scholarly journals Particle-in-cell simulations of the dynamic aperture of the HCX

2002 ◽  
Vol 20 (4) ◽  
pp. 577-579 ◽  
Author(s):  
C.M. CELATA ◽  
D.P. GROTE ◽  
I. HABER
Keyword(s):  
National Laboratory ◽  
Three Dimensional ◽  
Heavy Ion ◽  
High Current ◽  
Current Experiment ◽  
Particle Loss ◽  
Particle In Cell ◽  
Dynamic Aperture ◽  
Heavy Ion Fusion ◽  
Three Dimensional Simulations

The Heavy Ion Fusion Virtual National Laboratory High Current Experiment (HCX) is exploring transport issues such as dynamic aperture, effects of quadrupole rotation, and the effects on the beam of nonideal distribution function, mismatch, and electrons, using one driver-scale 0.2 μC/m, 2–10 μs coasting K+ beam. Two- and three-dimensional simulations are being done, using the particle-in-cell 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.

scholarly journals Overview of theory and modeling in the heavy ion fusion virtual national laboratory

2002 ◽  
Vol 20 (3) ◽  
pp. 377-384 ◽  
Author(s):  
R.C. DAVIDSON ◽  
I.D. KAGANOVICH ◽  
W.W. LEE ◽  
H. QIN ◽  
E.A. STARTSEV ◽  
...  
Keyword(s):  
Ion Beam ◽  
National Laboratory ◽  
Three Dimensional ◽  
Development Program ◽  
Heavy Ion ◽  
Target Chamber ◽  
Temperature Anisotropy ◽  
Particle In Cell ◽  
Beam Experiment ◽  
Heavy Ion Fusion

This article presents analytical and simulation studies of intense heavy ion beam propagation, including the injection, acceleration, transport and compression phases, and beam transport and focusing in background plasma in the target chamber. Analytical theory and simulations that support the High Current Experiment (HCX), the Neutralized Transport Experiment (NTX), and the advanced injector development program, are being used to provide a basic understanding of the nonlinear beam dynamics and collective processes, and to develop design concepts for the next-step Integrated Beam Experiment (IBX), an Integrated Research Experiment (IRE), and a heavy ion fusion driver. Three-dimensional nonlinear perturbative simulations have been applied to collective instabilities driven by beam temperature anisotropy, and to two-stream interactions between the beam ions and any unwanted background electrons; three-dimensional particle-in-cell simulations of the 2-MV electrostatic quadrupole (ESQ) injector have clarified the influence of pulse rise time; analytical studies and simulations of the drift compression process have been carried out; syntheses of a four-dimensional particle distribution function from phase-space projections have been developed; and studies of the generation and trapping of stray electrons in the beam self-fields have been performed. Particle-in-cell simulations, involving preformed plasma, are being used to study the influence of charge and current neutralization on the focusing of the ion beam in NTX and in a fusion chamber.

scholarly journals Progress in the development of superconducting quadrupoles for heavy ion fusion

2002 ◽  
Vol 20 (4) ◽  
pp. 617-620 ◽  
Author(s):  
A. FALTENS ◽  
A. LIETZKE ◽  
G. SABBI ◽  
P. SEIDL ◽  
S. LUND ◽  
...  
Keyword(s):  
Conceptual Design ◽  
National Laboratory ◽  
Quadrupole Doublet ◽  
Heavy Ion ◽  
High Current ◽  
Current Experiment ◽  
Baseline Design ◽  
Fusion Program ◽  
Single Aperture ◽  
Heavy Ion Fusion

The heavy ion fusion program is developing single aperture superconducting quadrupoles based on NbTi conductor, for use in the High Current Experiment at Lawrence Berkeley National Laboratory. Following the fabrication and testing of prototypes using two different approaches, a baseline design has been selected and further optimized. A prototype cryostat for a quadrupole doublet, with features to accommodate induction acceleration modules, is being fabricated. The single aperture magnet was derived from a conceptual design of a quadrupole array magnet for multibeam transport. Progress on the development of superconducting quadrupole arrays for future experiments is also reported.

scholarly journals The high current experiment: First results

2002 ◽  
Vol 20 (3) ◽  
pp. 435-440 ◽  
Author(s):  
P.A. SEIDL ◽  
D. BACA ◽  
F.M. BIENIOSEK ◽  
A. FALTENS ◽  
S.M. LUND ◽  
...  
Keyword(s):  
Space Charge ◽  
Ion Beam ◽  
Beam Steering ◽  
Fusion Energy ◽  
National Laboratory ◽  
Heavy Ion ◽  
High Current ◽  
Current Experiment ◽  
First Results ◽  
High Space

The High Current Experiment (HCX) is being assembled at Lawrence Berkeley National Laboratory as part of the U.S. program to explore heavy ion beam transport at a scale representative of the low-energy end of an induction linac driver for fusion energy production. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge dominated heavy ion beams at high space-charge intensity (line-charge density ∼ 0.2 μC/m) over long pulse durations (>4 μs). This machine will test transport issues at a driver-relevant scale resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and beam steering, matching, image charges, halo, lost-particle induced electron effects, and longitudinal bunch control. We present the first experimental results carried out with the coasting K+ ion beam transported through the first 10 electrostatic transport quadrupoles and associated diagnostics. Later phases of the experiment will include more electrostatic lattice periods to allow more sensitive tests of emittance growth, and also magnetic quadrupoles to explore similar issues in magnetic channels with a full driver scale beam.

scholarly journals Mesh refinement for particle-in-cell plasma simulations: Applications to and benefits for heavy ion fusion

2002 ◽  
Vol 20 (4) ◽  
pp. 569-575 ◽  
Author(s):  
J.-L. VAY ◽  
P. COLELLA ◽  
P. McCORQUODALE ◽  
B. VAN STRAALEN ◽  
A. FRIEDMAN ◽  
...  
Keyword(s):  
Power Plant ◽  
Adaptive Mesh Refinement ◽  
National Laboratory ◽  
Mesh Refinement ◽  
Adaptive Mesh ◽  
Heavy Ion ◽  
Ion Source ◽  
Particle In Cell ◽  
Plasma Simulations ◽  
Heavy Ion Fusion

The numerical simulation of the driving beams in a heavy ion fusion power plant is a challenging task, and simulation of the power plant as a whole, or even of the driver, is not yet possible. Despite the rapid progress in computer power, past and anticipated, one must consider the use of the most advanced numerical techniques, if we are to reach our goal expeditiously. 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 mesh refinement technique. We discuss the challenges posed by the implementation of this technique into plasma simulations (due to the presence of particles and electromagnetic waves). We present the prospects for and projected benefits of its application to heavy ion fusion, in particular to the simulation of the ion source and the final beam propagation in the chamber. A collaboration project is under way at Lawrence Berkeley National Laboratory between the Applied Numerical Algorithms Group (ANAG) and the Heavy Ion Fusion group to couple the adaptive mesh refinement library CHOMBO developed by the ANAG group to the particle-in-cell accelerator code WARP developed by the Heavy Ion Fusion–Virtual National Laboratory. We describe our progress and present our initial findings.

scholarly journals Octopole correction of geometric aberrations for high-current heavy-ion fusion beams

2003 ◽  
Author(s):  
D.D.-M. Ho ◽  
I. Haber ◽  
R. Crandall ◽  
S.T. Brandon
Keyword(s):  
Heavy Ion ◽  
High Current ◽  
Heavy Ion Fusion

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

2003 ◽  
Vol 21 (1) ◽  
pp. 17-20 ◽  
Author(s):  
A. FRIEDMAN ◽  
D.P. GROTE ◽  
C.M. CELATA ◽  
J.W. STAPLES
Keyword(s):  
Experimental Data ◽  
Phase Space ◽  
Particle Distribution ◽  
National Laboratory ◽  
Two Dimensional ◽  
High Current ◽  
Current Experiment ◽  
Axial Coordinate ◽  
Small Set ◽  
Space Data

We consider beams that are described by a four-dimensional (4D) transverse distribution f (x, y, x′, y′), where x′ ≡ px /pz and z is the axial coordinate. A two-slit scanner is commonly employed to measure, over a sequence of shots, a two-dimensional (2D) projection of such a beam's phase space, for example, f (x, x′). Another scanner might yield f (y, y′) or, using crossed slits, f (x, y). A small set of such 2D scans does not uniquely specify f (x, y, x′, y′). 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. We briefly summarize one method and describe progress in validating it, using simulations of the High Current Experiment at Lawrence Berkeley National Laboratory.

scholarly journals Operating Experience with a High Current Cs+1 Injector for Heavy Ion Fusion

1981 ◽  
Vol 28 (3) ◽  
pp. 3389-3391 ◽  
Author(s):  
W. Chupp ◽  
A. Faltens ◽  
E. Hartwig ◽  
E. Hoyer ◽  
D. Keefe ◽  
...  
Keyword(s):  
Operating Experience ◽  
Heavy Ion ◽  
High Current ◽  
Heavy Ion Fusion
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