scholarly journals Integrated experiments for heavy ion fusion

2003 ◽  
Vol 21 (4) ◽  
pp. 553-560 ◽  
Author(s):  
J.J. BARNARD ◽  
L.E. AHLE ◽  
F.M. BIENIOSEK ◽  
C.M. CELATA ◽  
R.C. DAVIDSON ◽  
...  

We describe the next set of experiments proposed in the U.S. Heavy Ion Fusion Virtual National Laboratory, the so-called Integrated Beam Experiment (IBX). The purpose of IBX is to investigate in an integrated manner the processes and manipulations necessary for a heavy ion fusion induction accelerator. The IBX experiment will demonstrate injection, acceleration, compression, bending, and final focus of a heavy ion beam at significant line charge density. Preliminary conceptual designs are presented and issues and trade-offs are discussed. Plans are also described for the step after IBX, the Integrated Research Experiment (IRE), which will carry out significant target experiments.

2002 ◽  
Vol 20 (3) ◽  
pp. 377-384 ◽  
Author(s):  
R.C. DAVIDSON ◽  
I.D. KAGANOVICH ◽  
W.W. LEE ◽  
H. QIN ◽  
E.A. STARTSEV ◽  
...  

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.


Author(s):  
Charles W. Allen ◽  
Robert C. Birtcher

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.


2002 ◽  
Vol 20 (3) ◽  
pp. 435-440 ◽  
Author(s):  
P.A. SEIDL ◽  
D. BACA ◽  
F.M. BIENIOSEK ◽  
A. FALTENS ◽  
S.M. LUND ◽  
...  

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.


Author(s):  
A. Friedman ◽  
J. Barnard ◽  
D. Cable ◽  
D.A. Callahan ◽  
F.J. Deadrick ◽  
...  

Author(s):  
J.J. Barnard ◽  
R.O. Bangerter ◽  
A. Faltens ◽  
T.J. Fessenden ◽  
A. Friedman ◽  
...  

2006 ◽  
Vol 24 (3) ◽  
pp. 359-369 ◽  
Author(s):  
TETSUO SOMEYA ◽  
KENTAROU MIYAZAWA ◽  
TAKASHI KIKUCHI ◽  
SHIGEO KAWATA

In order to realize an effective implosion, the beam illumination non-uniformity and implosion non-uniformity must be suppressed to less than a few percent. In this paper, a direct-indirect mixture implosion mode is proposed and discussed in heavy ion beam (HIB) inertial confinement fusion (HIF) in order to release sufficient fusion energy in a robust manner. On the other hand, the HIB illumination non-uniformity depends strongly on a target displacement (dz) in a reactor. In a direct-driven implosion mode dz of ∼20 μm was tolerance and in an indirect-implosion mode dz of ∼100 μm was allowable. In the direct-indirect mixture mode target, a low-density foam layer is inserted, and radiation is confined in the foam layer. In the foam layer the radiation transport is expected in the lateral direction for the HIB illumination non-uniformity smoothing. Two-dimensional implosion simulations are performed and show that the HIB illumination non-uniformity is well smoothed. The simulation results present that a large pellet displacement of ∼300 μm is tolerable in order to obtain sufficient fusion energy in HIF.


1993 ◽  
Vol 106 (11) ◽  
pp. 1593-1603
Author(s):  
L. L. Reginato ◽  

2002 ◽  
Vol 20 (3) ◽  
pp. 369-375 ◽  
Author(s):  
B.G. LOGAN ◽  
C.M. CELATA ◽  
J.W. KWAN ◽  
E.P. LEE ◽  
M. LEITNER ◽  
...  

Significant experimental and theoretical progress has been made in the U.S. heavy ion fusion program on high-current sources, transport, and focusing. Currents over 200 mA have been transported through a matching section and 10 half-lattice periods with electric quadrupoles. An experiment shows control of high-beam current with an aperture, while avoiding secondary electrons. New theory and simulations of the neutralization of intense beam space charge with plasma in various focusing chamber configurations predict that near-emittance-limited beam focal spot sizes can be obtained even with beam perveance (ratio of beam space potential to ion energy) >10× higher than in earlier HIF focusing experiments. Progress in a new focusing experiment with plasma neutralization up to 10−3 perveance, and designs for a next-step experiment to study beam brightness evolution from source to target are described.


1999 ◽  
Author(s):  
Takashi Kikuchi ◽  
Shigeo Kawata ◽  
Shigeru Kato ◽  
Susumu Hanamori ◽  
Masaru Yazawa

Author(s):  
R. C. Birtcher ◽  
L. M. Wang ◽  
C. W. Allen ◽  
R. C. Ewing

We present here results of in situ TEM diffraction observations of the response of U3Si and U3Si2 when subjected to 1 MeV electron irradiation or to 1.5 MeV Kr ion irradiation, and observations of damage occuring in natural zirconolite. High energy electron irradiation or energetic heavy ion irradiation were performed in situ at the HVEM-Tandem User Facility at Argonne National Laboratory. In this Facility, a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter have been interfaced to a 1.2 MeV AEI high voltage electron microscope. This allows a wide variety of in situ experiments to be performed with simultaneous ion irradiation and conventional transmission electron microscopy. During the electron irradiation, the electron beam was focused to a diameter of about 2 μ.m at the specimen thin area. The ion beam was approximately 2 mm in diameter and was uniform over the entire specimen. With the specimen mounted in a heating holder, the temperature increase indicated by the furnace thermocouple during the ion irradiation was typically 8 °K.


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