scholarly journals New concept on the application of supersonic gas jets for space charge neutralized beam transport in an ICF reactor chamber

1997 ◽  
Vol 15 (2) ◽  
pp. 231-233
Author(s):  
P. Spiller ◽  
V. L. Varentsov
Keyword(s):  
Space Charge ◽  
Plasma Channel ◽  
Ballistic Transport ◽  
Supersonic Jet ◽  
Heavy Ion ◽  
Beam Transport ◽  
Channel Stability ◽  
High Current Discharge ◽  
Gas Expansion ◽  
Heavy Ion Fusion

One of the most crucial problems of a heavy ion fusion (HIF) driver is the transport of the beam from the final focusing system to the fusion target. The conventional focusing scheme is based on ballistic transport, assuming that all space charge effects can be kept sufficiently small. To achieve a space charge neutralized beam transport, other more sophisticated schemes like beam transport in a plasma channel have been suggested. Inspired by the results of the first experiments on the generation of adequate discharge-driven plasmas, we suggest applying a pulsed supersonic gas jet for the high-current discharge channel creation, thereby improving the plasma channel stability. The supersonic jet is produced by a gas expansion into the reactor chamber through a converging-diverging nozzle that has a hollow inner tube on its axis for both heavy ion and UV laser beam injection.

scholarly journals Transport of heavy-ion beams in a 1 m free-standing plasma channel

2006 ◽  
Vol 24 (1) ◽  
pp. 71-80 ◽  
Author(s):  
S. NEFF ◽  
R. KNOBLOCH ◽  
D.H.H. HOFFMANN ◽  
A. TAUSCHWITZ ◽  
S.S. YU
Keyword(s):  
Fusion Reactor ◽  
Ballistic Transport ◽  
Heavy Ion ◽  
Ion Beams ◽  
Beam Transport ◽  
Free Standing ◽  
Plasma Channels ◽  
Channel Transport ◽  
Stable Plasma ◽  
Heavy Ion Fusion

The transport of high-current heavy-ion beams in plasma channels is a promising option for the final transport in a heavy-ion fusion reactor, since it simplifies the construction of the reactor chamber significantly. Our experiments at the Gesellschaft für Schwerionenforschung demonstrate the creation of 1 m long stable plasma channels and the transport of heavy-ion beams. The article outlines the experimental setup used at GSI and reports the results of beam transport measurements using these long channels. The experiments demonstrate good beam transport properties of the channel, indicating that channel transport is a viable alternative to neutralized-ballistic transport.

Plasma lens focusing and plasma channel transport for heavy ion fusion

1996 ◽  
Vol 32-33 ◽  
pp. 493-502 ◽  
Author(s):  
A. Tauschwitz ◽  
S.S. Yu ◽  
S. Eylon ◽  
R.O. Bangerter ◽  
W. Leemans ◽  
...  
Keyword(s):  
Plasma Channel ◽  
Heavy Ion ◽  
Channel Transport ◽  
Heavy Ion Fusion

scholarly journals Simulations of longitudinal instabilities in ion induction linear accelerators

1992 ◽  
Vol 10 (3) ◽  
pp. 511-529 ◽  
Author(s):  
Stanley Humphries
Keyword(s):  
Space Charge ◽  
Transmission Lines ◽  
Axial Velocity ◽  
Cell Model ◽  
Heavy Ion ◽  
Velocity Spread ◽  
Continuous Systems ◽  
Linear Accelerators ◽  
Simulation Code ◽  
Heavy Ion Fusion

This article describes computer simulations of a longitudinal instability that affects induction linear accelerators for high-power ion beams. The instability is driven by axial bunching of ions when they interact with acceleration gaps connected to input transmission lines. The process is similar to the longitudinal resistive wall instability in continuous systems. Although bunching instabilities do not appear in existing induction linear accelerators for electrons, they may be important for proposed ion accelerators for heavy ion fusion. The simulation code is a particle-in-cell model that describes a drifting beam crossing discrete acceleration gaps with a self-consistent calculation of axial space charge forces. In present studies with periodic boundaries, the model predicts values for quantities such as the stabilizing axial velocity spread that are in good agreement with analytic theories. The simulations describe the nonlinear growth of the instability and its saturation with increased axial emittance. They show that an initially cold beam is subject to a severe disruption that drives the emittance well above the stabilized saturation levels. The simulation results confirm that axial space charge forces do not reduce axial beam bunching. In fact, space charge effects increase the axial velocity spread required for stability. With simple resistive driving circuits, the model predicts velocity spreads that are too high for heavy ion fusion applications. Several processes currently under study may mitigate this result, including advanced pulsed power switching methods, enhanced gap capacitance, and an energy spread impressed between individual beams of a multibeam transport system.

scholarly journals Experimental investigation of ion beam transport in laser initiated plasma channels

2002 ◽  
Vol 20 (4) ◽  
pp. 559-563 ◽  
Author(s):  
D. PENACHE ◽  
C. NIEMANN ◽  
A. TAUSCHWITZ ◽  
R. KNOBLOCH ◽  
S. NEFF ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heavy Ions ◽  
Plasma Channel ◽  
Ion Beam ◽  
Heavy Ion ◽  
High Current ◽  
Beam Transport ◽  
Electrode Gap ◽  
Discharge Gap ◽  
The Magnetic Field

The aim of the presented experiments is to study the transport of a heavy ion beam in a high-current plasma channel. The discharge is initiated in NH3 gas at pressures between 2 and 20 mbar by a line-tuned CO2 laser. A stable discharge over the entire electrode gap (0.5 m) was achieved for currents up to 60 kA. Concerning the ion beam transport, the magnetic field distribution inside the plasma channel has to be known. The ion-optical properties of the plasma channel have been investigated using different species of heavy ions (C, Ni, Au, U) with 11.4 MeV/u during six runs at the Gesellschaft für Schwerionenforschungs-UNILAC linear accelerator. The high magnetic field allowed the accomplishment of one complete betatron oscillation along the discharge channel. The results obtained up to now are very promising and suggest that, by scaling the discharge gap to longer distances, the beam transport over several meters is possible with negligible losses.

Intense-heavy-ion-beam transport through an insulator beam guide for heavy ion fusion

1999 ◽  
Author(s):  
Takashi Kikuchi ◽  
Shigeo Kawata ◽  
Shigeru Kato ◽  
Susumu Hanamori ◽  
Masaru Yazawa
Keyword(s):  
Ion Beam ◽  
Heavy Ion ◽  
Beam Transport ◽  
Heavy Ion Beam ◽  
Heavy Ion Fusion

Tests of prototype quadrupole magnets for heavy ion fusion beam transport

2003 ◽  
Vol 13 (2) ◽  
pp. 1508-1511
Author(s):  
C. Gung ◽  
J.V. Minervini ◽  
J.H. Schultz ◽  
R.B. Meinke ◽  
C.L. Goodzeit ◽  
...  
Keyword(s):  
Heavy Ion ◽  
Beam Transport ◽  
Heavy Ion Fusion

scholarly journals Experiments with space-charge-dominated beams for heavy ion fusion applications

2002 ◽  
Vol 20 (4) ◽  
pp. 599-602 ◽  
Author(s):  
P.G. O'SHEA ◽  
R.A. KISHEK ◽  
M. REISER ◽  
B. BEAUDOIN ◽  
S. BERNAL ◽  
...  
Keyword(s):  
Space Charge ◽  
Heavy Ion ◽  
Model System ◽  
Low Energy ◽  
Inertial Fusion ◽  
University Of Maryland ◽  
Strong Focusing ◽  
Fusion Applications ◽  
The University ◽  
Heavy Ion Fusion

A detailed understanding of the physics of space-charge-dominated beams is vital in the design of heavy ion inertial fusion (HIF) drivers. In that regard, low-energy, high-intensity electron beams provide an excellent model system. The University of Maryland Electron Ring (UMER), currently being installed, has been designed to study the physics of space-charge-dominated beams with extreme intensity in a strong focusing lattice with dispersion. At 10 keV and 100 mA, the beam from the UMER injector has a generalized perveance as much as 0.0015, corresponding to that of proposed HIF drivers. Though compact (11 m in circumference), UMER will be a very complex device by the time of its completion (expected 2003). We present an update on the construction as well as recent experimental results.

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