Pub Date : 2007-06-17DOI: 10.1109/PPPS.2007.4651854
J. Berkery, Q. Marksteiner, M. Hahn, T. Sunn Pedersen, B. D. de Gevigney, P. Brenner, J. M. Mendez
The equilibrium, stability and transport properties of electron plasmas confined on magnetic surfaces in the Columbia Non-neutral Torus are discussed. The equilibrium is characterized by a Poisson-Boltzmann equation. Measured potential and temperature profiles are presented. These plasmas are generally stable but can be destabilized by an ion driven instability that involves the interaction of the ion and electron fluids and has a poloidal mode number of m = 1. The transport of electrons driven by collisions with neutrals is much greater than the neoclassical prediction. A code has been written to follow single particle motion to determine why. Finally, sudden jumps between different equilibria with different transport levels are being investigated.
{"title":"Equilibrium, stability, and transport of electron plasmas in the Columbia Non-neutral Torus","authors":"J. Berkery, Q. Marksteiner, M. Hahn, T. Sunn Pedersen, B. D. de Gevigney, P. Brenner, J. M. Mendez","doi":"10.1109/PPPS.2007.4651854","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4651854","url":null,"abstract":"The equilibrium, stability and transport properties of electron plasmas confined on magnetic surfaces in the Columbia Non-neutral Torus are discussed. The equilibrium is characterized by a Poisson-Boltzmann equation. Measured potential and temperature profiles are presented. These plasmas are generally stable but can be destabilized by an ion driven instability that involves the interaction of the ion and electron fluids and has a poloidal mode number of m = 1. The transport of electrons driven by collisions with neutrals is much greater than the neoclassical prediction. A code has been written to follow single particle motion to determine why. Finally, sudden jumps between different equilibria with different transport levels are being investigated.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115080512","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4651873
V. Kladukhin, S. Kladukhin, S. Khramtsov, N. Kovalev
An approach, which is based on propagation of the overvoltage in the chain of switching-type (threshold) elements, is proposed for development of distributed switches. The process essentially is the interaction of three dividing chains: the main chain is made up of switching-type elements triggered by voltage threshold crossing and two auxiliary chains including capacitive elements. Elements of the main and auxiliary capacitive dividing chains form circuits. Coupling of these circuits ensures propagation of the overvoltage in threshold elements. Switching-type elements, which are located on the switching wave front, form an electric field, whose intensity is two or more times higher than the initial intensity. A sequence switch made as a controlled high-current multi-gap high-pressure switch with a multi-spark nanosecond switching regime is described. Results of its experimental testing are reported. Closing of any threshold element changes the state of scheme, in which the overvoltage on the adjacent threshold elements is at the minimum twice initial voltage.
{"title":"Sequence nanosecond switch","authors":"V. Kladukhin, S. Kladukhin, S. Khramtsov, N. Kovalev","doi":"10.1109/PPPS.2007.4651873","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4651873","url":null,"abstract":"An approach, which is based on propagation of the overvoltage in the chain of switching-type (threshold) elements, is proposed for development of distributed switches. The process essentially is the interaction of three dividing chains: the main chain is made up of switching-type elements triggered by voltage threshold crossing and two auxiliary chains including capacitive elements. Elements of the main and auxiliary capacitive dividing chains form circuits. Coupling of these circuits ensures propagation of the overvoltage in threshold elements. Switching-type elements, which are located on the switching wave front, form an electric field, whose intensity is two or more times higher than the initial intensity. A sequence switch made as a controlled high-current multi-gap high-pressure switch with a multi-spark nanosecond switching regime is described. Results of its experimental testing are reported. Closing of any threshold element changes the state of scheme, in which the overvoltage on the adjacent threshold elements is at the minimum twice initial voltage.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121940185","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4652426
B. Fridman, R. Enikeev
At a small skin depth the electromagnetic field in conductors can be defined by the boundary layer method. The derived asymptotic solution makes it possible to determine the expansion in a series of the voltage drop across massive conductors. In this expansion the first term describes the limiting solution with infinite conductivity and corresponds to self-induction electro-motive force (EMF) of the external magnetic field or voltage drop across external inductance of massive conductors. Asymptotic correction of the first-order approximation corresponds to the fraction of the voltage drop calculated under the impedance boundary conditions on the surface of the conductors. The second-order correction takes into account the curvature of the conductor surface and inhomogeneity of the external magnetic field and varies in time directly as does current in the conductors, i.e. as in the case with voltage drop across a usual resistor. Such approximation establishes the relation between current and voltage drop on massive conductors, which can be included into the Kirchhoff’s equations for analysis and calculation of the transients in the circuits with massive conductors. The purpose of the paper is consideration of the peculiarities of the transients in electrical circuits, the methods of measurement of the massive conductor parameters, as well as the methods of the transients calculations in the time domain, which use the asymptotic representation of the voltage drop on massive conductors.
{"title":"Massive conductor impedance and peculiarities of transients in electrical circuits with massive conductors of pulsed power facilities","authors":"B. Fridman, R. Enikeev","doi":"10.1109/PPPS.2007.4652426","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4652426","url":null,"abstract":"At a small skin depth the electromagnetic field in conductors can be defined by the boundary layer method. The derived asymptotic solution makes it possible to determine the expansion in a series of the voltage drop across massive conductors. In this expansion the first term describes the limiting solution with infinite conductivity and corresponds to self-induction electro-motive force (EMF) of the external magnetic field or voltage drop across external inductance of massive conductors. Asymptotic correction of the first-order approximation corresponds to the fraction of the voltage drop calculated under the impedance boundary conditions on the surface of the conductors. The second-order correction takes into account the curvature of the conductor surface and inhomogeneity of the external magnetic field and varies in time directly as does current in the conductors, i.e. as in the case with voltage drop across a usual resistor. Such approximation establishes the relation between current and voltage drop on massive conductors, which can be included into the Kirchhoff’s equations for analysis and calculation of the transients in the circuits with massive conductors. The purpose of the paper is consideration of the peculiarities of the transients in electrical circuits, the methods of measurement of the massive conductor parameters, as well as the methods of the transients calculations in the time domain, which use the asymptotic representation of the voltage drop on massive conductors.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124637676","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4651816
W. Xie, Q. Sun, S. Hao, J. Deng, Z. Liu, W. Dai, W. Han
This paper describes the designs and experimental investigation of indirectly charged two stage helical explosive magnetic flux compression generator (MFCG), pulsed power conditioning system with explosive metal wire array opening switch and the combined experimental results of the two systems above. This MFCG can generate high current (115kA) on comparatively high inductance inductor (4.5μH). The length of current pulse (from zero to the biggest) on the inductor is about 10Ωs. Energy gain of the MFCG is greater than 30 times. Combined experiment of the two system shows that more than 25GW of high power pulse can be reached on 10Ω-load resistor, and width of the pulse is more than 150ns. The experiment shows that the systems of which we studied are very successful and practical in producing high power pulse for MFCG.
{"title":"Experimental investigation of explosive high power pulse source","authors":"W. Xie, Q. Sun, S. Hao, J. Deng, Z. Liu, W. Dai, W. Han","doi":"10.1109/PPPS.2007.4651816","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4651816","url":null,"abstract":"This paper describes the designs and experimental investigation of indirectly charged two stage helical explosive magnetic flux compression generator (MFCG), pulsed power conditioning system with explosive metal wire array opening switch and the combined experimental results of the two systems above. This MFCG can generate high current (115kA) on comparatively high inductance inductor (4.5μH). The length of current pulse (from zero to the biggest) on the inductor is about 10Ωs. Energy gain of the MFCG is greater than 30 times. Combined experiment of the two system shows that more than 25GW of high power pulse can be reached on 10Ω-load resistor, and width of the pulse is more than 150ns. The experiment shows that the systems of which we studied are very successful and practical in producing high power pulse for MFCG.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129715006","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4345664
Y. Yin, J.L. Liu, H. Zhong, J.H. Feng
This study uses a two-pulse method to determine the insulation recovery times of gas spark gap switch with different gas types applied in high power accelerator with water dielectric pulse forming line. Under the breakdown voltage of 450kV (the vacuum diode voltage is about 200kV), current 30kA, recovery characteristics of H2, N2, SF6 were studied. The recovery percentages of gas breakdown voltage and vacuum diode voltage were given. The results show that hydrogen has the best recovery characteristic. At a pulse interval of 8.8ms, recovery percentages of both gas breakdown voltage and vacuum diode voltage exceed 95%; for SF6, N2 with the interval of 25ms and 50ms, 90% voltage recovery percentages are obtained. The experiments also prove that the repetitive rate of high power accelerator with pulse forming line is mainly restricted by the gas switch repetitive rate; recovery percentages of the vacuum diode voltage and gas switch breakdown voltage are consistent; hydrogen switch can be employed for high repetitive rate high power accelerator with pulse forming line.
{"title":"Experimental study of the voltage recovery characteristics of spark gap switch with different gases","authors":"Y. Yin, J.L. Liu, H. Zhong, J.H. Feng","doi":"10.1109/PPPS.2007.4345664","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4345664","url":null,"abstract":"This study uses a two-pulse method to determine the insulation recovery times of gas spark gap switch with different gas types applied in high power accelerator with water dielectric pulse forming line. Under the breakdown voltage of 450kV (the vacuum diode voltage is about 200kV), current 30kA, recovery characteristics of H2, N2, SF6 were studied. The recovery percentages of gas breakdown voltage and vacuum diode voltage were given. The results show that hydrogen has the best recovery characteristic. At a pulse interval of 8.8ms, recovery percentages of both gas breakdown voltage and vacuum diode voltage exceed 95%; for SF6, N2 with the interval of 25ms and 50ms, 90% voltage recovery percentages are obtained. The experiments also prove that the repetitive rate of high power accelerator with pulse forming line is mainly restricted by the gas switch repetitive rate; recovery percentages of the vacuum diode voltage and gas switch breakdown voltage are consistent; hydrogen switch can be employed for high repetitive rate high power accelerator with pulse forming line.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129790802","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4346005
P. Kirawanich, S. Yakura, N. Islam
The effects of wideband high power pulses on the electrical components of an electrical have been studied through experiments and simulation. A numerical scheme based on the modular scattering junction concept that combines several EMT computational steps into a single EMT simulation is proposed. This scheme involves the simultaneous usage of a number of analytical and computational methods, including the transmission-line matrix compaction, the finite-difference time-domain, and reciprocity theorem. The method allows for sub-structural modifications without having to repeat calculations for the entire system. The numerical results generated by this proposed scheme have been validated through experimental results. The EMT-based calculations and the measured currents on the cable behind a slot aperture showed good agreement with each other, thus showing the accuracy of the proposed scheme. The proposed scheme is modular in nature and allows for the addition of more modules later in the simulation cycle without having to repeat the whole simulation calculation each time the network configuration changes slightly.
{"title":"A study of wideband pulse interactions on a large system using the modular junction topological approach","authors":"P. Kirawanich, S. Yakura, N. Islam","doi":"10.1109/PPPS.2007.4346005","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4346005","url":null,"abstract":"The effects of wideband high power pulses on the electrical components of an electrical have been studied through experiments and simulation. A numerical scheme based on the modular scattering junction concept that combines several EMT computational steps into a single EMT simulation is proposed. This scheme involves the simultaneous usage of a number of analytical and computational methods, including the transmission-line matrix compaction, the finite-difference time-domain, and reciprocity theorem. The method allows for sub-structural modifications without having to repeat calculations for the entire system. The numerical results generated by this proposed scheme have been validated through experimental results. The EMT-based calculations and the measured currents on the cable behind a slot aperture showed good agreement with each other, thus showing the accuracy of the proposed scheme. The proposed scheme is modular in nature and allows for the addition of more modules later in the simulation cycle without having to repeat the whole simulation calculation each time the network configuration changes slightly.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128975716","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4652437
S. Shkuratov, E. Talantsev, J. Baird, L. Altgilbers, A. Stults
A new concept for compact autonomous completely explosive pulsed power systems is presented. This concept utilizes the physical effect of transverse shock wave demagnetization of Nd2Fe14B high-energy hard ferromagnets and magnetic flux compression. This compact pulsed power system contains two stages. The first stage is a high-power transverse shock wave ferromagnetic generator (FMG) that serves as a primary power source (seed source). The second stage is a compact magnetic flux compression generator (FCG) that serves as a pulsed power amplifier. Experimental data are presented for operation of a compact completely explosive system based on the FMG seed source and a helical FCG.
{"title":"Compact autonomous completely explosive pulsed power system","authors":"S. Shkuratov, E. Talantsev, J. Baird, L. Altgilbers, A. Stults","doi":"10.1109/PPPS.2007.4652437","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4652437","url":null,"abstract":"A new concept for compact autonomous completely explosive pulsed power systems is presented. This concept utilizes the physical effect of transverse shock wave demagnetization of Nd2Fe14B high-energy hard ferromagnets and magnetic flux compression. This compact pulsed power system contains two stages. The first stage is a high-power transverse shock wave ferromagnetic generator (FMG) that serves as a primary power source (seed source). The second stage is a compact magnetic flux compression generator (FCG) that serves as a pulsed power amplifier. Experimental data are presented for operation of a compact completely explosive system based on the FMG seed source and a helical FCG.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129103356","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4345881
F. Rocchi, S. Mannucci, D. Mostacci, M. Sumini, A. Tartari, E. Angeli, R. Beverly
PFMA-1 is a 150 kJ, 40 nH Mather-type plasma focus designed for repetition frequencies up to 1 Hz and dedicated to the neutron-free endogenous production of 18F. PFMA-1 utilizes 32 capacitors, 11.1 μF each, charged in parallel at 30 kV. Snowplow calculations predict a 1.5 MA peak current and a 2.5 μs quarter-period for this device. To achieve low inductance and high peak current, one spark gap and four coaxial cables are employed per capacitor. Field-distortion, swing-cascade spark gaps were developed by R. E. Beverly III & Associates for this application (model SG-183). These switches mount directly onto the capacitor’s modified Scyllac-type bushing and are enclosed by a low-inductance grounded shield. The rated peak current is 160 kA, the maximum charge transferred is ≈ 0.4 C/shot, the self-inductance is 26 nH, and the breakdown jitter is ≈ 1 ns at 30 kV and 60 kPa dry air. The switches are cooled by a combination of deionized water, SF6 and dry air. The estimated electrode lifetime is ≈ 0.1 Mshots. Special B-dot probes within each switch canister monitor the discharge of every capacitor. Simultaneous triggering of all capacitors is accomplished by a 32-channel PFL generator. Some experimental results and waveforms obtained during preliminary testing of the facility are presented and compared with design values.
{"title":"PFMA-1: A 1-Hz, 150-kJ pulsed power system for plasma focus generation","authors":"F. Rocchi, S. Mannucci, D. Mostacci, M. Sumini, A. Tartari, E. Angeli, R. Beverly","doi":"10.1109/PPPS.2007.4345881","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4345881","url":null,"abstract":"PFMA-1 is a 150 kJ, 40 nH Mather-type plasma focus designed for repetition frequencies up to 1 Hz and dedicated to the neutron-free endogenous production of 18F. PFMA-1 utilizes 32 capacitors, 11.1 μF each, charged in parallel at 30 kV. Snowplow calculations predict a 1.5 MA peak current and a 2.5 μs quarter-period for this device. To achieve low inductance and high peak current, one spark gap and four coaxial cables are employed per capacitor. Field-distortion, swing-cascade spark gaps were developed by R. E. Beverly III & Associates for this application (model SG-183). These switches mount directly onto the capacitor’s modified Scyllac-type bushing and are enclosed by a low-inductance grounded shield. The rated peak current is 160 kA, the maximum charge transferred is ≈ 0.4 C/shot, the self-inductance is 26 nH, and the breakdown jitter is ≈ 1 ns at 30 kV and 60 kPa dry air. The switches are cooled by a combination of deionized water, SF6 and dry air. The estimated electrode lifetime is ≈ 0.1 Mshots. Special B-dot probes within each switch canister monitor the discharge of every capacitor. Simultaneous triggering of all capacitors is accomplished by a 32-channel PFL generator. Some experimental results and waveforms obtained during preliminary testing of the facility are presented and compared with design values.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132500168","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4345977
J. Barroso
An excitation model for TM-mode cylindrical cavities driven by a modulated electron beam with application in transit-time microwave tubes is developed. It is shown that the slowly time varying amplitude of the self-sustained oscillations is described by a reduced form of the classical van der Pol equation, from which expressions for the starting current and saturation amplitude are readily derived.
{"title":"Start up and saturation in monotrons","authors":"J. Barroso","doi":"10.1109/PPPS.2007.4345977","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4345977","url":null,"abstract":"An excitation model for TM-mode cylindrical cavities driven by a modulated electron beam with application in transit-time microwave tubes is developed. It is shown that the slowly time varying amplitude of the self-sustained oscillations is described by a reduced form of the classical van der Pol equation, from which expressions for the starting current and saturation amplitude are readily derived.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130274163","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 : 2007-06-17DOI: 10.1109/PPPS.2007.4346127
R. Mason, M. Wei, F. Beg, R. Stephens, C. Snell
The transport of relativistic electrons1 generated in wire and foil targets by short-pulse lasers is examined with the new e-PLAS simulation code based on implicit-moment/hybrid2 techniques. In a 50 μm diameter Cu wire (Zeff = 15) as recently illuminated on the TITAN LLNL laser, for example, a 1.7×1020 W/cm2 simulated laser beam delivering a flat 30 μm spot from the left (with 40 % absorption) generates the hot electron density profile depicted below at 940 fs. The peak hot density in the laser spot is ∼3×1021 electrons/cm3. This density drops to 3x1019 electrons/cm3 200 microns into the wire. A peak temperature of 2 keV is achieved through Joule heating of the background electrons in the wire “head” near the deposition surface; a significantly lower ∼0.4 keV is achieved in the wire body. Here, 300 MG thermoelectric B-fields are also calculated. Parameter studies relate the hot electron stopping to the surface B-field, modest drag slowing, and the background cold electron resisitvity, which is bleached by background heating to low values at late times.
{"title":"e-PLAS analysis of short pulse laser-matter interaction experiments","authors":"R. Mason, M. Wei, F. Beg, R. Stephens, C. Snell","doi":"10.1109/PPPS.2007.4346127","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4346127","url":null,"abstract":"The transport of relativistic electrons<sup>1</sup> generated in wire and foil targets by short-pulse lasers is examined with the new e-PLAS simulation code based on implicit-moment/hybrid<sup>2</sup> techniques. In a 50 μm diameter Cu wire (Z<inf>eff</inf> = 15) as recently illuminated on the TITAN LLNL laser, for example, a 1.7×10<sup>20</sup> W/cm<sup>2</sup> simulated laser beam delivering a flat 30 μm spot from the left (with 40 % absorption) generates the hot electron density profile depicted below at 940 fs. The peak hot density in the laser spot is ∼3×10<sup>21</sup> electrons/cm<sup>3</sup>. This density drops to 3x10<sup>19</sup> electrons/cm<sup>3</sup> 200 microns into the wire. A peak temperature of 2 keV is achieved through Joule heating of the background electrons in the wire “head” near the deposition surface; a significantly lower ∼0.4 keV is achieved in the wire body. Here, 300 MG thermoelectric B-fields are also calculated. Parameter studies relate the hot electron stopping to the surface B-field, modest drag slowing, and the background cold electron resisitvity, which is bleached by background heating to low values at late times.","PeriodicalId":275106,"journal":{"name":"2007 16th IEEE International Pulsed Power Conference","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127882295","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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