Pub Date : 2017-06-01DOI: 10.1109/PPC.2017.8291194
F. Punanov, R. Emlin, P. Morozov, S. Cholakh
In this work, we present the results of measurements of the electrical breakdown velocity in perfluorinated liquids of several chemical classes. Breakdown is initiated from point anode by 8-ns pulses with a rise time less than 0.5 ns at voltage of 140 kV. We show that perfluorinated esters have close values of breakdown velocity over a wide range of gaps, and demonstrate relatively low jitter in gaps for which time to breakdown is comparable to pulse duration.
{"title":"Multi-pulse nanosecond electrical breakdown in perfluorinated liquids at 140 kV","authors":"F. Punanov, R. Emlin, P. Morozov, S. Cholakh","doi":"10.1109/PPC.2017.8291194","DOIUrl":"https://doi.org/10.1109/PPC.2017.8291194","url":null,"abstract":"In this work, we present the results of measurements of the electrical breakdown velocity in perfluorinated liquids of several chemical classes. Breakdown is initiated from point anode by 8-ns pulses with a rise time less than 0.5 ns at voltage of 140 kV. We show that perfluorinated esters have close values of breakdown velocity over a wide range of gaps, and demonstrate relatively low jitter in gaps for which time to breakdown is comparable to pulse duration.","PeriodicalId":247019,"journal":{"name":"2017 IEEE 21st International Conference on Pulsed Power (PPC)","volume":"323 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133303267","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 : 2017-06-01DOI: 10.1109/PPC.2017.8291277
B. Hosseini, A. Guionet, H. Akiyama, H. Hosseini
Biofuel production as a sustainable source of green energy is considered as promising complements to petroleum in order to prevent environmental problems such as global warming. In this regard, microalgae can be one of the best options since other plant resources may be used for human consumption, using them for producing biofuel may cause an increase in their price. However, there are several challenges to extract oil from microalgae, e.g., high energy consumption, chemical solvents, and algae culture destruction; which should be addressed by new approaches. This study suggests nanosecond pulse electric fields (nsPEF) as a physical method for hydrocarbon extraction from microalgae. Botryococcus braunii with high hydrocarbon production potential was used as microalga model. For nanosecond pulsed electric fields (nsPEF) experiments, 20 to 65 kV/cm electric fields with 80 ns pulse duration, with different pulse repetition frequencies and pulse numbers were applied. Fluorescence microscopic observation and image and chemical assessments were performed for analyzing the samples, understanding the extraction mechanisms, and comparing the outcomes. According to the results, pulsed power approach can be used as high efficiency physical method for extracting oil from Botryococcus braunii.
{"title":"Study of oil extraction from microalgae by pulsed power as a renewable source of green energy","authors":"B. Hosseini, A. Guionet, H. Akiyama, H. Hosseini","doi":"10.1109/PPC.2017.8291277","DOIUrl":"https://doi.org/10.1109/PPC.2017.8291277","url":null,"abstract":"Biofuel production as a sustainable source of green energy is considered as promising complements to petroleum in order to prevent environmental problems such as global warming. In this regard, microalgae can be one of the best options since other plant resources may be used for human consumption, using them for producing biofuel may cause an increase in their price. However, there are several challenges to extract oil from microalgae, e.g., high energy consumption, chemical solvents, and algae culture destruction; which should be addressed by new approaches. This study suggests nanosecond pulse electric fields (nsPEF) as a physical method for hydrocarbon extraction from microalgae. Botryococcus braunii with high hydrocarbon production potential was used as microalga model. For nanosecond pulsed electric fields (nsPEF) experiments, 20 to 65 kV/cm electric fields with 80 ns pulse duration, with different pulse repetition frequencies and pulse numbers were applied. Fluorescence microscopic observation and image and chemical assessments were performed for analyzing the samples, understanding the extraction mechanisms, and comparing the outcomes. According to the results, pulsed power approach can be used as high efficiency physical method for extracting oil from Botryococcus braunii.","PeriodicalId":247019,"journal":{"name":"2017 IEEE 21st International Conference on Pulsed Power (PPC)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127199443","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 : 2017-06-01DOI: 10.1109/ppc.2017.8291250
J. Rodziewicz, E. Carlier, T. Fowler, B. Goddard, N. Magnin, O. Rabot
The LHC (Large Hadron Collider) beam extraction kicker system, composed of 15 fast kicker magnets per beam, is used to extract the particles in one turn from the collider and to dispose of them, after dilution, on an external absorber. Each of the 15 magnets is powered by a separate pulse generator, all of which are simultaneously triggered when a beam extraction from the machine is requested. Spontaneous firing of a single generator will create beam oscillations that are likely to exceed the accelerator aperture, resulting in beam losses and potential damage to the machine. In order to protect against occurrence of such events, a Re-Triggering System (RTS) has been implemented to redistribute, as fast as possible, a trigger request issued from the spontaneous-firing generator to all 15 generators. A prospect for a RTS based on passively generated and transmitted optical power to all others generators has been studied as an alternative to existing re-triggering line solution. This can be accomplished by coupling light from a number of diode laser arrays at re-trigger sources of one generator to bundles of optical fibres subsequently dispatched to all 15 generators. At each generator control stage we foresee a re-triggering switch which ensures the conversion of the light signal into an isolated electrical triggering pulse.
{"title":"Prospects for an optical re-triggering system for the LHC beam dumping system at CERN","authors":"J. Rodziewicz, E. Carlier, T. Fowler, B. Goddard, N. Magnin, O. Rabot","doi":"10.1109/ppc.2017.8291250","DOIUrl":"https://doi.org/10.1109/ppc.2017.8291250","url":null,"abstract":"The LHC (Large Hadron Collider) beam extraction kicker system, composed of 15 fast kicker magnets per beam, is used to extract the particles in one turn from the collider and to dispose of them, after dilution, on an external absorber. Each of the 15 magnets is powered by a separate pulse generator, all of which are simultaneously triggered when a beam extraction from the machine is requested. Spontaneous firing of a single generator will create beam oscillations that are likely to exceed the accelerator aperture, resulting in beam losses and potential damage to the machine. In order to protect against occurrence of such events, a Re-Triggering System (RTS) has been implemented to redistribute, as fast as possible, a trigger request issued from the spontaneous-firing generator to all 15 generators. A prospect for a RTS based on passively generated and transmitted optical power to all others generators has been studied as an alternative to existing re-triggering line solution. This can be accomplished by coupling light from a number of diode laser arrays at re-trigger sources of one generator to bundles of optical fibres subsequently dispatched to all 15 generators. At each generator control stage we foresee a re-triggering switch which ensures the conversion of the light signal into an isolated electrical triggering pulse.","PeriodicalId":247019,"journal":{"name":"2017 IEEE 21st International Conference on Pulsed Power (PPC)","volume":"69 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133790559","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 : 2017-06-01DOI: 10.1109/PPC.2017.8291318
Seiya Komatsudaira, Ryoma Ogata, Katsuyuki Takahashi, M. Akiyama, K. Takaki
Pulsed power generators have been used in various fields such as environment, biology, agriculture and so on. Therefore, many researchers demand functions such as high power, short pulse, safety, miniaturization, low cost and ease of use. Our research aimed to develop a high performance pulsed power generator. The generator has ease of use and miniaturization. It is able to output various trigger signals by a PC. Even if without PC, it can output trigger signals of about 10 patterns. The generator consists of a capacitor discharge circuit, a controller and a high voltage DC power supply. IGBTs (Model number: IXGX32N170H1 of IXYS) are used for the switching element of the capacitor discharge circuit. The controller consists of a Field Programmable Gate Array (FPGA) and an Arduino. The FPGA (Model number: Spartan-3AN of Xilinx) is used for the control the trigger signal of IGBTs, and the Arduino is used for the communication with a PC and display on a monitor. As results, the maximum output voltage was about 1.7 kV without pulse transformer. In addition, the maximum output voltage with pulse transformer was about 10 kV. The ease of use will be important for industry applications of the pulsed power field.
{"title":"Development of high performance pulsed power generator using FPGA and Arduino","authors":"Seiya Komatsudaira, Ryoma Ogata, Katsuyuki Takahashi, M. Akiyama, K. Takaki","doi":"10.1109/PPC.2017.8291318","DOIUrl":"https://doi.org/10.1109/PPC.2017.8291318","url":null,"abstract":"Pulsed power generators have been used in various fields such as environment, biology, agriculture and so on. Therefore, many researchers demand functions such as high power, short pulse, safety, miniaturization, low cost and ease of use. Our research aimed to develop a high performance pulsed power generator. The generator has ease of use and miniaturization. It is able to output various trigger signals by a PC. Even if without PC, it can output trigger signals of about 10 patterns. The generator consists of a capacitor discharge circuit, a controller and a high voltage DC power supply. IGBTs (Model number: IXGX32N170H1 of IXYS) are used for the switching element of the capacitor discharge circuit. The controller consists of a Field Programmable Gate Array (FPGA) and an Arduino. The FPGA (Model number: Spartan-3AN of Xilinx) is used for the control the trigger signal of IGBTs, and the Arduino is used for the communication with a PC and display on a monitor. As results, the maximum output voltage was about 1.7 kV without pulse transformer. In addition, the maximum output voltage with pulse transformer was about 10 kV. The ease of use will be important for industry applications of the pulsed power field.","PeriodicalId":247019,"journal":{"name":"2017 IEEE 21st International Conference on Pulsed Power (PPC)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114477188","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 : 2017-06-01DOI: 10.1109/PPC.2017.8291235
R. W. Macpherson, M. Wilson, S. Macgregor, I. Timoshkin, M. Given, T. Wang
This paper informs on the characterisation of a corona-stabilised switch in environmentally-friendly alternative gases to SF6. A DC high voltage is applied to an electrode with a sharp edge within the sealed switching system, upon which, the non-uniform electrical field establishes a corona discharge, creating an ionization region. The electrical field strength at this region is low enough that breakdown will not occur, until triggered by an impulsive trigger voltage. It is common that SF6 (Sulphur hexafluoride) is used within these switches, although, due to its high global warming potential, other gases are being tested in order to find suitable, environmentally-friendly, alternatives. The gas tested was the refrigerant 1,3,3,3-tetrafluoropropene, also known as HFO-1234ze, in mixtures with nitrogen (N2). Characterisation of the triggering range, delay times and jitter in the single-shot regime reveals that, with the use of HFO-1234ze, the breakdown voltage can be increased to ~280%, ~290% and ~306% of that using N2 alone, over the pressure range 0–3 bar gauge; these results were achieved with 5%, 10% and 20% of HFO-1234ze by pressure, respectively. The calculated jitter was found to vary between 0–3.3 μs with 100% N2 (at 98% self-breakdown voltage); 0.2–6.4 μs for 5% HFO-1234ze; 1.7–5.9 μs for 10% HFO-1234ze; and 1.8–3.2 μs for 20% HFO-1234ze (all taken at 75% self-breakdown voltage). The maximum triggering range in N2 was 1 kV, compared to a maximum of 10 kV with 5% HFO-1234ze; 13.6 kV with 10% HFO-1234ze; and 12.2 kV with 20% HFO-1234ze.
{"title":"Characterisation of a corona-stabilised switch in alternative gas mixtures","authors":"R. W. Macpherson, M. Wilson, S. Macgregor, I. Timoshkin, M. Given, T. Wang","doi":"10.1109/PPC.2017.8291235","DOIUrl":"https://doi.org/10.1109/PPC.2017.8291235","url":null,"abstract":"This paper informs on the characterisation of a corona-stabilised switch in environmentally-friendly alternative gases to SF6. A DC high voltage is applied to an electrode with a sharp edge within the sealed switching system, upon which, the non-uniform electrical field establishes a corona discharge, creating an ionization region. The electrical field strength at this region is low enough that breakdown will not occur, until triggered by an impulsive trigger voltage. It is common that SF6 (Sulphur hexafluoride) is used within these switches, although, due to its high global warming potential, other gases are being tested in order to find suitable, environmentally-friendly, alternatives. The gas tested was the refrigerant 1,3,3,3-tetrafluoropropene, also known as HFO-1234ze, in mixtures with nitrogen (N2). Characterisation of the triggering range, delay times and jitter in the single-shot regime reveals that, with the use of HFO-1234ze, the breakdown voltage can be increased to ~280%, ~290% and ~306% of that using N2 alone, over the pressure range 0–3 bar gauge; these results were achieved with 5%, 10% and 20% of HFO-1234ze by pressure, respectively. The calculated jitter was found to vary between 0–3.3 μs with 100% N2 (at 98% self-breakdown voltage); 0.2–6.4 μs for 5% HFO-1234ze; 1.7–5.9 μs for 10% HFO-1234ze; and 1.8–3.2 μs for 20% HFO-1234ze (all taken at 75% self-breakdown voltage). The maximum triggering range in N2 was 1 kV, compared to a maximum of 10 kV with 5% HFO-1234ze; 13.6 kV with 10% HFO-1234ze; and 12.2 kV with 20% HFO-1234ze.","PeriodicalId":247019,"journal":{"name":"2017 IEEE 21st International Conference on Pulsed Power (PPC)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114762890","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 : 2017-06-01DOI: 10.1109/PPC.2017.8291229
Ya. O. Hrechko, N. Azarenkov, A. Tseluyko, Ie. V. Babenko, D. Ryabchikov, I. Sereda, A. Kashirin
The work deals with obtaining a high pulsed power in the high-current plasma diode. It has been shown that under certain conditions in the plasma diode, a space charge double electric layer is formed in the current-carrying plasma. Almost all active discharge voltage focuses on it. In this case the pulse and local energy input into the plasma occurs. The possibility of obtaining the pulsed power inputted into the discharge over 100 MW at relatively small stored energy in capacitor bank (up to 200 J) under conditions of the double layer formation has been shown in this paper. This allows using such plasma diode for generating the powerful directional extreme ultraviolet radiation. The observed radiation power at a wavelength of 13.5 nm reached up to 3 MW. The relation between the radiation directivity and the mechanism of the double layer formation in even and odd half-periods of the discharge current oscillation has been noted in this paper.
{"title":"The efficiency of the pulsed power input in the limited plasma diode","authors":"Ya. O. Hrechko, N. Azarenkov, A. Tseluyko, Ie. V. Babenko, D. Ryabchikov, I. Sereda, A. Kashirin","doi":"10.1109/PPC.2017.8291229","DOIUrl":"https://doi.org/10.1109/PPC.2017.8291229","url":null,"abstract":"The work deals with obtaining a high pulsed power in the high-current plasma diode. It has been shown that under certain conditions in the plasma diode, a space charge double electric layer is formed in the current-carrying plasma. Almost all active discharge voltage focuses on it. In this case the pulse and local energy input into the plasma occurs. The possibility of obtaining the pulsed power inputted into the discharge over 100 MW at relatively small stored energy in capacitor bank (up to 200 J) under conditions of the double layer formation has been shown in this paper. This allows using such plasma diode for generating the powerful directional extreme ultraviolet radiation. The observed radiation power at a wavelength of 13.5 nm reached up to 3 MW. The relation between the radiation directivity and the mechanism of the double layer formation in even and odd half-periods of the discharge current oscillation has been noted in this paper.","PeriodicalId":247019,"journal":{"name":"2017 IEEE 21st International Conference on Pulsed Power (PPC)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122014925","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 : 2017-06-01DOI: 10.1109/PPC.2017.8291222
Jun Zhou, H. Ding, Yening Liu, Zhangfei Zhao, Yongheng Huang, X. Fang, Qingjian Wang
High pulsed magnetic field, particle accelerator, strong laser, electromagnetic emission and other pulsed power systems require energy provided by fast charging capacitor with short duration and high density. It is necessary to recharge the capacitor to specific voltage by charging power supply after the discharge of energy stored in the capacitor. Charging power supply applied in high power capacitive pulsed system has the characteristics of high voltage, large charging current and high efficiency, and such characteristics provide opportunities and challenges to its research and development. At Wuhan National Magnetic Field Center, a scheme of high power charging power supply applied in capacitive pulsed power system for high pulsed magnetic field is proposed with parameters of 15 kV rated voltage, 770 A maximum current and 8.3 MW peak power. Multiple BUCK circuit topology is employed to reduce charging current ripple and each BUCK circuit operates reliably in discontinuous continuous current mode to eliminate the overvoltage caused by reverse recovery of freewheeling diode. Simulation model of the designed charging power supply is established that simulation result shows the validity and feasibility of the scheme.
{"title":"A high power charging power supply for capacitor in pulsed power system","authors":"Jun Zhou, H. Ding, Yening Liu, Zhangfei Zhao, Yongheng Huang, X. Fang, Qingjian Wang","doi":"10.1109/PPC.2017.8291222","DOIUrl":"https://doi.org/10.1109/PPC.2017.8291222","url":null,"abstract":"High pulsed magnetic field, particle accelerator, strong laser, electromagnetic emission and other pulsed power systems require energy provided by fast charging capacitor with short duration and high density. It is necessary to recharge the capacitor to specific voltage by charging power supply after the discharge of energy stored in the capacitor. Charging power supply applied in high power capacitive pulsed system has the characteristics of high voltage, large charging current and high efficiency, and such characteristics provide opportunities and challenges to its research and development. At Wuhan National Magnetic Field Center, a scheme of high power charging power supply applied in capacitive pulsed power system for high pulsed magnetic field is proposed with parameters of 15 kV rated voltage, 770 A maximum current and 8.3 MW peak power. Multiple BUCK circuit topology is employed to reduce charging current ripple and each BUCK circuit operates reliably in discontinuous continuous current mode to eliminate the overvoltage caused by reverse recovery of freewheeling diode. Simulation model of the designed charging power supply is established that simulation result shows the validity and feasibility of the scheme.","PeriodicalId":247019,"journal":{"name":"2017 IEEE 21st International Conference on Pulsed Power (PPC)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129900417","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 : 2017-06-01DOI: 10.1109/PPC.2017.8291300
D. Ikoma, D. Wang, T. Namihira
Dielectric Barrier Discharge type ozonizers has been used in water treatment, sterilization, and deodorization for many years. However, the yield in ozone generation leaves a room to expand its utilization. On the other hand, maximum ozone concentration remains lower value than that required for further industrial applications [1]. A main cause of ozone concentration saturation is assumed to be gas temperature rise near the H.V. central electrode of the coaxial cylindrical electrodes. This paper describes the effects of center electrode cooling on ozone concentration. In this study, a tube-cylinder reactor was used. The center electrode, with an inner diameter of 6 mm and outer diameter of 8 mm, allowed coolant to flow inside of it. Results show the possibility of high voltage application by increasing the diameter of the center electrode and suppressing gas temperature rise in the vicinity of the center electrode. Furthermore, higher ozone concentrations could be produced compared with conventional wire-cylinder reactors. These results suggest that suppression of gas temperature rise near the center electrode is efficient for suppressing ozone decomposition in ozone production using nanosecond pulsed discharge.
{"title":"Nanosecond pulsed discharge type ozonizer with cooling structure","authors":"D. Ikoma, D. Wang, T. Namihira","doi":"10.1109/PPC.2017.8291300","DOIUrl":"https://doi.org/10.1109/PPC.2017.8291300","url":null,"abstract":"Dielectric Barrier Discharge type ozonizers has been used in water treatment, sterilization, and deodorization for many years. However, the yield in ozone generation leaves a room to expand its utilization. On the other hand, maximum ozone concentration remains lower value than that required for further industrial applications [1]. A main cause of ozone concentration saturation is assumed to be gas temperature rise near the H.V. central electrode of the coaxial cylindrical electrodes. This paper describes the effects of center electrode cooling on ozone concentration. In this study, a tube-cylinder reactor was used. The center electrode, with an inner diameter of 6 mm and outer diameter of 8 mm, allowed coolant to flow inside of it. Results show the possibility of high voltage application by increasing the diameter of the center electrode and suppressing gas temperature rise in the vicinity of the center electrode. Furthermore, higher ozone concentrations could be produced compared with conventional wire-cylinder reactors. These results suggest that suppression of gas temperature rise near the center electrode is efficient for suppressing ozone decomposition in ozone production using nanosecond pulsed discharge.","PeriodicalId":247019,"journal":{"name":"2017 IEEE 21st International Conference on Pulsed Power (PPC)","volume":"3 9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127465760","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 : 2017-06-01DOI: 10.1109/PPC.2017.8291200
P. Gourdain, M. Adams
MagLIF is a promising inertial fusion based platform studied on the Z machine, at Sandia National Laboratories. This fusion scheme combines z-pinch liner implosion, laser heating and magnetic field confinement. A wealth of physical processes can be studied using this platform, from electron heat conduction to magnetic field compression, from magnetic Rayleigh-Taylor instabilities to particle confinement. Critical plasma parameters of the MagLIF concept are dimensionless. This suggests that most of the physics can be studied using university-scale pulsed-power drivers. However other parameters do not scale. One of them is the electrical resistivity, that is much larger on smaller devices. So, one can expect magnetic field compression on mega-ampere-class pulsed-power drivers to be much less effective. This work uses numerical simulations to demonstrate that if the return current posts surrounding the liner are tilted, a time-varying axial magnetic field is generated by the pulsed power driver. This field can diffuse inward, across the liner wall at the same speed that the initial axial field diffuses out. By picking the right angle for the posts, the inward and outward diffusions of both axial fields completely balance out, allowing to reach much more relevant dimensionless parameters. In fact, the rate of injection of the outer axial field can be much faster than the rate at which the inner axial field escapes, increasing the total field inside the liner even when no compression takes place. The injected axial field distribution is also much different from the initial compressed field.
{"title":"Axial magnetic field injection on scaled-down maglif platforms","authors":"P. Gourdain, M. Adams","doi":"10.1109/PPC.2017.8291200","DOIUrl":"https://doi.org/10.1109/PPC.2017.8291200","url":null,"abstract":"MagLIF is a promising inertial fusion based platform studied on the Z machine, at Sandia National Laboratories. This fusion scheme combines z-pinch liner implosion, laser heating and magnetic field confinement. A wealth of physical processes can be studied using this platform, from electron heat conduction to magnetic field compression, from magnetic Rayleigh-Taylor instabilities to particle confinement. Critical plasma parameters of the MagLIF concept are dimensionless. This suggests that most of the physics can be studied using university-scale pulsed-power drivers. However other parameters do not scale. One of them is the electrical resistivity, that is much larger on smaller devices. So, one can expect magnetic field compression on mega-ampere-class pulsed-power drivers to be much less effective. This work uses numerical simulations to demonstrate that if the return current posts surrounding the liner are tilted, a time-varying axial magnetic field is generated by the pulsed power driver. This field can diffuse inward, across the liner wall at the same speed that the initial axial field diffuses out. By picking the right angle for the posts, the inward and outward diffusions of both axial fields completely balance out, allowing to reach much more relevant dimensionless parameters. In fact, the rate of injection of the outer axial field can be much faster than the rate at which the inner axial field escapes, increasing the total field inside the liner even when no compression takes place. The injected axial field distribution is also much different from the initial compressed field.","PeriodicalId":247019,"journal":{"name":"2017 IEEE 21st International Conference on Pulsed Power (PPC)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127512208","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 : 2017-06-01DOI: 10.1109/PPC.2017.8291191
S. Lacouture, J. Schrock, E. Hirsch, S. Bayne, H. O’Brien, A. Ogunniyi
To continually increase the voltage and current capabilities of power semiconductor devices, whether pushing older materials such as Si to its' intrinsic electrical limits or by employing newer substances like SiC or GaN, a thorough understanding of the entire device is required, from the basic physics of the material and its interactions with defects and passivation, up to the complete device structure, including terminal performance and device — level limitations. Of the fundamental parameters that affect device performance, the most complex and malleable is the carrier lifetime. Carrier lifetime has a profound effect on power devices designed for high voltage applications and power devices relying on conductivity modulation. This parameter cannot be given as a ball — park figure unlike mobility (and hence diffusion coefficients) as it is affected by nearly every processing step a device undergoes: a final device can have carrier lifetimes that differ drastically from the starting bulk material. The work herein utilizes a relatively new set of techniques collectively known as Lifetime Spectroscopy (LS) methods to extract fundamental material parameters relating to recombination activity: τη0, τρ0 and AEt. These LS methods directly measure recombination activity of defects and hence acquire characteristic data of defects and dopants that is complimentary in nature to the information gleaned about them from more orthodox methods such as Deep — Level Transient Spectroscopy (DLTS). The Open Circuit Voltage Decay (OCVD) method is used along with improved data manipulation algorithms to extract the effective carrier lifetime as injection and temperature are swept. A complete stand — alone system has been constructed that allows a very wide range of current injection (∼1mA to > 200A) and built — in OCVD waveform acquisition. The first complete Temperature — Injection Dependent Lifetime Spectroscopy (T-IDLS) studies are carried out on a small signal PiN commercial diode.
{"title":"Wide injection range OCVD system for lifetime spectroscopy techniques","authors":"S. Lacouture, J. Schrock, E. Hirsch, S. Bayne, H. O’Brien, A. Ogunniyi","doi":"10.1109/PPC.2017.8291191","DOIUrl":"https://doi.org/10.1109/PPC.2017.8291191","url":null,"abstract":"To continually increase the voltage and current capabilities of power semiconductor devices, whether pushing older materials such as Si to its' intrinsic electrical limits or by employing newer substances like SiC or GaN, a thorough understanding of the entire device is required, from the basic physics of the material and its interactions with defects and passivation, up to the complete device structure, including terminal performance and device — level limitations. Of the fundamental parameters that affect device performance, the most complex and malleable is the carrier lifetime. Carrier lifetime has a profound effect on power devices designed for high voltage applications and power devices relying on conductivity modulation. This parameter cannot be given as a ball — park figure unlike mobility (and hence diffusion coefficients) as it is affected by nearly every processing step a device undergoes: a final device can have carrier lifetimes that differ drastically from the starting bulk material. The work herein utilizes a relatively new set of techniques collectively known as Lifetime Spectroscopy (LS) methods to extract fundamental material parameters relating to recombination activity: τη0, τρ0 and AEt. These LS methods directly measure recombination activity of defects and hence acquire characteristic data of defects and dopants that is complimentary in nature to the information gleaned about them from more orthodox methods such as Deep — Level Transient Spectroscopy (DLTS). The Open Circuit Voltage Decay (OCVD) method is used along with improved data manipulation algorithms to extract the effective carrier lifetime as injection and temperature are swept. A complete stand — alone system has been constructed that allows a very wide range of current injection (∼1mA to > 200A) and built — in OCVD waveform acquisition. The first complete Temperature — Injection Dependent Lifetime Spectroscopy (T-IDLS) studies are carried out on a small signal PiN commercial diode.","PeriodicalId":247019,"journal":{"name":"2017 IEEE 21st International Conference on Pulsed Power (PPC)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129925480","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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