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3D Magneto-Hydrodynamic Modeling of an Overstressed Helical Magnetic Flux Compression Generator
A.J. Johnson;A.J. Young;A.D. White;J.B. Javedani;R.A. Richardson;J.M. Solberg
2019 IEEE Pulsed Power & Plasma Science (PPPS)
Year: 2019 | Conference Paper |
Lawrence Livermore National Laboratory (LLNL) is actively engaged in an experimental program using two-stage magnetic flux compression generators (MFCGs) as pulsed power sources for equation of state measurements [1], [2]. These MFCGs amplify a current pulse in two stages. The first stage uses a helical MFCG and the second stage uses a coaxial MFCG. In support of this program, LLNL recently conduc...Show More
On the Results of an Experiment with a Megajoule Class Helical Flux Compression Generator Operating at Above Nominal Levels of Current and Voltage Stress
A. J. Young;A. D. White;J. J. Trueblood;A.W. Lodes;H. K. Loey;R.A. Richardson;A.J. Johnson;D.P. Milhous;A.J. Ferriera;R.D. Speer;E.V. Baluyot;A. Bockman;R.K. Hicks;K.M. Hood;J.B. Javedani;S.D. Leahy;T.T. Leever;G.R. Mease;D.B. Norton;A.M. Pearson;A.CS. Ray;M.E. Tillman;D. H. Herrera;P. Dickson;J. A. Gunderson
2018 16th International Conference on Megagauss Magnetic Field Generation and Related Topics (MEGAGAUSS)
Year: 2018 | Conference Paper |
Cited by: Papers (2)
An experiment conducted with a megajoule class helical flux compression generator (HFCG), operating into a primarily inductive load, is described. The motivation behind the experiment was to benchmark the performance of the generator at higher currents and voltages than were tested in prior experiments. The intention was to push operation into a regime where flux loss was likely to become nonlinea...Show More
On the Results of an Experiment with a Megajoule Class Helical Flux Compression Generator Operating at Above Nominal Levels of Current and Voltage Stress
A. J. Young;A. D. White;J. J. Trueblood;A.W. Lodes;H. K. Loey;R.A. Richardson;A.J. Johnson;D.P. Milhous;A.J. Ferriera;R.D. Speer;E.V. Baluyot;A. Bockman;R.K. Hicks;K.M. Hood;J.B. Javedani;S.D. Leahy;T.T. Leever;G.R. Mease;D.B. Norton;A.M. Pearson;A.CS. Ray;M.E. Tillman;D. H. Herrera;P. Dickson;J. A. Gunderson
Year: 2018 | Conference Paper |
A Small D-dot for Use on Flux Compression Generators
R. A. Richardson;A.J. Johnson;A. D. White;A. J. Young;J. J. Trueblood;J. B. Javidani;D. P. Milhous;T. J. Ferriera
2018 16th International Conference on Megagauss Magnetic Field Generation and Related Topics (MEGAGAUSS)
Year: 2018 | Conference Paper |
Cited by: Papers (1)
A D-dot voltage probe was designed and tested on a megajoule class flux compression generator (FCG) to measure the voltage on the generator load. Design calculations will be shown, along with experimental data taken from laboratory prototype testing as well as the explosive FCG experiment. The D-dot was terminated in a high impedance amplifier, so that the D-dot is mostly self-integrating (i.e. a ...Show More
Development of the vacuum power flow channel for the Mini-G
J. B. Javedani;D. A. Goerz;D. B. Reisman;T. L. Houck;M. P. Perkins;R. A. Richardson;G. E. Vogtlin
2012 14th International Conference on Megagauss Magnetic Field Generation and Related Topics (MEGAGAUSS)
Year: 2012 | Conference Paper |
Cited by: Papers (1)
The Mini-G explosive pulsed power system is a two-stage helical-coaxial FCG that is geometrically a half-scale version of LLNL's FFT device. The generator is capable of delivering 60 MA currents and 10 MJ of energy to suitable inductive loads. The Mini-G is presently used in high-energy-density physics experiments that require efficient current delivery through a vacuum power flow region to the lo...Show More
Initial LSP simulations of electron beam transport in gas filled drift cells and comparison with experiments performed on the eta II linear induction acceleration at LLNL
David Short;Graham Cooper;Ian Crotch;Gary Guethlein;John Weir;Steve Falabella;Roger Richardson;Stephen Sampayan
2008 17th International Conference on High Power Particle Beams (BEAMS)
Year: 2008 | Conference Paper |
The Pulsed Power group at AWE are using the LSP (Large-Scale-Plasma) code to support the design of X-radiographic diodes for the forthcoming facility Hydrus. Part of the design process requires validation of LSP through various experiments. The aim of the work here is to demonstrate LSP's ability to model electron beam transport through gas cells. Previous work suggests the electron beam focuses i...Show More
Initial LSP simulations of electron beam transport in gas filled drift cells and comparison with experiments performed on the eta II linear induction acceleration at LLNL
David Short;Graham Cooper;Ian Crotch;Gary Guethlein;John Weir;Steve Falabella;Roger Richardson;Stephen Sampayan
Year: 2008 | Conference Paper |
Commissioning the DARHT-II scaled accelerator downstream transport
Martin Schulze;E. O. Abeyta;P. Aragon;R. Archuleta;J. Barraza;D. Dalmas;C. Ekdahl;K. Esquibel;S. Eversole;R. Gallegos;J. Harrison;J. Johnson;E. Jacquez;P. Marroquin;B. Trent McCuistian;R. Mitchell;N. Montoya;S. Nath;L. Rowton;R. Scarpetti;M. Schauer;R. Anaya;G. Caporaso;F. Chambers;Y.J. Chen;S. Falabella;G. Guethlein;J. McCarrick;B. Raymond;R. Richardson;J. Watson;J. Weir;H. Bender;W. Broste;C. Carlson;D. Frayer;D. Johnson;A. Tipton;C. Y. Tom;T. C. Genoni;T. P. Hughes;C. Thoma
The DARHT-II accelerator [1] will produce a 2-kA, 17-MeV beam in a 1600-ns pulse when completed this summer. After exiting the accelerator, the pulse is sliced into four short pulses by a kicker and quadrupole septum and then transported for several meters to a tantalum target for conversion to x-rays for radiography. We describe tests of the kicker, septum, transport, and multipulse converter tar...Show More
Commissioning the DARHT-II scaled accelerator downstream transport
Martin Schulze;E. O. Abeyta;P. Aragon;R. Archuleta;J. Barraza;D. Dalmas;C. Ekdahl;K. Esquibel;S. Eversole;R. Gallegos;J. Harrison;J. Johnson;E. Jacquez;P. Marroquin;B. Trent McCuistian;R. Mitchell;N. Montoya;S. Nath;L. Rowton;R. Scarpetti;M. Schauer;R. Anaya;G. Caporaso;F. Chambers;Y.J. Chen;S. Falabella;G. Guethlein;J. McCarrick;B. Raymond;R. Richardson;J. Watson;J. Weir;H. Bender;W. Broste;C. Carlson;D. Frayer;D. Johnson;A. Tipton;C. Y. Tom;T. C. Genoni;T. P. Hughes;C. Thoma
Year: 2007 | Conference Paper |
Parallel Measurement and Modeling of Transport in the Darht II Beamline on ETA II
Frank W. Chambers;Brett A. Raymond;Steven Falabella;Bryan S. Lee;Roger A. Richardson;John T. Weir;Harold A. Davis;Martin E. Schultze
To successfully tune the DARHT II transport beamline requires the close coupling of a model of the beam transport and the measurement of the beam observables as the beam conditions and magnet settings are varied. For the ETA II experiment using the DARHT II beamline components this was achieved using the SUICIDE (Simple User Interface Connecting to an Integrated Data Environment) data analysis env...Show More
DARHT II Scaled Accelerator Tests on the ETA II Accelerator
John T. Weir;Harold A. Anaya;George J. Caporaso;Frank W. Chambers;Yu-jiuan Chen;Steven Falabella;Bryan S. Lee;Arthur C. Paul;Brett A. Raymond;Roger A. Richardson;James A. Watson;Dominic Chan;Harold A. Davis;Lisa A. Day;Raymond D. Scarpetti;Martin E. Schultze;Thomas P. Hughes
The DARHT II accelerator at LANL is preparing a series of preliminary tests at the reduced voltage of 7.8 Me V. The transport hardware between the end of the accelerator and the final target magnet was shipped to LLNL and installed on ETA II. Using the ETA II beam at 5.2 MeV we completed a set of experiments designed reduce start up time on the DARHT II experiments and run the equipment in a confi...Show More
DARHT II Scaled Accelerator Tests on the ETA II Accelerator
John T. Weir;Harold A. Anaya;George J. Caporaso;Frank W. Chambers;Yu-jiuan Chen;Steven Falabella;Bryan S. Lee;Arthur C. Paul;Brett A. Raymond;Roger A. Richardson;James A. Watson;Dominic Chan;Harold A. Davis;Lisa A. Day;Raymond D. Scarpetti;Martin E. Schultze;Thomas P. Hughes
Year: 2005 | Conference Paper |
Time Resolved X-Ray Spot Diagnostic
R. Richardson;G. Guethlein;S. Falabella;F. Chambers;B. Raymond;J. Weir
Proceedings of the 2005 Particle Accelerator Conference
Year: 2005 | Conference Paper |
Cited by: Papers (1)
A diagnostic was developed for the determination of temporal history of an X-ray spot. A pair of thin (0.5 mm) slits image the x-ray spot to a fast scintillator which is coupled to a fast detector, thus sampling a slice of the X-ray spot. Two other scintillators/detectors are used to determine the position of the spot and total forward dose. The slit signal is normalized to the dose and the result...Show More
Electron beam/converter target interactions in radiographic accelerators
J. McCarrick;G. Caporaso;F. Chambers;Y.-J. Chen;S. Falabella;F. Goldin;G. Guethlein;D. Ho;R. Richardson;J. Weir
Proceedings of the 2003 Particle Accelerator Conference
Year: 2003 | Conference Paper |
Cited by: Papers (2)
Linear induction accelerators used in X-ray radiography have single-pulse parameters of the order 20 MeV of electron beam energy, 2 kA of beam current, pulse lengths of 50-100 ns, and spot sizes of 1-2 mm. The thermal energy deposited in a bremsstrahlung converter target made of tantalum from such a pulse is /spl sim/80 kJ/cc, more than enough to bring the target material to a partially ionized st...Show More
Search for backstreaming ion defocusing during a single pulse of a 2 kA relativistic electron beam
E. J. Lauer;G. J. Caporaso;F. W. Chambers;Y-J Chen;S. Falabella;G. Guethlein;J. McCarrick;R. Richardson;S. Sampayan;J. Weir
2002 14th International Conference on High-Power Particle Beams (BEAMS)
Year: 2002 | Conference Paper |
Cited by: Papers (2)
Desorption and subsequent ionization of the monolayers from the vacuum wall of an accelerator system can have a detrimental effect on the performance of the beam transport system. Ions extracted from the resultant plasma neutralize the spacecharge and dynamically perturb the net focusing forces within the beam. To study the effect, a transparent first foil, presumably with contaminants on the surf...Show More
LASNEX simulations of ETA-II and laser target experiments
D. Ho;F. Chambers;Yu-Jiuan Chen;S. Falabella;F. Goldin;G. Guethlein;J. McCarrick;R. Richardson;S. Sampayan;J. Weir
IEEE Conference Record - Abstracts. 2002 IEEE International Conference on Plasma Science (Cat. No.02CH37340)
Year: 2002 | Conference Paper |
Summary form only given, as follows. In order to have confidence in the radiation converter target design for DARHT-II using LASNEX and our equation of state (EOS) for Ta, we need to compare the LASNEX simulations with experimental results from ETA-II and laser target experiments. ETA-II experiments include the following measurements: integrated line density, plasma expansion velocity, temperature...Show More
Beam-target interaction experiments for multipulse bremsstrahlung converters applications
S. Sampayan;R. Buckles;G. Caporaso;F.C. Chambers;Y.-J. Chen;S. Falabella;F. Goldin;G. Guethlein;D. Ho;M. Heino;T. Houck;E. Lauer;J. McCarrick;R. Neurath;P. Pincosy;R. Richardson;D. Sanders;J. Weir
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)
Year: 2001 | Conference Paper |
Cited by: Papers (2)
As part of the Dual Axis Radiography Hydrotest Facility, Phase II (DARHT II) Multipulse Bremsstrahlung Target effort, we have been performing an investigation of (1) the possible adverse effects of backstreaming ion emission from the bremsstrahlung converter target and (2) the hydrodynamic behavior of the target after the electron beam interaction. Theory predictions show that the first effect wou...Show More
Beam-target interaction experiments for bremsstrahlung converter applications
S. Sampayan;R. Buckles;G. Caporaso;Y.-J. Chen;C. Crist;S. Falabella;T. Houck;M. Krogh;J. McCarrick;R. Richardson;D. Sanders;J. Weir;G. Westenskow
Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)
Year: 1999 | Conference Paper |
Cited by: Papers (4)
For multi-pulse radiography facilities, we are investigating the possible adverse effects of (1) backstreaming ion emission from the bremsstrahlung converter target and (2) the interaction of the resultant plasma with the electron beam during subsequent pulses. These effects would primarily manifest themselves in a static focusing system as a rapidly varying X-ray spot. To study these effects, we ...Show More
Optical diagnostics on ETA II for X-ray spot size
Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)
Year: 1999 | Conference Paper |
Gated and streak cameras have been used to look at a high current focused electron beam on a target, and the X-rays produced by that interaction. An optical camera images the optical transition radiation (OTR) from the beam hitting a C target to give focused beam profiles. Blackbody radiation from heavy metal targets is experimentally proven to be dominant, The roll bar technique is used as a thic...
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Show MoreLLNL flash X-ray radiography machine (FXR) double-pulse upgrade diagnostics
Digest of Technical Papers. 11th IEEE International Pulsed Power Conference (Cat. No.97CH36127)
Year: 1997 | Conference Paper |
Cited by: Papers (4)
When the FXR machine was first tuned on the 1980s, a minimal amount of diagnostics was available and consisted mostly of power monitors. During the accelerator upgrade, additional beam diagnostics were added. The sensor upgrades included beam bugs (resistive wall beam motion sensors) and high-frequency B-dot. Even with this suite of measurement tools, tuning was difficult. For the current double-p...Show More
Experiments with the LLNL large-area ICP plasma source
International Conference on Plasma Science (papers in summary form only received)
Year: 1995 | Conference Paper |
Cited by: Papers (1)
Summary form only given, as follows. We have constructed a 30 diameter plasma source chamber to explore the problems associated with large-area inductively coupled plasma (ICP) sources with a view towards sources useful for 400 mm semiconductor wafer processing. Our initial source design experiments use a 25 diameter planar inductive coil driven at 13.56 MHz. Plasma data is taken in Ar and N/sub 2...
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Show MorePerformance Of A 10 KV, 625 KA, 85 KJ Energy Discharge Module Utilizing A Solid Dielectric Switch
Eighth IEEE International Conference on Pulsed Power
Year: 1991 | Conference Paper |
Cited by: Papers (4)
We have designed and tested an 87-0 energy dis charge system consisting of two 720-/spl mu/F, 11-kV capacitors discharged through parallel coaxial cables into a 250 nH load. Data will be presented on the current and voltage waveforms, with calculated values of the system in ductance and resistance. The bank uses a solid dielectric switch punctured by an explosive bridge wire (EBW) to initiate the ...Show More
An experiment on electron beam transport in an array of wires
7th Pulsed Power Conference
Year: 1989 | Conference Paper |
We have investigated experimentally the propagation of a relativistic electron beam through an array of parallel conducting wires. Theory and particle simulation predict such an array will provide both charge and current neutralization, allowing beam transport above the drift tube limit. We injected a 60ns, l7kA (12OA/cm/sup 2/ )pulse of 1.4 MeV electrons into an array of 1 m long wires spaced 1 c...
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