Pub Date : 2006-11-01DOI: 10.1109/MEGAGUSS.2006.4530685
V. Demidov, V. Selemir
Megaampere pulsed currents with a rise time of 0.1-1 mus are required for fusion studies. Use of one or several stages of the current pulse sharpening should be used at such pulses formation using inductive systems of energy storage. In this case large energy losses take place. According to estimations, to realize technical projects of fusion reaction ignition the inductive sources with the stored energy of tens and hundreds megajoules are required. In RFNC-VNIIEF during the last 30 years devices for fusion studies are based on the systems with explosive magnetic flux compression - explosive magnetic generators (EMG). In the paper we consider high-power disk EMG for EMIR complex, intended for soft x-ray radiation generation of 10-megajoule level. Also, the paper presents experimental results with electric-exploded and explosive current opening switches.
{"title":"Explosive Pulsed Power for Controlled Fusion","authors":"V. Demidov, V. Selemir","doi":"10.1109/MEGAGUSS.2006.4530685","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530685","url":null,"abstract":"Megaampere pulsed currents with a rise time of 0.1-1 mus are required for fusion studies. Use of one or several stages of the current pulse sharpening should be used at such pulses formation using inductive systems of energy storage. In this case large energy losses take place. According to estimations, to realize technical projects of fusion reaction ignition the inductive sources with the stored energy of tens and hundreds megajoules are required. In RFNC-VNIIEF during the last 30 years devices for fusion studies are based on the systems with explosive magnetic flux compression - explosive magnetic generators (EMG). In the paper we consider high-power disk EMG for EMIR complex, intended for soft x-ray radiation generation of 10-megajoule level. Also, the paper presents experimental results with electric-exploded and explosive current opening switches.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127068110","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 : 2006-11-01DOI: 10.1109/MEGAGUSS.2006.4530656
F. Herlach
The generation and use of pulsed magnetic fields are surveyed from the very beginning with the work of P. Kapitza. The survey is focused on fields in the megagauss range, including non-destructive fields above half a megagauss where the development is now aimed at approaching the 100-tesla limit. In the open literature, megagauss fields were first reported from an experiment with a capacitor-driven single turn coil. This was followed by explosive-driven magnetic flux compression that consistently generates the highest fields. Electromagnetic flux compression was developed from a modest beginning into a research instrument. By far the largest part of scientific research in megagauss fields was accomplished with the single turn coil after it had been developed into a reliable and practical research instrument. The potential for future development of the different techniques and of some novel techniques is indicated.
{"title":"The Generation and Use of Pulsed Magnetic Fields","authors":"F. Herlach","doi":"10.1109/MEGAGUSS.2006.4530656","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530656","url":null,"abstract":"The generation and use of pulsed magnetic fields are surveyed from the very beginning with the work of P. Kapitza. The survey is focused on fields in the megagauss range, including non-destructive fields above half a megagauss where the development is now aimed at approaching the 100-tesla limit. In the open literature, megagauss fields were first reported from an experiment with a capacitor-driven single turn coil. This was followed by explosive-driven magnetic flux compression that consistently generates the highest fields. Electromagnetic flux compression was developed from a modest beginning into a research instrument. By far the largest part of scientific research in megagauss fields was accomplished with the single turn coil after it had been developed into a reliable and practical research instrument. The potential for future development of the different techniques and of some novel techniques is indicated.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130137498","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 : 2006-11-01DOI: 10.1109/MEGAGUSS.2006.4530709
S. Krivosheev, G. Shneerson
Experiments on studying materials properties demand not only full information on the parameters of the acting loading pulse, but also the use of such loading conditions that allow us to carry out the analytical analysis of the deflected mode. It is obvious that the complexity and multifactority of the destruction process is aggravated in dynamic loading with occurrence of additional parameter, namely the shape and duration of a loading pulse. To study the destruction of faultless samples in dynamics the scabbing loading conditions are traditionally used. Scabbing loading allows carrying out pulse tensile pressure produced by a stretching wave, arising due to reflection of the compression wave from a free end face of the sample. In such situation for destruction, except for the characteristics of a material, the amplitude, the form, and duration of the pulse are responsible for the destruction.
{"title":"The Use of Pressure Pulses Arising from the Creation of Strong Pulsed Magnetic Fields for the Study of the Dynamic Strength of Materials","authors":"S. Krivosheev, G. Shneerson","doi":"10.1109/MEGAGUSS.2006.4530709","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530709","url":null,"abstract":"Experiments on studying materials properties demand not only full information on the parameters of the acting loading pulse, but also the use of such loading conditions that allow us to carry out the analytical analysis of the deflected mode. It is obvious that the complexity and multifactority of the destruction process is aggravated in dynamic loading with occurrence of additional parameter, namely the shape and duration of a loading pulse. To study the destruction of faultless samples in dynamics the scabbing loading conditions are traditionally used. Scabbing loading allows carrying out pulse tensile pressure produced by a stretching wave, arising due to reflection of the compression wave from a free end face of the sample. In such situation for destruction, except for the characteristics of a material, the amplitude, the form, and duration of the pulse are responsible for the destruction.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132623659","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 : 2006-11-01DOI: 10.1109/MEGAGUSS.2006.4530681
E. Kojima, S. Takeyama
Electro-magnetic flux compression (EMFC) is one of the most powerful methods to generate mega-gauss magnetic fields. The EMFC facility at ISSP has attained the world record for indoor generation of magnetic fields. We have recently implemented successful improvements to generate a higher field with less energy injection and with more simplified coil preparation processes. We have changed the structure and the materials of the primary coil. We have tested the new coil system and succeeded in generating fields up to 350 T with 1 MJ, 470 T with 2 MJ and 520 T with 3 MJ. Hence, electro-magnetic energy transfer efficiency has been increased a great deal. The liner implosive motion was much improved with good cylindrical symmetry. A simple calculation has given insight into the relations between the current density distribution of a primary coil and the shape of the liner during the process of the implosion.
{"title":"Newly Designed Destructive Magnetic Coils for Mega-Gauss Fields at ISSP","authors":"E. Kojima, S. Takeyama","doi":"10.1109/MEGAGUSS.2006.4530681","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530681","url":null,"abstract":"Electro-magnetic flux compression (EMFC) is one of the most powerful methods to generate mega-gauss magnetic fields. The EMFC facility at ISSP has attained the world record for indoor generation of magnetic fields. We have recently implemented successful improvements to generate a higher field with less energy injection and with more simplified coil preparation processes. We have changed the structure and the materials of the primary coil. We have tested the new coil system and succeeded in generating fields up to 350 T with 1 MJ, 470 T with 2 MJ and 520 T with 3 MJ. Hence, electro-magnetic energy transfer efficiency has been increased a great deal. The liner implosive motion was much improved with good cylindrical symmetry. A simple calculation has given insight into the relations between the current density distribution of a primary coil and the shape of the liner during the process of the implosion.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121270000","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 : 2006-11-01DOI: 10.1109/MEGAGUSS.2006.4530696
S. Shkuratov, E. Talantsev, J. Baird, L. Altgilbers, A. Stults
Ultracompact explosive-driven shock wave ferroelectric generators (FEGs) were used as autonomous primary power sources for charging capacitor banks of different capacitance. The FEGs utilized longitudinal (when the shock wave propagates along the polarization vector P) shock wave depolarization of Pb(Zr52Ti48)O3 (PZT) polycrystalline ferroelectric ceramic. PZT disks having diameters ranging from 25 to 27 mm and three different thicknesses: 0.65, 2.1, and 5.1 mm. It was experimentally shown that during the charging process the FEGs were capable of producing pulsed power with peak amplitudes up to 0.3 MW. Results for charging voltage, electric charge transfer and energy transfer from the FEGs to the capacitor banks of capacitances CL = 2.25, 4.5, 9.0, 18.0, and 36.0 nF are presented. Analysis of the experimental data shows that the maximum energy transfer from the FEG to the capacitor bank differs for each type of ferroelectric energy-carrying element, and is dependent upon the capacitance of the capacitor banks.
{"title":"Pulse Charging of Capacitor Bank by Explosive-Driven Shock Wave Ferroelectric Generator","authors":"S. Shkuratov, E. Talantsev, J. Baird, L. Altgilbers, A. Stults","doi":"10.1109/MEGAGUSS.2006.4530696","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530696","url":null,"abstract":"Ultracompact explosive-driven shock wave ferroelectric generators (FEGs) were used as autonomous primary power sources for charging capacitor banks of different capacitance. The FEGs utilized longitudinal (when the shock wave propagates along the polarization vector P) shock wave depolarization of Pb(Zr52Ti48)O3 (PZT) polycrystalline ferroelectric ceramic. PZT disks having diameters ranging from 25 to 27 mm and three different thicknesses: 0.65, 2.1, and 5.1 mm. It was experimentally shown that during the charging process the FEGs were capable of producing pulsed power with peak amplitudes up to 0.3 MW. Results for charging voltage, electric charge transfer and energy transfer from the FEGs to the capacitor banks of capacitances CL = 2.25, 4.5, 9.0, 18.0, and 36.0 nF are presented. Analysis of the experimental data shows that the maximum energy transfer from the FEG to the capacitor bank differs for each type of ferroelectric energy-carrying element, and is dependent upon the capacitance of the capacitor banks.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133012291","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 : 2006-11-01DOI: 10.1109/MEGAGUSS.2006.4530695
S. Shkuratov, E. Talantsev, J. Baird, L. Altgilbers, A. Stults
A new concept for constructing explosive-driven primary power sources is proposed. The power source is designed as a sequence of identical elementary miniature explosive-driven primary power cells that connect to each other in series or in parallel. Each explosive-driven cell contains a miniature ferromagnetic generator (FMG) based on the effect of transverse shock-wave demagnetization of an Nd2Fe14B hard ferromagnet. Experimental results are presented for high-voltage system utilizing FMGs containing 12.9 cm3 ferromagnet energy-carrying elements. The developed two-cell system produces a high voltage pulse with an amplitude of 32 kV and rise time of 3.5 mus.
{"title":"A New Concept of Explosive Pulsed Power: Design of Macro Primary Power Sources Based on Elementary Miniature Shock-Wave Ferromagnetic Cells","authors":"S. Shkuratov, E. Talantsev, J. Baird, L. Altgilbers, A. Stults","doi":"10.1109/MEGAGUSS.2006.4530695","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530695","url":null,"abstract":"A new concept for constructing explosive-driven primary power sources is proposed. The power source is designed as a sequence of identical elementary miniature explosive-driven primary power cells that connect to each other in series or in parallel. Each explosive-driven cell contains a miniature ferromagnetic generator (FMG) based on the effect of transverse shock-wave demagnetization of an Nd2Fe14B hard ferromagnet. Experimental results are presented for high-voltage system utilizing FMGs containing 12.9 cm3 ferromagnet energy-carrying elements. The developed two-cell system produces a high voltage pulse with an amplitude of 32 kV and rise time of 3.5 mus.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121622302","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 : 2006-11-01DOI: 10.1109/MEGAGUSS.2006.4530697
S. Shkuratov, E. Talantsev, J. Baird, L. Altgilbers, A. Stults
A new design idea for a compact, autonomous, completely explosive pulsed power system is proposed. The system is based on the shock wave ferromagnetic generator (FMG) as a primary power source and a loop magnetic flux compression generator (LFCG) as a pulsed power amplifier. The FMG primary power source utilizes the effect of transverse shock wave demagnetization of Nd2Fe14B high-energy hard ferromagnets to produce the seed current. Results are presented of an experimental study and digital simulation of operation of the FMG-LFCG system.
{"title":"New Concept for Constructing an Autonomous Completely Explosive Pulsed Power System: Transverse Shock Wave Ferromagnetic Primary Power Source and Loop Flux Compression Amplifier","authors":"S. Shkuratov, E. Talantsev, J. Baird, L. Altgilbers, A. Stults","doi":"10.1109/MEGAGUSS.2006.4530697","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530697","url":null,"abstract":"A new design idea for a compact, autonomous, completely explosive pulsed power system is proposed. The system is based on the shock wave ferromagnetic generator (FMG) as a primary power source and a loop magnetic flux compression generator (LFCG) as a pulsed power amplifier. The FMG primary power source utilizes the effect of transverse shock wave demagnetization of Nd2Fe14B high-energy hard ferromagnets to produce the seed current. Results are presented of an experimental study and digital simulation of operation of the FMG-LFCG system.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125420342","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 : 2006-11-01DOI: 10.1109/MEGAGUSS.2006.4530690
A. Buyko
The paper briefly discusses the problem setup for a 1D code that offers wide functionality for simulating electrophysical facilities with different ponderomotive units (PU) intended for studies in the area of high energy density physics and materials properties. 1D magneto-hydrodynamic approximation is used, which also enables simulations of essentially two-dimensional units, such as disc explosive magnetic generators (DEMG), quasi-spherical liners etc. Examples of such simulations are given.
{"title":"Disc Explosive Magnetic Generator and Quasi-Spherical Liner Simulations with a 1D Code","authors":"A. Buyko","doi":"10.1109/MEGAGUSS.2006.4530690","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530690","url":null,"abstract":"The paper briefly discusses the problem setup for a 1D code that offers wide functionality for simulating electrophysical facilities with different ponderomotive units (PU) intended for studies in the area of high energy density physics and materials properties. 1D magneto-hydrodynamic approximation is used, which also enables simulations of essentially two-dimensional units, such as disc explosive magnetic generators (DEMG), quasi-spherical liners etc. Examples of such simulations are given.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134146626","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 : 2006-11-01DOI: 10.1109/MEGAGUSS.2006.4530679
J. Wosnitza, A. Bianchi, T. Herrmannsdorfer, S. Zherlitsyn, S. Zvyagin
The recent progress made at and the status quo of the Dresden High Magnetic Field Laboratory (Hochfeld-Magnetlabor Dresden = HLD) is reported. This laboratory, presently under construction at the research center (Forschungszentrum) Dresden-Rossendorf, is planned to open as user facility in 2007 offering access to various pulsed-field magnets. Besides introducing the installed capacitive energy supply at the HLD, the pulsed-magnet designs are discussed in some detail. The experimental techniques that are routinely running at the HLD and the additional ones being set up, are summarized. First scientific results are highlighted.
{"title":"Recent Developments at the Dresden High Magnetic Field Laboratory","authors":"J. Wosnitza, A. Bianchi, T. Herrmannsdorfer, S. Zherlitsyn, S. Zvyagin","doi":"10.1109/MEGAGUSS.2006.4530679","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530679","url":null,"abstract":"The recent progress made at and the status quo of the Dresden High Magnetic Field Laboratory (Hochfeld-Magnetlabor Dresden = HLD) is reported. This laboratory, presently under construction at the research center (Forschungszentrum) Dresden-Rossendorf, is planned to open as user facility in 2007 offering access to various pulsed-field magnets. Besides introducing the installed capacitive energy supply at the HLD, the pulsed-magnet designs are discussed in some detail. The experimental techniques that are routinely running at the HLD and the additional ones being set up, are summarized. First scientific results are highlighted.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132568521","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 : 2006-11-01DOI: 10.1109/MEGAGUSS.2006.4530686
G. Kiuttu, J. Chase, D. Chato
Helical explosively driven magnetic flux compression generators (FCGs) have been intensively investigated for more than four decades, because of their ability to amplify electrical current and magnetic energy with high gain and relatively small size. Whereas coaxial-geometry FCGs have lent themselves to reasonably accurate modeling, helical FCGs have always been considered "anomalously lossy," with calculated performance invariably exceeding observed performance - often by factors of two or more in peak output current. With the advent of the analytically derived Kiuttu contact resistance model (KCRM), it has become possible to approximately account for the losses in the vicinity of the contact point between armature and stator without resorting to any empirical tuning factors. Such factors have generally been required by other modeling and simulation codes to achieve agreement with experimental data. Since its introduction, the KCRM has been extended to include the region immediately in front of the contact point as well, thus improving its accuracy. Another key element in modeling the performance of helical FCGs is proper accounting of the proximity effect between adjacent turns of the solenoidal stator winding. This effect alters the magnetic field and current density distributions from their isolated, approximately locally uniform distributions, leading to an effective increase in flux diffusion rates. In order to quantitatively assess this effect, we have run a number of two- dimensional quasi-magnetostatic simulations for varying stator geometries and extracted simplified approximations that can be used in one-dimensional diffusion calculations. We have also examined the details of the circuit model definition (i.e., flux-based from Faraday's Law, or the diffusion equation, and energy-based from Poynting's Theorem). The generator equation, derived from the circuit model, involves lumped-element approximations for resistance and inductance, and we have shown that the combination of inductance and resistance, which yields experimental current and time derivative of current, is not unique, and that each lumped element must be consistently defined. We have incorporated these various models and effects into the CAGEN (1&1/2-D) modeling code. As a result, we have been able to accurately calculate the performance of a wide variety of FCGs without using any additional adjustment factors. Representative results, as well as descriptions of the models, will be presented.
{"title":"Recent Advances in Modeling Helical FCGS","authors":"G. Kiuttu, J. Chase, D. Chato","doi":"10.1109/MEGAGUSS.2006.4530686","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530686","url":null,"abstract":"Helical explosively driven magnetic flux compression generators (FCGs) have been intensively investigated for more than four decades, because of their ability to amplify electrical current and magnetic energy with high gain and relatively small size. Whereas coaxial-geometry FCGs have lent themselves to reasonably accurate modeling, helical FCGs have always been considered \"anomalously lossy,\" with calculated performance invariably exceeding observed performance - often by factors of two or more in peak output current. With the advent of the analytically derived Kiuttu contact resistance model (KCRM), it has become possible to approximately account for the losses in the vicinity of the contact point between armature and stator without resorting to any empirical tuning factors. Such factors have generally been required by other modeling and simulation codes to achieve agreement with experimental data. Since its introduction, the KCRM has been extended to include the region immediately in front of the contact point as well, thus improving its accuracy. Another key element in modeling the performance of helical FCGs is proper accounting of the proximity effect between adjacent turns of the solenoidal stator winding. This effect alters the magnetic field and current density distributions from their isolated, approximately locally uniform distributions, leading to an effective increase in flux diffusion rates. In order to quantitatively assess this effect, we have run a number of two- dimensional quasi-magnetostatic simulations for varying stator geometries and extracted simplified approximations that can be used in one-dimensional diffusion calculations. We have also examined the details of the circuit model definition (i.e., flux-based from Faraday's Law, or the diffusion equation, and energy-based from Poynting's Theorem). The generator equation, derived from the circuit model, involves lumped-element approximations for resistance and inductance, and we have shown that the combination of inductance and resistance, which yields experimental current and time derivative of current, is not unique, and that each lumped element must be consistently defined. We have incorporated these various models and effects into the CAGEN (1&1/2-D) modeling code. As a result, we have been able to accurately calculate the performance of a wide variety of FCGs without using any additional adjustment factors. Representative results, as well as descriptions of the models, will be presented.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"983 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133001685","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：