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Hoffman AL, Milroy RD, Slough JT, Steinhauer LC. Formation of Field-Reversed Configurations Using Scalable, Low-Voltage Technology. ACTA ACUST UNITED AC 2017. [DOI: 10.13182/fst86-a24700] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Alan L. Hoffman
- Spectra Technology, Inc. (formerly Mathematical Sciences Northwest, Inc.) 2755 Northup Way, Bellevue, Washington 98004
| | - Richard D. Milroy
- Spectra Technology, Inc. (formerly Mathematical Sciences Northwest, Inc.) 2755 Northup Way, Bellevue, Washington 98004
| | - John T. Slough
- Spectra Technology, Inc. (formerly Mathematical Sciences Northwest, Inc.) 2755 Northup Way, Bellevue, Washington 98004
| | - Loren C. Steinhauer
- Spectra Technology, Inc. (formerly Mathematical Sciences Northwest, Inc.) 2755 Northup Way, Bellevue, Washington 98004
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Momota H, Ishida A, Kohzaki Y, Miley GH, Ohi S, Ohnishi M, Sato K, Steinhauer LC, Tomita Y, Tuszewski M. Conceptual Design of the D-3He Reactor Artemis. ACTA ACUST UNITED AC 2017. [DOI: 10.13182/fst92-a29724] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hiromu Momota
- National Institute for Fusion Science Nagoya 464-01, Japan
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Guo HY, Hoffman AL, Steinhauer LC, Miller KE, Milroy RD. Evidence of relaxation and spontaneous transition to a high-confinement state in high-beta steady-state plasmas sustained by rotating magnetic fields. Phys Rev Lett 2006; 97:235002. [PMID: 17280209 DOI: 10.1103/physrevlett.97.235002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Indexed: 05/13/2023]
Abstract
Evidence of relaxation has appeared, for the first time, in the extremely high-beta, steady-state field-reversed configuration plasma states driven by rotating magnetic fields (RMF) in the translation, confinement, and sustainment experiment. The plasma self-organizes into a near-force-free state in the vicinity of the magnetic axis, with significant improvement in confinement. Associated with this change in magnetic topology is the appearance of an axial RMF component; this would, in turn, generate a current drive in the poloidal direction, thus sustaining the magnetic helicity. A newly developed two-dimensional "equilibrium-lite" model is employed to analyze the magnetic properties of the final high-confinement state, and shows a large q and a significant magnetic shear in the core.
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Affiliation(s)
- H Y Guo
- Redmond Plasma Physics Laboratory, University of Washington, Seattle, Washington 98195, USA
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Steinhauer LC, Guo H, Ishida A. Computation of Equilibria of a Flowing Two-fluid in Two Dimensions. J Fusion Energ 2006. [DOI: 10.1007/s10894-006-9075-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kimura WD, Andreev NE, Babzien M, Ben-Zvi I, Cline DB, Dilley CE, Gottschalk SC, Hooker SM, Kusche KP, Kuznetsov SV, Pavlishin IV, Pogorelsky IV, Pogosova AA, Steinhauer LC, Ting A, Yakimenko V, Zigler A, Zhou F. Inverse free electron lasers and laser wakefield acceleration driven by CO2 lasers. Philos Trans A Math Phys Eng Sci 2006; 364:611-22. [PMID: 16483952 DOI: 10.1098/rsta.2005.1726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The staged electron laser acceleration (STELLA) experiment demonstrated staging between two laser-driven devices, high trapping efficiency of microbunches within the accelerating field and narrow energy spread during laser acceleration. These are important for practical laser-driven accelerators. STELLA used inverse free electron lasers, which were chosen primarily for convenience. Nevertheless, the STELLA approach can be applied to other laser acceleration methods, in particular, laser-driven plasma accelerators. STELLA is now conducting experiments on laser wakefield acceleration (LWFA). Two novel LWFA approaches are being investigated. In the first one, called pseudo-resonant LWFA, a laser pulse enters a low-density plasma where nonlinear laser/plasma interactions cause the laser pulse shape to steepen, thereby creating strong wakefields. A witness e-beam pulse probes the wakefields. The second one, called seeded self-modulated LWFA, involves sending a seed e-beam pulse into the plasma to initiate wakefield formation. These wakefields are amplified by a laser pulse following shortly after the seed pulse. A second e-beam pulse (witness) follows the seed pulse to probe the wakefields. These LWFA experiments will also be the first ones driven by a CO(2) laser beam.
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Affiliation(s)
- W D Kimura
- STI Optronics, Inc. Bellevue, WA 98004-1495, USA.
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Guo HY, Hoffman AL, Steinhauer LC, Miller KE. Observations of improved stability and confinement in a high-beta self-organized spherical-torus-like field-reversed configuration. Phys Rev Lett 2005; 95:175001. [PMID: 16383833 DOI: 10.1103/physrevlett.95.175001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Indexed: 05/05/2023]
Abstract
An extremely high-beta (over 85%) self-organized field-reversed configuration (FRC) with a spherical-torus- (ST-)like core is produced in the translation, confinement, and sustainment experiment by highly super-Alfvénic translation of a spheromaklike plasmoid. Substantial flux conversion from toroidal into poloidal occurs during the capture process, resulting in the ST-like core. This plasma state exhibits a remarkable stabilizing property for the ubiquitous centrifugally driven interchange modes present in theta-pinch formed FRCs. This is explained, for the first time, by a simple model taking into account magnetic shear and centrifugal effects. The FRC-ST configuration has up to 4 times improvement in flux confinement times over the scaling of conventional theta-pinch formed FRCs and, thus, a significant improvement in the resistivity and transport.
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Affiliation(s)
- H Y Guo
- Redmond Plasma Physics Laboratory, University of Washington, Seattle, Washington 98195, USA
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Guo HY, Hoffman AL, Miller KE, Steinhauer LC. Flux conversion and evidence of relaxation in a high-beta plasma formed by high-speed injection into a mirror confinement structure. Phys Rev Lett 2004; 92:245001. [PMID: 15245090 DOI: 10.1103/physrevlett.92.245001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2003] [Revised: 08/14/2003] [Indexed: 05/24/2023]
Abstract
High-beta plasmoids can survive the violent dynamics of supersonic reflection off mirror structures, producing a stable high-beta field-reversed configuration (FRC). This shows both the robustness of FRCs and their tendency to assume a preferred plasma state, possibly conforming to a relaxation principle. The key observations are (1) approximate preservation of the magnetic helicity, (2) substantial conversion from toroidal to poloidal magnetic flux, (3) substantial toroidal flow, and (4) a high-beta quiescent final state. These results are from the Translation, Confinement, and Sustainment experiment where a disorganized plasmoid is injected at super-Alfvenic speed into a confinement chamber. After successive reflections from end mirrors, the plasmoid settled into a near-FRC state with high beta and low toroidal magnetic field. The flux conversion and helicity preservation are inferred by an interpretive model.
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Affiliation(s)
- H Y Guo
- Redmond Plasma Physics Laboratory, University of Washington, Seattle, Washington 98195, USA
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Kimura WD, Babzien M, Ben-Zvi I, Campbell LP, Cline DB, Dilley CE, Gallardo JC, Gottschalk SC, Kusche KP, Pantell RH, Pogorelsky IV, Quimby DC, Skaritka J, Steinhauer LC, Yakimenko V, Zhou F. Demonstration of high-trapping efficiency and narrow energy spread in a laser-driven accelerator. Phys Rev Lett 2004; 92:054801. [PMID: 14995313 DOI: 10.1103/physrevlett.92.054801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2003] [Revised: 01/23/2004] [Indexed: 05/24/2023]
Abstract
Laser-driven electron accelerators (laser linacs) offer the potential for enabling much more economical and compact devices. However, the development of practical and efficient laser linacs requires accelerating a large ensemble of electrons together ("trapping") while keeping their energy spread small. This has never been realized before for any laser acceleration system. We present here the first demonstration of high-trapping efficiency and narrow energy spread via laser acceleration. Trapping efficiencies of up to 80% and energy spreads down to 0.36% (1 sigma) were demonstrated.
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Affiliation(s)
- W D Kimura
- STI Optronics, Inc., Bellevue, Washington 98004, USA.
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Kimura WD, van Steenbergen A, Babzien M, Ben-Zvi I, Campbell LP, Cline DB, Dilley CE, Gallardo JC, Gottschalk SC, He P, Kusche KP, Liu Y, Pantell RH, Pogorelsky IV, Quimby DC, Skaritka J, Steinhauer LC, Yakimenko V. First staging of two laser accelerators. Phys Rev Lett 2001; 86:4041-4043. [PMID: 11328090 DOI: 10.1103/physrevlett.86.4041] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2000] [Revised: 03/15/2001] [Indexed: 05/23/2023]
Abstract
Staging of two laser-driven, relativistic electron accelerators has been demonstrated for the first time in a proof-of-principle experiment, whereby two distinct and serial laser accelerators acted on an electron beam in a coherently cumulative manner. Output from a CO2 laser was split into two beams to drive two inverse free electron lasers (IFEL) separated by 2.3 m. The first IFEL served to bunch the electrons into approximately 3 fs microbunches, which were rephased with the laser wave in the second IFEL. This represents a crucial step towards the development of practical laser-driven electron accelerators.
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Affiliation(s)
- W D Kimura
- STI Optronics, Inc., Bellevue, Washington 98004, USA.
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