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Status report on the conceptual design of a commercial tokamak hybrid reactor (CTHR)

Description: A preliminary conceptual design is presented for an early twenty-first century fusion hybrid reactor called the Commercial Tokamak Hybrid Reactor (CTHR). This design was developed as a first generation commercial plant producing fissile fuel to support a significant number of client Light Water Reactor (LWR) plants. The study has been made in sufficient depth to indicate no insurmountable technical problems exist and has provided a basis for valid cost estimates of the hybrid plants as well as the hybrid/LWR system busbar electricity costs. This energy system can be optimized to have a net cost of busbar electricity that is equivalent to the conventional LWR plant, yet is not dependent on uranium ore prices or standard enrichment costs, since the fusion hybrid can be fueled by numerous fertile fuel resources.
Date: September 1, 1979
Partner: UNT Libraries Government Documents Department

Progress in the study of mesh refinement for particle-in-cell plasma simulations and its application to heavy ion fusion

Description: The numerical simulation of the driving beams in a heavy ion fusion power plant is a challenging task, and, despite rapid progress in computer power, one must consider the use of the most advanced numerical techniques. One of the difficulties of these simulations resides in the disparity of scales in time and in space which must be resolved. When these disparities are in distinctive zones of the simulation region, a method which has proven to be effective in other areas (e.g. fluid dynamics simulations) is the Adaptive-Mesh-Refinement (AMR) technique. We follow in this article the progress accomplished in the last few months in the merging of the AMR technique with Particle-In-Cell (PIC) method. This includes a detailed modeling of the Lampel-Tiefenback solution for the one-dimensional diode using novel techniques to suppress undesirable numerical oscillations and an AMR patch to follow the head of the particle distribution. We also report new results concerning the modeling of ion sources using the axisymmetric WARPRZ-AMR prototype showing the utility of an AMR patch resolving the emitter vicinity and the beam edge.
Date: September 15, 2002
Creator: Vay, J.-L.; Friedman, A. & Grote, D.P.
Partner: UNT Libraries Government Documents Department

Arc-Discharge Ion Sources for Heavy Ion Fusion

Description: A miniature multiple beamlet approach to an injector system was recently proposed in order to reduce the size, cost, and power requirements of the injector. The beamlets of very high current density are needed to meet the brightness requirement. Besides vacuum arc ion sources, cold-cathode gas ion sources are candidates for this application. Vacuum-arc metal ion sources and vacuum-arc-like gas ion sources are discussed. Experiments are presented that focus on the short-pulse plasma composition and ion charge state distribution. Mg and Sr have been identified as the most promising metals leading to mono-species beams when 20 {mu}s arc pulses are used. It is shown that the efficient production of gas ions requires the presence of a magnetic field.
Date: March 1, 2000
Creator: Anders, A. & Kwan, J.W.
Partner: UNT Libraries Government Documents Department

The Heavy Ion Fusion Program in the USA

Description: The U.S. Department of Energy has established a new, larger inertial fusion energy program. To manage program growth, we have developed a new inertial fusion energy research and we have established a Virtual National Laboratory for Heavy Ion Fusion. There has been significant technical progress. Improvements in target design have reduced the predicted energy requirements by approximately a factor of two. There have also been important experiments on chamber dynamics and other inertial fusion technologies. The accelerator program has completed a number of small-scale experiments. Experiments with driver-scale beams are being designed -- including experiments with driver-scale ion sources and injectors. Finally we are developing the technologies needed to build a major research facility known as the Integrated Research Experiment (IRE)
Date: March 17, 2000
Creator: Bangerter, R.O.
Partner: UNT Libraries Government Documents Department

Fusion Materials Semiannual Progress Report for Period Ending December 31, 1998

Description: This is the twenty-fifth in a series of semiannual technical progress reports on fusion materials. This report combines the full spectrum of research and development activities on both metallic and non-metallic materials with primary emphasis on the effects of the neutronic and chemical environment on the properties and performance of materials for in-vessel components. This effort forms one element of the materials program being conducted in support of the Fusion Energy Sciences Program of the U.S. Department of Energy. The other major element of the program is concerned with the interactions between reactor materials and the plasma and is reported separately.
Date: April 1, 1999
Creator: Rowcliff, A.F. & Burn, G.
Partner: UNT Libraries Government Documents Department

Beam imaging diagnostics for heavy ion beam fusion experiments

Description: We are developing techniques for imaging beams in heavy-ion beam fusion experiments in the HIF-VNL in 2 to 4 transverse dimensions. The beams in current experiments range in energy from 50 keV to 2 MeV, with beam current densities from <10 to 200 mA/cm{sup 2}, and pulse lengths of 4 to 20 {micro}s. The beam energy will range up to 10 MeV in near-future beam experiments. The imaging techniques, based on kapton films and optical scintillators, complement and, in some cases, may replace mechanical slit scanners. The kapton film images represent a time-integrated image on the film exposed to the beam. The optical scintillator utilizes glass and ceramic scintillator material imaged by a fast, image-intensified CCD-based camera. We will discuss the techniques, results, and plans for implementation of the diagnostics on the beam experiments.
Date: May 1, 2003
Creator: Bieniosek, F.M.; Prost, L. & Ghiorso, W.
Partner: UNT Libraries Government Documents Department

Developing high brightness and high current beams for HIF injectors

Description: The US Heavy Ion Fusion Virtual National Laboratory is continuing research into ion sources and injectors that simultaneously provide high current (0.5-1.0 Amps) and high brightness (normalized emittance better than 1.0 {pi}-mm-mr). The central issue of focus is whether to continue pursuing the traditional approach of large surface ionization sources or to adopt a multiaperture approach that transports many smaller ''beamlets'' separately at low energies before allowing them to merge. For the large surface source concept, the recent commissioning of the 2-MeV injector for the High Current eXperiment has increased our understanding of the beam quality limitations for these sources. We have also improved our techniques for fabricating large diameter aluminosilicate sources to improve lifetime and emission uniformity. For the multiaperture approach, we are continuing to study the feasibility of small surface sources and a RF induced plasma source in preparation for beamlet merging experiments, while continuing to run computer simulations for better understanding of this alternate concept. Experiments into both architectures will be performed on a newly commissioned ion source test stand at LLNL called STS-500. This stand test provides a platform for testing a variety of ion sources and accelerating structures with 500 kV, 17-microsecond pulses. Recent progress in these areas will be discussed as well as plans for future experiments.
Date: May 24, 2002
Creator: Ahle, Larry; Grote, Dave & Kwan, Joe
Partner: UNT Libraries Government Documents Department

Asymmetric PML for the absorption of waves. Application to mesh refinement in electromagnetic particle-in-cell plasma simulations

Description: We present an extension of the Berenger Perfectly Matched Layer with additional terms and tunable coefficients which introduce some asymmetry in the absorption rate. We show that the discretized version of the new PML offers superior absorption rates than the discretized standard PML under a plane wave analysis. Taking advantage of the high rates of absorption of the new PML, we have devised a new strategy for introducing the technique of Mesh Refinement into electromagnetic Particle-In-Cell plasma simulations. We present the details of the algorithm as well as a 2-D example of its application to laser-plasma interaction in the context of fast ignition.
Date: September 24, 2003
Creator: Vay, J.-L.; Adam, J.-C. & Heron, A.
Partner: UNT Libraries Government Documents Department

Analytical study of envelope modes for a fully depressed beam in solenoidal and quadrupole periodic transport channels

Description: We present an analysis of envelope perturbations evolving in the limit of a fully space-charge depressed (zero emittance) beam in periodic, thin-lens focusing channels. Both periodic solenoidal and FODO quadrupole focusing channels are analyzed. The phase advance and growth rate of normal mode perturbations are analytically calculated as a function of the undepressed particle phase advance to characterize the evolution of envelope perturbations.
Date: May 2003
Creator: Bukh, Boris & Lund, Steven M.
Partner: UNT Libraries Government Documents Department

User's manual for COAST 4: a code for costing and sizing tokamaks

Description: The purpose of this report is to document the computer program COAST 4 for the user/analyst. COAST, COst And Size Tokamak reactors, provides complete and self-consistent size models for the engineering features of D-T burning tokamak reactors and associated facilities involving a continuum of performance including highly beam driven through ignited plasma devices. TNS (The Next Step) devices with no tritium breeding or electrical power production are handled as well as power producing and fissile producing fusion-fission hybrid reactors. The code has been normalized with a TFTR calculation which is consistent with cost, size, and performance data published in the conceptual design report for that device. Information on code development, computer implementation and detailed user instructions are included in the text.
Date: September 1, 1979
Creator: Sink, D. A. & Iwinski, E. M.
Partner: UNT Libraries Government Documents Department

Electrical breakdown studies with Mycalex insulators

Description: Insulating materials such as alumina and glass-bonded mica (Mycalex) are used in accelerator systems for high voltage feedthroughs, structural supports, and barriers between high voltage insulating oil and the vacuum beam pipe in induction accelerator cells. Electric fields in the triple points should be minimized to prevent voltage breakdown. Mechanical stress can compromise seals and result in oil contamination of the insulator surface. We have tested various insulator cleaning procedures including ultrasonic cleaning with a variety of aqueous-based detergents, and manual scrubbing with various detergents. Water sheeting tests were used to determine the initial results of the cleaning methods. Ultimately, voltage breakdown tests will be used to quantify the benefits of these cleaning procedures.
Date: May 1, 2003
Creator: Waldron, W.; Greenway, W.; Eylon, S.; Henestroza, E. & Yu, S.
Partner: UNT Libraries Government Documents Department

Beam Simulations for IRE and Driver-Status and Strategy

Description: The methods and codes employed in the U.S. Heavy Ion Fusion program to simulate the beams in an Integrated Research Experiments (IRE) facility and a fusion driver are presented in overview. A new family of models incorporating accelerating module impedance, multi-beam, and self-magnetic effects is described, and initial WARP3d particle simulations of beams using these models are presented. Finally, plans for streamlining the machine-design simulation sequence, and for simulating beam dynamics from the source to the target in a consistent and comprehensive manner, are described.
Date: March 1, 2000
Creator: Friedman, A.; Grote, D.P.; Lee, E.P. & Sonnendrucker, E.
Partner: UNT Libraries Government Documents Department

Preliminary results from a scaled final focus experiment for heavy ion inertial fusion

Description: Vacuum ballistic focusing may be a straightforward method to obtain the heavy ion beam spot size necessary to drive an inertial confinement fusion target. Proper scaling of particle energy, mass, beam current, beam emittance, and magnetic field replicates the dynamics of a full driver beam in a small laboratory experiment. By expanding the beam and then focusing to a very small spot, the effects of aberrations and space charge on this method of final focus can be studied. To date, 200 {micro}A of 120keV K{sup +} has been focused to test the matching and focusing elements. A recently designed high brightness contact ionization source is being tested for upcoming focusing measurements with an 87 {micro}A Cs beam that will duplicate the dynamics of a proposed driver design at one-tenth scale. Transverse phase space and beam current density at various stages of the focus will be presented. Follow-on measurements studying electron neutralization of space charge and its effect on the focus will be explored.
Date: March 29, 1999
Creator: MacLaren, S.; Faltens, A.; Henestroza, E.; Ritchie, G. & Seidl, P.
Partner: UNT Libraries Government Documents Department

High brightness potassium ion gun for the HIF neutralized transport experiment (NTX)

Description: The NTX experiment at the Heavy Ion Fusion Virtual National Laboratory is exploring the performance of neutralized final focus systems for high perveance heavy ion beams. To focus a high intensity beam to a small spot requires a high brightness beam. In the NTX experiment, a potassium ion beam of up to 400 keV and 80 mA is generated in a Pierce type diode. At the diode exit, an aperture with variable size provides the capability to vary the beam perveance and to significantly reduce the beam emittance. We shall report on the gun characterization including current density profile, phase space distributions and the control of electrons generated by the beam scraping at the aperture. Comparison with particle simulations using the EGUN code will be presented.
Date: May 1, 2003
Creator: Eylon, S.; Henestroza, E.; Roy, P.K. & Yu, S.S.
Partner: UNT Libraries Government Documents Department

Drift compression and final focus of intense heavy ion beams

Description: The longitudinal and transverse dynamics of a heavy ion fusion beam during the drift compression and final focus phase is studied. A lattice design with four time-dependent magnets is described that focuses the entire beam pulse onto a single focal point with the same spot size.
Date: May 2003
Creator: Qin, Hong; Davidson, Ronald C.; Barnard, John J. & Lee, Edward P.
Partner: UNT Libraries Government Documents Department

Fabrication of large diameter alumino-silicate K{sup +} sources

Description: Alumino-silicate K{sup +} sources have been used in HIF experiments for many years. For example the Neutralized Transport Expt. (NTX) and the High Current Transport Expt. (HCX) are now using this type of ion source with diameters of 2.54 cm and 10 cm respectively. These sources have demonstrated ion currents of 80 mA and 700 mA, for typical HIF pulse lengths of 5-10 {micro}s. The corresponding current density is {approx} 10-15 mA/cm{sup 2}, but much higher current density has been observed using smaller size sources. Recently we have improved our fabrication techniques and, therefore, are able to reliably produce large diameter ion sources with high quality emitter surface without defects. This note provides a detailed description of the procedures employed in the fabrication process. The variables in the processing steps affecting surface quality, such as substrate porosity, powder size distribution, coating technique on large area concave surfaces, drying, and heat firing temperature have been investigated.
Date: February 20, 2003
Creator: Baca, D.; Chacon-Golcher, E.; Kwan, J.W. & Wu, J.K.
Partner: UNT Libraries Government Documents Department

Diffusion of alkali species in porous tungsten substrates used in contact-ionization sources

Description: Contact ionization (doped) sources used in current Heavy Ion Fusion (HIF) experiments consist of a porous tungsten substrate doped with an alkali carbonate. During the early stages of the heating cycle (T {approx} 600 C), the carbonate breaks down and releases the alkali atoms that then diffuse through the substrate. At the emitter surface there is a balance between the fast desorption rate of the alkali atoms (mostly as neutrals) and the slower replenishment rate from the substrate by diffusion. Time-resolved measurements of neutral particle evaporation rates at the emitter surface have been used to estimate the effective diffusion coefficient (D) that characterizes the migration of alkali species in the substrate. These estimates are consistent with the observed source lifetimes (tens of hrs.) and establish the alkali migration in the bulk as a diffusion-limited process. The measurements suggest that the faster migration rates (D {approx} 10{sup -5}-10{sup -6} cm{sup 2}/s) occur early during the heating cycle when the dominant species are the neutral alkali atoms. At operating temperatures there is a slower migration rate (D {approx} 10{sup -7} cm{sup 2}/s) due to the dominance of ions, which diffuse by a slower surface diffusion process.
Date: June 1, 2003
Creator: Chacon-Golcher, E.; Kwan, J.W. & Morse, E.C.
Partner: UNT Libraries Government Documents Department

Use of projectional phase space data to infer a 4D particle distribution

Description: We consider beams which are described by a 4D transverse distribution f(x,y,x{prime},y{prime}), where x{prime} {triple_bond} p{sub x}/p{sub z} and z is the axial coordinate. A two-slit scanner is commonly employed to measure, over a sequence of shots, a 2D projection of such a beam's phase space, e.g., f(x,x{prime}). Another scanner might yield f(y,y{prime}) or, using crossed slits, f(x,y). A small set of such 2D scans does not uniquely specify f(x,y,x{prime},y{prime}). We have developed ''tomographic'' techniques to synthesize a ''reasonable'' set of particles in a 4D phase space having 2D densities consistent with the experimental data. These techniques are described in a separate document [A. Friedman, et. al., submitted to Phys. Rev. ST-AB, 2002]. Here we briefly summarize one method and describe progress in validating it, using simulations of the High Current Experiment at Lawrence Berkeley National Laboratory.
Date: May 20, 2002
Creator: Friedman, A.; Grote, D.P.; Celata, C.M. & Staples, J.W.
Partner: UNT Libraries Government Documents Department

A 1.8 Mev K+ injector for the high current beam transport experiment fusion

Description: For the High Current Beam Transport Experiment (HCX) at LBNL, an injector is required to deliver up to 1.8 MV of 0.6 A K{sup +} beam with an emittance of {approx}1 p-mm-mrad. We have successfully operated a 10-cm diameter surface ionization source together with an electrostatic quadrupole (ESQ) accelerator to meet these requirements. The pulse length is {approx}4 {micro}s, firing at once every 10-15 seconds. By optimizing the extraction diode and the ESQ voltages, we have obtained an output beam with good current density uniformity, except for a small increase near the beam edge. Characterization of the beam emerging from the injector included measurements of the intensity profile, beam imaging, and transverse phase space. These data along with comparison to computer simulations provide the knowledge base for designing and understanding future HCX experiments.
Date: May 20, 2002
Creator: Kwan, J.W.; Bieniosek,F.M.; Henestroza, E.; Prost, L. & Seidl, P.
Partner: UNT Libraries Government Documents Department

Final Technical Report

Description: Final Technical Report for U.S. Department of Energy Grant No. DE-FG02-09ER55005 Nonlinear FLR Effects in Reduced Fluid Models Alain J. Brizard, Saint Michael™s College The above-mentioned DoE grant was used to support research activities by the PI during a sabbatical leave from Saint Michael™s College in 2009. The major focus of the work was the role played by guiding-center and gyrocenter (linear and nonlinear) polarization and magnetization effects in understanding transport processes in turbulent magnetized plasmas. The theoretical tools used for this work include Lie-transform perturbation methods and Lagrangian (variational) methods developed by the PI in previous work. The present final technical report lists (I) the peer-reviewed publications that were written based on work funded by the Grant; (II) invited and contributed conference presentations during the period funded by the Grant; and (III) seminars presented during the period funded by the Grant. I. Peer-reviewed Publications A.J. Brizard and N. Tronko, 2011, Exact momentum conservation for the gyrokinetic Vlasov- Poisson equations, Physics of Plasmas 18 , 082307:1-14 [http://dx.doi.org/10.1063/1.3625554 ]. J. Decker, Y. Peysson, A.J. Brizard, and F.-X. Duthoit, 2010, Orbit-averaged guiding-center Fokker-Planck operator for numerical applications, Physics of Plasmas 17, 112513:1-12 [http://dx.doi.org/10.1063/1.3519514]. A.J. Brizard, 2010, Noether derivation of exact conservation laws for dissipationless reduced fluid models, Physics of Plasmas 17, 112503:1-8 [http://dx.doi.org/10.1063/1.3515303]. F.-X. Duthoit, A.J. Brizard, Y. Peysson, and J. Decker, 2010, Perturbation analysis of trapped particle dynamics in axisymmetric dipole geometry, Physics of Plasmas 17, 102903:1-9 [http://dx.doi.org/10.1063/1.3486554]. A.J. Brizard, 2010, Exact energy conservation laws for full and truncated nonlinear gyrokinetic equations, Physics of Plasmas 17, 042303:1-11 [http://dx.doi.org/10.1063/1.3374428]. A.J. Brizard, J. Decker, Y. Peysson, and F.-X. Duthoit, 2009, Orbit-averaged guiding-center Fokker-Planck operator, Physics of Plasmas 16, 102304:1-9[http://dx.doi.org/10.1063/1.3249627]. A.J. Brizard, 2009, Variational Principles for Reduced Plasma Physics, Journal of Physics: Conference Series 169, 012003 [http://dx.doi.org/10.1088/1742-6596/169/1/012003]. II. Invited and Contributed Conference Presentations A.J. ...
Date: 2009
Creator: Brizard, Alain J.
Partner: UNT Libraries Government Documents Department

Inertial Fusion Sciences and Applications 2003: State of the Art 2003, Published by the American Nuclear Society

Description: Collection of all papers presented and submitted at the IFSA2003 conference. Topics included target design and performance, fast ignition, plasma instabilities, laser technology, fusion reactor technology
Date: June 1, 2004
Creator: Hammel, B. A.; Meyerhofer, D. D.; Meyer-ter-Vehn, J. & Hogan, H. Azechi. Organizing Chair: W. J.
Partner: UNT Libraries Government Documents Department

Particle-in-cell simulations of the dynamic Aperture of the HCX

Description: The HIF-VNL High Current Experiment (HCX) [1] is exploring transport issues such as dynamic aperture, effects of quadrupole rotation, and the effects on the beam of non-ideal distribution function, mismatch, and electrons, using one driver-scale 0.2 microcoulomb/m, 2-10 microsecond coasting K{sup +} beam. 2D and 3D simulations are being done, using the particle-in-cell (PIC) code WARP to study these phenomena. We present results which predict that the dynamic aperture in the electrostatic focusing transport section will be set by particle loss.
Date: May 1, 2002
Creator: Celata, C.M.; Friedman, A.F.; Grote, D.P.; Haber, I. & Henestroza, E.
Partner: UNT Libraries Government Documents Department

Magnetic lattice for the HIF neutralized transport experiment (NTX)

Description: The NTX experiment at the Heavy Ion Fusion Virtual National Laboratory is exploring the performance of neutralized final focus systems for high perveance heavy ion beams. A pulsed magnetic four-quadrupole transport system for a 400 keV, 80 mA space charge dominated heavy ion beam has been designed, fabricated, tested, measured, and commissioned successfully for the Neutralized Transport Experiment (NTX). We present some generalized multipole decompositions of 3-D finite element calculations, and 2-D transient finite element simulations of eddy currents in the beam tube. Beam envelope calculations along the transport line were performed using superposition of individually 3-D calculated magnetic field maps. Revised quadrupole design parameters and features, plus fabrication and testing highlights are also presented. Magnetic field measurements were made using both Hall probes (low field DC) and inductive loop coil (high field pulsed). Magnet testing consisted of repetitive full current pulsing to determine reliability.
Date: May 1, 2003
Creator: Shuman, D.; Eylon, S.; Henestroza, E.; Roy, P.K.; Waldron, W.; Yu, S.S. et al.
Partner: UNT Libraries Government Documents Department