Pub Date : 2006-11-01DOI: 10.1109/MEGAGUSS.2006.4530714
C. Rousculp, J. Hammerberg, D. Oró, G. Rodriguez, P. Goodwin, M. Salazar, R. Reinovsky, R. Faehl, J. Becker, R. A. Berglin, K. W. Delzer, G. Gomez, R. Malone, D. Morgan, T. Pate, K. E. Theuer
A Series of dynamic friction experiments has been conducted at the Atlas Pulsed Power Facility. Pulsed currents in excess of 21 MAmps were delivered to a cylindrical liner in about 15 ¿s. The liner was accelerated to km/s velocities and symmetrically impacted a hollow Ta/Al/Ta target. Due to the shock speed difference in Ta and Al, sliding velocities of almost a km/s were achieved at the Ta/Al interfaces. Initial analysis indicates that the machine performed to within a few percent of the design specifications. The primary diagnostic for these experiments was three radiographic lines-of-sight to look at thin gold wires embedded within the Al piece of the target. The magnitude of the displacement and the amount of distortion of the wires near the material interface is used as a measure of the dynamic frictional forces occurring there. Other diagnostics included a single-point VISAR and line-ORVIS to measure the breakout time and velocity on the inside of the target. Also, the Faraday rotation of a laser beam through a circular loop of optical fiber located in the power-flow channel of the experiment is used to measure the total current delivered to the experimental load. Data are being compared to a theoretical dynamic friction model for high sliding velocities. The model is based on molecular dynamics simulations and predicts an inverse power law dependence of frictional forces at very high sliding velocities.
{"title":"Dynamic Friction Experiments at the Atlas Pulsed Power Facility","authors":"C. Rousculp, J. Hammerberg, D. Oró, G. Rodriguez, P. Goodwin, M. Salazar, R. Reinovsky, R. Faehl, J. Becker, R. A. Berglin, K. W. Delzer, G. Gomez, R. Malone, D. Morgan, T. Pate, K. E. Theuer","doi":"10.1109/MEGAGUSS.2006.4530714","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530714","url":null,"abstract":"A Series of dynamic friction experiments has been conducted at the Atlas Pulsed Power Facility. Pulsed currents in excess of 21 MAmps were delivered to a cylindrical liner in about 15 ¿s. The liner was accelerated to km/s velocities and symmetrically impacted a hollow Ta/Al/Ta target. Due to the shock speed difference in Ta and Al, sliding velocities of almost a km/s were achieved at the Ta/Al interfaces. Initial analysis indicates that the machine performed to within a few percent of the design specifications. The primary diagnostic for these experiments was three radiographic lines-of-sight to look at thin gold wires embedded within the Al piece of the target. The magnitude of the displacement and the amount of distortion of the wires near the material interface is used as a measure of the dynamic frictional forces occurring there. Other diagnostics included a single-point VISAR and line-ORVIS to measure the breakout time and velocity on the inside of the target. Also, the Faraday rotation of a laser beam through a circular loop of optical fiber located in the power-flow channel of the experiment is used to measure the total current delivered to the experimental load. Data are being compared to a theoretical dynamic friction model for high sliding velocities. The model is based on molecular dynamics simulations and predicts an inverse power law dependence of frictional forces at very high sliding velocities.","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":"131115110","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.2006.4530700
P. Duday, A. M. Glybin, B.T. Egorichev, V. A. Ivanov, A. I. Krayev, V. B. Kudel’kin, S. M. Polyushko, I. V. Morozov, S. V. Pak, A. N. Skobelev, G. I. Volkov
The facilities for pulsed compression of materials are necessary to study the phase transformations and the dynamic parameters of substances. The acceleration of the solid liners with the help of magnetic field of the explosive magnetic generator (EMG) with subsequent deceleration on a specimen allows carrying out the pulsed compression. The paper describes a powerful pulsed source of current on the basis of helical EMG Oslash240 mm and explosive current opening switch Oslash 300 mm that makes it possible to shape the current pulse with the amplitude 15 MA with rise time adjustable from 3 mus to 10 mus in the liner load.
{"title":"Powerful Pulsed Source with Adjustable Time of Current Rise on the Basis of Helical EMG and Explosive Opening Switch to Drive Solid Liners","authors":"P. Duday, A. M. Glybin, B.T. Egorichev, V. A. Ivanov, A. I. Krayev, V. B. Kudel’kin, S. M. Polyushko, I. V. Morozov, S. V. Pak, A. N. Skobelev, G. I. Volkov","doi":"10.1109/MEGAGUSS.2006.4530700","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530700","url":null,"abstract":"The facilities for pulsed compression of materials are necessary to study the phase transformations and the dynamic parameters of substances. The acceleration of the solid liners with the help of magnetic field of the explosive magnetic generator (EMG) with subsequent deceleration on a specimen allows carrying out the pulsed compression. The paper describes a powerful pulsed source of current on the basis of helical EMG Oslash240 mm and explosive current opening switch Oslash 300 mm that makes it possible to shape the current pulse with the amplitude 15 MA with rise time adjustable from 3 mus to 10 mus in the liner load.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"117 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":"133892135","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.2006.4530687
J. Parker, T. Cavazos, C. Roth, J. Degnan, G. Kiuttu, F. Lehr
The performance of a high-gain FCG is often limited by internal electrical breakdown caused by the high voltage generated during operation. Modern diagnostic techniques provide the opportunity to diagnose internal breakdowns so that generator designs can be improved. This paper describes the internal breakdowns observed in the JAKE FCG developed at the AFRL during the late 1990's. A revision to the stator winding pattern of the JAKE generator has led to improved control of the internal voltage. Designated JILL, the revised generator has substantially better flux transport efficiency, particularly at higher seed current. The techniques employed to design the new stator winding and the results of development testing are presented.
{"title":"Development and Testing of a High-Gain Magnetic Flux Compression Generator","authors":"J. Parker, T. Cavazos, C. Roth, J. Degnan, G. Kiuttu, F. Lehr","doi":"10.1109/MEGAGUSS.2006.4530687","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530687","url":null,"abstract":"The performance of a high-gain FCG is often limited by internal electrical breakdown caused by the high voltage generated during operation. Modern diagnostic techniques provide the opportunity to diagnose internal breakdowns so that generator designs can be improved. This paper describes the internal breakdowns observed in the JAKE FCG developed at the AFRL during the late 1990's. A revision to the stator winding pattern of the JAKE generator has led to improved control of the internal voltage. Designated JILL, the revised generator has substantially better flux transport efficiency, particularly at higher seed current. The techniques employed to design the new stator winding and the results of development testing are presented.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"87 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":"133045847","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.2006.4530689
T. Holt, A. Young, A. Neuber, M. Kristiansen
Performance reproducibility is a necessity when considering sources for single-shot, high-voltage applications. Helical flux compression generators (HFCGs) are attractive for a variety of single-shot applications and are capable of high energy amplification that can be used in conjunction with other pulse-shaping techniques such as an exploding wire fuse for achieving high output voltages [1,2]. Small scale HFCGs (with active volumes on the order of ~100-200 cm3), however, are known to perform unreliably from shot to shot [3] and can lose as much as 80% of the flux available in the system based on previous experience with small to mid-sized HFCGs [4]. The performance variation is often attributed to erratic armature expansion behavior and/or fabrication methods and tolerances [3, 4]. As the compressible volume increases, HFCGs are known to conserve more flux and perform more reliably [2]. A fabrication method is presented for a midsized (with active volumes on the order of ~300-400 cm3) dual-stage HFCG that aims to improve the reproducibility in shot to shot performance with the goal of increasing the appeal for use of HFCGs in single-shot pulsed-power applications. Results of experiments with inductive loads of ~3 muH are discussed.
{"title":"A Fabrication Method for a Mid-Sized, High-Energy-Density, Flux Compression Generator","authors":"T. Holt, A. Young, A. Neuber, M. Kristiansen","doi":"10.1109/MEGAGUSS.2006.4530689","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530689","url":null,"abstract":"Performance reproducibility is a necessity when considering sources for single-shot, high-voltage applications. Helical flux compression generators (HFCGs) are attractive for a variety of single-shot applications and are capable of high energy amplification that can be used in conjunction with other pulse-shaping techniques such as an exploding wire fuse for achieving high output voltages [1,2]. Small scale HFCGs (with active volumes on the order of ~100-200 cm3), however, are known to perform unreliably from shot to shot [3] and can lose as much as 80% of the flux available in the system based on previous experience with small to mid-sized HFCGs [4]. The performance variation is often attributed to erratic armature expansion behavior and/or fabrication methods and tolerances [3, 4]. As the compressible volume increases, HFCGs are known to conserve more flux and perform more reliably [2]. A fabrication method is presented for a midsized (with active volumes on the order of ~300-400 cm3) dual-stage HFCG that aims to improve the reproducibility in shot to shot performance with the goal of increasing the appeal for use of HFCGs in single-shot pulsed-power applications. Results of experiments with inductive loads of ~3 muH are discussed.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"18 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":"114204886","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.2006.4530680
C. Swenson, J. Sims, D. Rickel
The first phase of the US-DOE 100 T multi-shot pulsed magnet program has now been completed. The initial program goals were a non-destructive millisecond-scale 90 T pulse magnet system to support scientific research in high magnetic fields. Two magnet subsystems comprise the magnet: a nested array of seven generator-driven coils that produce 41.6 T in a 225 mm bore; and a capacitor-driven 15 mm bore "insert" magnet that produces 50.9 T inside the outer coil set. The US-DOE 100 T Multi-shot (MS) Pulsed Magnet Program is collaboration between US-DOE engineering teams at Los Alamos National Laboratory and the US-NSF engineering team at the National High Magnetic Field Laboratory located in Tallahassee Florida. The US-DOE is responsible for the systems integration and the development of the generator driven outer coil set. The US-NSF is responsible for the development and production of the capacitor driven insert magnet. The 90 T MS system is now in the commissioning phase of operations. This paper presents a review of the magnet design, operational performance data, and the developments required for the 50.9 T insert magnet. Technology for the 90 T insert evolved from a series of prototype magnets build to access engineering concepts and materials, and gain experience operating insert-like coils at the same temperature, stress, and strain regime as will ultimately be encountered at 100 T. We will access the performance of the 90 T insert in the context of the prototype development program and the requirements for future 100 T operations on the millisecond time scale.
{"title":"Performance of First 90 T Insert Magnet for US-DOE 100 T Multi-Shot Pulsed Magnet Program","authors":"C. Swenson, J. Sims, D. Rickel","doi":"10.1109/MEGAGUSS.2006.4530680","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530680","url":null,"abstract":"The first phase of the US-DOE 100 T multi-shot pulsed magnet program has now been completed. The initial program goals were a non-destructive millisecond-scale 90 T pulse magnet system to support scientific research in high magnetic fields. Two magnet subsystems comprise the magnet: a nested array of seven generator-driven coils that produce 41.6 T in a 225 mm bore; and a capacitor-driven 15 mm bore \"insert\" magnet that produces 50.9 T inside the outer coil set. The US-DOE 100 T Multi-shot (MS) Pulsed Magnet Program is collaboration between US-DOE engineering teams at Los Alamos National Laboratory and the US-NSF engineering team at the National High Magnetic Field Laboratory located in Tallahassee Florida. The US-DOE is responsible for the systems integration and the development of the generator driven outer coil set. The US-NSF is responsible for the development and production of the capacitor driven insert magnet. The 90 T MS system is now in the commissioning phase of operations. This paper presents a review of the magnet design, operational performance data, and the developments required for the 50.9 T insert magnet. Technology for the 90 T insert evolved from a series of prototype magnets build to access engineering concepts and materials, and gain experience operating insert-like coils at the same temperature, stress, and strain regime as will ultimately be encountered at 100 T. We will access the performance of the 90 T insert in the context of the prototype development program and the requirements for future 100 T operations on the millisecond time scale.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"21 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":"116142722","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.2006.4530715
A. Kaul, G. Rodriguez
The ability of pulsed-power to magnetically accelerate and drive high-precision liner-target implosions facilitates studies of material properties such as damage in cylindrically convergent geometry. Spallation damage experiments are usually conducted in a planar geometry, allowing for one-dimensional analysis of evolution of failure characteristics. Cylindrical experiments allow for a careful analysis of the effect of convergence and two-dimensional strains and shear stresses on the spallation profile of a material. This paper reports on a series of recent experiments to provide data describing the onset of failure of a well-characterized material (aluminum) in a cylindrically convergent geometry. Experimental data includes post-shot collection of the damaged target for subsequent metallographic analysis, dynamic VISAR velocimetry to infer the target material spallation strength and damage model parameters, and transverse radial radiography to assess drive and impact symmetry. This data is used to develop and validate damage and failure models. The theoretical basis, designs and results are presented for these experiments using explosively-driven pulsed power facilities.
{"title":"Spall and Damage in Convergent Geometry Using Pulsed Power","authors":"A. Kaul, G. Rodriguez","doi":"10.1109/MEGAGUSS.2006.4530715","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530715","url":null,"abstract":"The ability of pulsed-power to magnetically accelerate and drive high-precision liner-target implosions facilitates studies of material properties such as damage in cylindrically convergent geometry. Spallation damage experiments are usually conducted in a planar geometry, allowing for one-dimensional analysis of evolution of failure characteristics. Cylindrical experiments allow for a careful analysis of the effect of convergence and two-dimensional strains and shear stresses on the spallation profile of a material. This paper reports on a series of recent experiments to provide data describing the onset of failure of a well-characterized material (aluminum) in a cylindrically convergent geometry. Experimental data includes post-shot collection of the damaged target for subsequent metallographic analysis, dynamic VISAR velocimetry to infer the target material spallation strength and damage model parameters, and transverse radial radiography to assess drive and impact symmetry. This data is used to develop and validate damage and failure models. The theoretical basis, designs and results are presented for these experiments using explosively-driven pulsed power facilities.","PeriodicalId":338246,"journal":{"name":"2006 IEEE International Conference on Megagauss Magnetic Field Generation and Related Topics","volume":"47 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":"122443497","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.2006.4530684
Cheng Wang, X. Duan, K. Yu, T. Peng, Z. Xia, H. Ding, L. Li, F. Herlach, J. Vanacken
A pulsed high magnetic field laboratory is to be funded and established at Huazhong University of Science and Technology (HUST), Wuhan, China by the Chinese Development and Reform Committee. In order to cover a wide spectrum of the experimental possibilities, the pulsed field coils are planned in the range of 50-80 T with pulse durations from 20 ms to 1000 ms. Experience in the construction of the pulsed power supplies, pulsed magnet and the experimental equipment has been gained from a pilot laboratory at HUST since 2002. The lab building and the installation of a 1 MJ, 25 kV capacitor bank and the 100 MVA pulse generator have been completed. Two pulsed magnets with a 18 mm bore were made at KU.Leuven in the context of the bilateral project between two universities. The magnets have been tested to 42 T and installed in two measuring stations. As the first experiment, the magneto-resistance of the high temperature superconductor La2-xSrxCuO4 was measured.
{"title":"Development of a Pulsed High Magnetic Field Laboratory at Huazhong University of Science and Technology","authors":"Cheng Wang, X. Duan, K. Yu, T. Peng, Z. Xia, H. Ding, L. Li, F. Herlach, J. Vanacken","doi":"10.1109/MEGAGUSS.2006.4530684","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530684","url":null,"abstract":"A pulsed high magnetic field laboratory is to be funded and established at Huazhong University of Science and Technology (HUST), Wuhan, China by the Chinese Development and Reform Committee. In order to cover a wide spectrum of the experimental possibilities, the pulsed field coils are planned in the range of 50-80 T with pulse durations from 20 ms to 1000 ms. Experience in the construction of the pulsed power supplies, pulsed magnet and the experimental equipment has been gained from a pilot laboratory at HUST since 2002. The lab building and the installation of a 1 MJ, 25 kV capacitor bank and the 100 MVA pulse generator have been completed. Two pulsed magnets with a 18 mm bore were made at KU.Leuven in the context of the bilateral project between two universities. The magnets have been tested to 42 T and installed in two measuring stations. As the first experiment, the magneto-resistance of the high temperature superconductor La2-xSrxCuO4 was measured.","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":"131995872","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.2006.4530675
V. Makhin, M. Angelova, T. Awe, B. Bauer, S. Fuelling, I. Lindemuth, R. Siemon
The surface response to MG fields is important for eventual Magnetized Target Fusion (MTF) experiments " . Recent radiation-hydro numerical simulations in a planar geometry by Garanin et al. show how plasma can be generated through thermal processes on a metal surface. Experiments to study metal plasma formation and stability on the surface of typical liner materials in the MG regime are underway at the University of Nevada at Reno (UNR). Additional experiments on larger facilities such as Atlas and Shiva Star are also planned. We present here our initial modeling of the surface response of aluminum cylindrical conductors, assuming experimentally relevant current rise-times, which determine the ratio of current skin depth relative to conductor radius. Important effects include plasma formation, radiation transport, and the unstable m=0 mode driven by curvature of the magnetic field that holds the surface plasma against the metal. The sensitivity of results to various equation-of-state and resistivity models is also discussed.
{"title":"Modeling of Plasma Formation and Evolution on the Surface of Ohmically Heated Conductors","authors":"V. Makhin, M. Angelova, T. Awe, B. Bauer, S. Fuelling, I. Lindemuth, R. Siemon","doi":"10.1109/MEGAGUSS.2006.4530675","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530675","url":null,"abstract":"The surface response to MG fields is important for eventual Magnetized Target Fusion (MTF) experiments \" . Recent radiation-hydro numerical simulations in a planar geometry by Garanin et al. show how plasma can be generated through thermal processes on a metal surface. Experiments to study metal plasma formation and stability on the surface of typical liner materials in the MG regime are underway at the University of Nevada at Reno (UNR). Additional experiments on larger facilities such as Atlas and Shiva Star are also planned. We present here our initial modeling of the surface response of aluminum cylindrical conductors, assuming experimentally relevant current rise-times, which determine the ratio of current skin depth relative to conductor radius. Important effects include plasma formation, radiation transport, and the unstable m=0 mode driven by curvature of the magnetic field that holds the surface plasma against the metal. The sensitivity of results to various equation-of-state and resistivity models is also discussed.","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":"129660297","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.2006.4530688
J. Goforth, H. Oona, D. Herrera, R. Meyer, D. Tasker, D. Torres
The design and performance of the MK-IX generator was originally published by Fowler and others in the 1989 IEEE Pulsed Power Conference in Monterey, CA. This was a versatile generator that was used for many experiments during the 1980s and 1990s. During that period, we delivered up to 30 MA current to a 35 nH load, and routinely delivered 21 MA to 72 nH inductive stores (16 MJ) for Procyon tests. New research efforts now need the output of a generator of this size, or larger. Our first step is to fabricate generators and demonstrate that we can reproduce old results. We have shown that we can still deliver 460 kA to the generator (7.2 muH) as before. We intend to modernize the MK-IX after establishing baseline performance. Castable explosives have become an efficient driver for generator armatures, but these explosives have reduced performance. To obtain the same output, we will have to modify the generator armature. For example, an aluminum armature could help compensate for explosive performance, and improve both cost and manufacturability. Calculations can compare the baseline design with more practical ones for future use. In this paper we present proposed changes, the pros and cons, and the status of our baseline fabrication and testing efforts.
MK-IX发生器的设计和性能最初由Fowler和其他人在1989年加利福尼亚州蒙特雷举行的IEEE脉冲功率会议上发表。这是一种多功能发生器，在20世纪80年代和90年代用于许多实验。在此期间，我们为35 nH负载提供了高达30 MA的电流，并常规为Procyon测试提供了21 MA至72 nH的电感存储(16 MJ)。现在，新的研究工作需要这种大小或更大的发电机的输出。我们的第一步是制造发电机，并证明我们可以重现旧的结果。我们已经证明，我们仍然可以像以前一样向发电机提供460 kA (7.2 muH)。我们打算在建立基准性能后对MK-IX进行现代化改造。可浇注炸药已成为发电机电枢的有效驱动器，但这些炸药降低了性能。为了获得同样的输出，我们必须修改发电机的电枢。例如，铝电枢可以帮助补偿爆炸性能，并提高成本和可制造性。计算可以将基线设计与将来使用的更实际的设计进行比较。在本文中，我们提出了建议的变更，优点和缺点，以及我们的基线制造和测试工作的状态。
{"title":"Modernization of the MK-IX Generator","authors":"J. Goforth, H. Oona, D. Herrera, R. Meyer, D. Tasker, D. Torres","doi":"10.1109/MEGAGUSS.2006.4530688","DOIUrl":"https://doi.org/10.1109/MEGAGUSS.2006.4530688","url":null,"abstract":"The design and performance of the MK-IX generator was originally published by Fowler and others in the 1989 IEEE Pulsed Power Conference in Monterey, CA. This was a versatile generator that was used for many experiments during the 1980s and 1990s. During that period, we delivered up to 30 MA current to a 35 nH load, and routinely delivered 21 MA to 72 nH inductive stores (16 MJ) for Procyon tests. New research efforts now need the output of a generator of this size, or larger. Our first step is to fabricate generators and demonstrate that we can reproduce old results. We have shown that we can still deliver 460 kA to the generator (7.2 muH) as before. We intend to modernize the MK-IX after establishing baseline performance. Castable explosives have become an efficient driver for generator armatures, but these explosives have reduced performance. To obtain the same output, we will have to modify the generator armature. For example, an aluminum armature could help compensate for explosive performance, and improve both cost and manufacturability. Calculations can compare the baseline design with more practical ones for future use. In this paper we present proposed changes, the pros and cons, and the status of our baseline fabrication and testing efforts.","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":"129701622","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.2006.4530659
S. Garanin, V. Mamyshev, V. B. Yakubov
The research area known as MAGO (Russian abbreviation for magnetic implosion) in Russia and as MTF (Magnetized Target Fusion) in the United States is an alternative to the main CTF approaches (magnetic confinement systems and inertial confinement fusion). The MAGO/MTF approach consists of two phases: 1. First magnetized hot plasma is produced suitable for further compression (with magnetic field ~0.1 MGs having a closed field line configuration; the plasma is of density ~10 cm-3, temperature -300 eV, and small impurity content, as impurities can contribute to the losses caused by radiation). 2. Then the plasma is compressed in the quasi-adiabatic manner by liners (at velocities on the order of 1 cm/mus) using powerful drivers (e. g., explosive magnetic generators, EMG) and its parameters are brought to the ones meeting the Lawson criterion. Here it is necessary to provide the plasma lifetime of ~10-5 s . To implement this approach, it is necessary to combine two essential elements: hot magnetized plasma generation system and highly energetic compression system. In the MAGO chambers, DT plasma of the following parameters has been produced in a cylindrical bulk with 5-8 cm height, 6-10 cm outer radius, and 0.9-1.2 cm inner radius: average density 8ldr10 cm-3 , average temperature 200-250 eV , characteristic azimuthal magnetic field in the plasma ~0.15 MG . In the joint VNIIEF/LANL experiment HEL-1 a liner with the parameters (~25 MJ energy, ~0.8 cm/mus velocity) necessary to reach ignition at compression stage was obtained. As ID and 2D computations of pure plasma compression by a liner with the parameters close to those in the experiment HEL-1 show, the plasma with the characteristics corresponding to the Lawson criterion can be produced in this case. However, the data obtained in preliminary heating experiments using X-ray diodes, suggests ~2-3 mus plasma lifetime, which is insufficient to ensure the ignition in compression. Basing on the computed and experimental data one can conclude that the most important mechanism that contributes to MAGO plasma cooling is contamination of the plasma with impurities and it's cooling due to irradiation on impurities. This plasma contamination can result from the plasma mixing with the insulator vapors (which can be produced from //-pushed discharge) and wall material washout by the plasma. During the plasma compression in the MAGO chamber the mass washed out from the chamber walls can be even larger than that at the preheating phase. So light materials (carbon, beryllium or lithium for walls, beryllium oxide, boron carbide, boron nitride for insulator) should be used in experiments on DT plasma compression in the MAGO chamber. Using light materials for the chamber walls and insulator can increase the plasma lifetime and make the plasma suitable for the liner-plasma experiments.
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