusp H− ion source and a compact, two-lens electrostatic low energy beam transport (LEBT). In 2018, a new RFQ was installed in place of the original RFQ along with upgraded ion source support infrastructure. This paper presents the operational performance and some highlights of beam studies with the SNS ion source since the new RFQ was put into operation. SNS routinely operates at 1.4 MW average beam power for three run cycles per year. During the most recently finished run, FY20B, we operated a single source for the entire run spanning ~4 months with a >99.5% availability. A single dose of cesiation was conducted during the ion source startup which yielded ≥54 mA current for the entire run with just few minor adjustments of parameters.
{"title":"Recent performance of the SNS H− ion source with a record long run","authors":"B. Han, M. Stockli, R. Welton, S. N. MurrayJr., T. Pennisi, C. Stinson, S. Cousineau","doi":"10.1063/5.0057408","DOIUrl":"https://doi.org/10.1063/5.0057408","url":null,"abstract":"The Spallation Neutron Source (SNS) accelerator system includes a 65 keV H- injector, a 2.5 MeV radio frequency quadrupole (RFQ), a 1 GeV linac chain (DTL-CCL-SCL) and an accumulator ring. The H− injector consists of an RF-driven, Cs-enhanced, multi-cusp H− ion source and a compact, two-lens electrostatic low energy beam transport (LEBT). In 2018, a new RFQ was installed in place of the original RFQ along with upgraded ion source support infrastructure. This paper presents the operational performance and some highlights of beam studies with the SNS ion source since the new RFQ was put into operation. SNS routinely operates at 1.4 MW average beam power for three run cycles per year. During the most recently finished run, FY20B, we operated a single source for the entire run spanning ~4 months with a >99.5% availability. A single dose of cesiation was conducted during the ion source startup which yielded ≥54 mA current for the entire run with just few minor adjustments of parameters.","PeriodicalId":21797,"journal":{"name":"SEVENTH INTERNATIONAL SYMPOSIUM ON NEGATIVE IONS, BEAMS AND SOURCES (NIBS 2020)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81528240","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}
The generally applied area-based administrations require an exclusive expectation for situating innovation. Presently, indoor positioning has been an extraordinary achievement; notwithstanding, indoor situating innovations are in the beginning phases of advancement. The aim of this study is to design a wireless signal with a distinctive, broadband spectrum in the correct fingerprint based indoor location sensing systems. Although wifi signals are commonly used with signal strength indicators (RSSI) received in indoor location detection, the use of widespread wifi causes a significant mix of signal strength. The use of chaos-based signals for distinctive indoor fingerprinting is recommended using the chaos signals that are noticeable with a low intercept ratio and high bandwidth.
{"title":"Novel approaches for indoor positioning using chaotic signals","authors":"A. Prakash, J. S. Bhanu, Sunitha Devi Bigul","doi":"10.1063/5.0057905","DOIUrl":"https://doi.org/10.1063/5.0057905","url":null,"abstract":"The generally applied area-based administrations require an exclusive expectation for situating innovation. Presently, indoor positioning has been an extraordinary achievement; notwithstanding, indoor situating innovations are in the beginning phases of advancement. The aim of this study is to design a wireless signal with a distinctive, broadband spectrum in the correct fingerprint based indoor location sensing systems. Although wifi signals are commonly used with signal strength indicators (RSSI) received in indoor location detection, the use of widespread wifi causes a significant mix of signal strength. The use of chaos-based signals for distinctive indoor fingerprinting is recommended using the chaos signals that are noticeable with a low intercept ratio and high bandwidth.","PeriodicalId":21797,"journal":{"name":"SEVENTH INTERNATIONAL SYMPOSIUM ON NEGATIVE IONS, BEAMS AND SOURCES (NIBS 2020)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88982801","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}
This paper presents the outcomes on an exploratory program conveyed to investigate the chance of fly ash and alccofine as complete substitution of cement in Geopolymer concrete. GPC mixes were designed in such a way that flyash and alccofine proportions are taken as M1 F100A0, M2 F90A10, M3 F80 A20, M4 F70 A30, M5 F60 A40, M6 F50A50, for which M3 F80A20 is taken as optimum mix based on economic conditions. Experimental programme developed to check the durability properties like Acid attack test (H2SO4), Chloride attack test (HCL), Nitrate attack test (HNO3), Sulphate attack test (Na2SO4), and water absorption test. The compressive strength of Geopolymer concrete and change in mass percentages were indicated by the tests results.
{"title":"Durability tests of alccofine and flyash based GPC","authors":"M. Niveditha, Srikanth Koniki","doi":"10.1063/5.0058500","DOIUrl":"https://doi.org/10.1063/5.0058500","url":null,"abstract":"This paper presents the outcomes on an exploratory program conveyed to investigate the chance of fly ash and alccofine as complete substitution of cement in Geopolymer concrete. GPC mixes were designed in such a way that flyash and alccofine proportions are taken as M1 F100A0, M2 F90A10, M3 F80 A20, M4 F70 A30, M5 F60 A40, M6 F50A50, for which M3 F80A20 is taken as optimum mix based on economic conditions. Experimental programme developed to check the durability properties like Acid attack test (H2SO4), Chloride attack test (HCL), Nitrate attack test (HNO3), Sulphate attack test (Na2SO4), and water absorption test. The compressive strength of Geopolymer concrete and change in mass percentages were indicated by the tests results.","PeriodicalId":21797,"journal":{"name":"SEVENTH INTERNATIONAL SYMPOSIUM ON NEGATIVE IONS, BEAMS AND SOURCES (NIBS 2020)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83307413","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}
BTR code, which is generally used for neutral beamline design and optimization, is applied to calculate the injected beam stopping in plasma, beam ionization and current drive in a fusion neutron source DEMO-FNS. The beam- plasma model implements detailed spatial and angular distributions of the injected beam taking into account the multi- channel injector geometry and operating parameters. The beam ionization incorporates the stopping cross-section fits by Janev-Suzuki. The beam's instant 3D deposition in a plasma is compared for various beam geometries. The beam losses and detailed shine-through images are obtained taking into account beam aberrations in the 3D plasma target. The fast ion current profiles are evaluated with a simple slowing-down procedure. The influence of beam size, beamlet focusing and inner divergence is proved to be essential for beam deposition and current drive efficiency. The aberrations of tangential beam decay in toroidal plasmas lead to beam profile asymmetry, which can be potentially critical for the current drive - especially when thick and divergent beams are injected off-axis.
{"title":"BTR application for beam slowing-down analysis","authors":"E. Dlougach","doi":"10.1063/5.0057500","DOIUrl":"https://doi.org/10.1063/5.0057500","url":null,"abstract":"BTR code, which is generally used for neutral beamline design and optimization, is applied to calculate the injected beam stopping in plasma, beam ionization and current drive in a fusion neutron source DEMO-FNS. The beam- plasma model implements detailed spatial and angular distributions of the injected beam taking into account the multi- channel injector geometry and operating parameters. The beam ionization incorporates the stopping cross-section fits by Janev-Suzuki. The beam's instant 3D deposition in a plasma is compared for various beam geometries. The beam losses and detailed shine-through images are obtained taking into account beam aberrations in the 3D plasma target. The fast ion current profiles are evaluated with a simple slowing-down procedure. The influence of beam size, beamlet focusing and inner divergence is proved to be essential for beam deposition and current drive efficiency. The aberrations of tangential beam decay in toroidal plasmas lead to beam profile asymmetry, which can be potentially critical for the current drive - especially when thick and divergent beams are injected off-axis.","PeriodicalId":21797,"journal":{"name":"SEVENTH INTERNATIONAL SYMPOSIUM ON NEGATIVE IONS, BEAMS AND SOURCES (NIBS 2020)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79376790","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}
Steady-state operation of a fusion neutron source (FNS) will require plasma heating and maintaining the current therein by fast atom beam injection. The DEMO-FNS project assumes the use of six injectors providing additional heating power up to 30 MW at an atomic energy of 500 keV. As a prototype for the DEMO-FNS injector, an injector developed in detail for the ITER project can be used. The overall injector layout may be retained, but changes in individual components will be required due to the difference in beam energy and power. Inside these components, there are very strict restrictions on the magnetic field magnitude: the flux density should be below a certain value along the path of ion movement and even lower in the neutralization region. To achieve these characteristics in an environment with a high scattered field due to the magnetic system of the facility – including the coils of the poloidal and toroidal fields, the central solenoid and the plasma itself – additional shielding of the injectors is required. At this stage, we expect that the proposed design will allow obtainment of the required magnetic field values using only passive shielding. The shield would be formed of a case made of ferromagnetic material with a high magnetic permeability index. An electromagnetic analysis of the effectiveness of such a screen was performed using 3D modeling using the ANSYS code. In addition, the BTR code was used to calculate power loads along the entire injection path length in the obtained magnetic fields conditions, taking into account reionization.
{"title":"Analysis of the DEMO-FNS magnetic field passive reduction and neutral beam injectors shielding methods","authors":"S. Ananyev, E. Dlougach, A. V. Klishchenko","doi":"10.1063/5.0057405","DOIUrl":"https://doi.org/10.1063/5.0057405","url":null,"abstract":"Steady-state operation of a fusion neutron source (FNS) will require plasma heating and maintaining the current therein by fast atom beam injection. The DEMO-FNS project assumes the use of six injectors providing additional heating power up to 30 MW at an atomic energy of 500 keV. As a prototype for the DEMO-FNS injector, an injector developed in detail for the ITER project can be used. The overall injector layout may be retained, but changes in individual components will be required due to the difference in beam energy and power. Inside these components, there are very strict restrictions on the magnetic field magnitude: the flux density should be below a certain value along the path of ion movement and even lower in the neutralization region. To achieve these characteristics in an environment with a high scattered field due to the magnetic system of the facility – including the coils of the poloidal and toroidal fields, the central solenoid and the plasma itself – additional shielding of the injectors is required. At this stage, we expect that the proposed design will allow obtainment of the required magnetic field values using only passive shielding. The shield would be formed of a case made of ferromagnetic material with a high magnetic permeability index. An electromagnetic analysis of the effectiveness of such a screen was performed using 3D modeling using the ANSYS code. In addition, the BTR code was used to calculate power loads along the entire injection path length in the obtained magnetic fields conditions, taking into account reionization.","PeriodicalId":21797,"journal":{"name":"SEVENTH INTERNATIONAL SYMPOSIUM ON NEGATIVE IONS, BEAMS AND SOURCES (NIBS 2020)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79155001","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}
Miral Shah, B. Chaudhury, M. Bandyopadhyay, A. Chakraborty
Low pressure, low-temperature plasma (LTP) with a spatially varying transverse magnetic filter field configuration has a wide range of applications. In such devices, the magnetic field value is low enough that it magnetizes only the electrons and not the ions, and works as an electron filter by limiting the flux of hot electrons. Due to the gradient of the transverse magnetic filter field, the electron cyclotron frequencies are also changing with location and in some places it comes close to different collision frequencies. A parallel 2D-3V Particle-in-Cell Monte Carlo Collision (PIC MCC) kinetic model based code has been developed to study plasma transport in a negative ion source where a spatially varying transverse magnetic filter field is considered in a source geometry similar to that of ROBIN (RF Operated Beam source in INdia). Various collision dependent physical phenomena, having different time scales and length scales are studied. In this article, we are reporting instabilities, observed near the filter field region. It is also observed that the frequencies of those instabilities are close to some of the electronic and ionic collision frequencies which may create resonant phenomena in the magnetic filter region and influence the cross-field transport, and heating.
{"title":"The feasibility of resonance induced instabilities in the magnetic filter region of low temperature plasma based negative ion sources","authors":"Miral Shah, B. Chaudhury, M. Bandyopadhyay, A. Chakraborty","doi":"10.1063/5.0057722","DOIUrl":"https://doi.org/10.1063/5.0057722","url":null,"abstract":"Low pressure, low-temperature plasma (LTP) with a spatially varying transverse magnetic filter field configuration has a wide range of applications. In such devices, the magnetic field value is low enough that it magnetizes only the electrons and not the ions, and works as an electron filter by limiting the flux of hot electrons. Due to the gradient of the transverse magnetic filter field, the electron cyclotron frequencies are also changing with location and in some places it comes close to different collision frequencies. A parallel 2D-3V Particle-in-Cell Monte Carlo Collision (PIC MCC) kinetic model based code has been developed to study plasma transport in a negative ion source where a spatially varying transverse magnetic filter field is considered in a source geometry similar to that of ROBIN (RF Operated Beam source in INdia). Various collision dependent physical phenomena, having different time scales and length scales are studied. In this article, we are reporting instabilities, observed near the filter field region. It is also observed that the frequencies of those instabilities are close to some of the electronic and ionic collision frequencies which may create resonant phenomena in the magnetic filter region and influence the cross-field transport, and heating.","PeriodicalId":21797,"journal":{"name":"SEVENTH INTERNATIONAL SYMPOSIUM ON NEGATIVE IONS, BEAMS AND SOURCES (NIBS 2020)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75121329","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}
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