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Title: Centroid and Envelope Eynamics of Charged Particle Beams in an Oscillating Wobbler and External Focusing Lattice for Heavy Ion Fusion Applications

Abstract

Recent heavy ion fusion target studies show that it is possible to achieve ignition with direct drive and energy gain larger than 100 at 1MJ. To realize these advanced, high-gain schemes based on direct drive, it is necessary to develop a reliable beam smoothing technique to mitigate instabilities and facilitate uniform deposition on the target. The dynamics of the beam centroid can be explored as a possible beam smoothing technique to achieve a uniform illumination over a suitably chosen region of the target. The basic idea of this technique is to induce an oscillatory motion of the centroid for each transverse slice of the beam in such a way that the centroids of different slices strike different locations on the target. The centroid dynamics is controlled by a set of biased electrical plates called 'wobblers'. Using a model based on moments of the Vlasov-Maxwell equations, we show that the wobbler deflection force acts only on the centroid motion, and that the envelope dynamics are independent of the wobbler fields. If the conducting wall is far away from the beam, then the envelope dynamics and centroid dynamics are completely decoupled. This is a preferred situation for the beam wobbling technique, becausemore » the wobbler system can be designed to generate the desired centroid motion on the target without considering its effects on the envelope and emittance. A conceptual design of the wobbler system for a heavy ion fusion driver is briefly summarized.« less

Authors:
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1030418
Report Number(s):
PPPL-4641
TRN: US1200430
DOE Contract Number:  
DE-ACO2-09CH11466
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BOLTZMANN-VLASOV EQUATION; CHARGED PARTICLES; DEPOSITION; DESIGN; FOCUSING; HEAVY IONS; IGNITION; ILLUMINANCE; PLATES; TARGETS; Beams, Heavy Ion

Citation Formats

Ronald C. Davidson and B. Grant Logan. Centroid and Envelope Eynamics of Charged Particle Beams in an Oscillating Wobbler and External Focusing Lattice for Heavy Ion Fusion Applications. United States: N. p., 2011. Web. doi:10.2172/1030418.
Ronald C. Davidson and B. Grant Logan. Centroid and Envelope Eynamics of Charged Particle Beams in an Oscillating Wobbler and External Focusing Lattice for Heavy Ion Fusion Applications. United States. https://doi.org/10.2172/1030418
Ronald C. Davidson and B. Grant Logan. 2011. "Centroid and Envelope Eynamics of Charged Particle Beams in an Oscillating Wobbler and External Focusing Lattice for Heavy Ion Fusion Applications". United States. https://doi.org/10.2172/1030418. https://www.osti.gov/servlets/purl/1030418.
@article{osti_1030418,
title = {Centroid and Envelope Eynamics of Charged Particle Beams in an Oscillating Wobbler and External Focusing Lattice for Heavy Ion Fusion Applications},
author = {Ronald C. Davidson and B. Grant Logan},
abstractNote = {Recent heavy ion fusion target studies show that it is possible to achieve ignition with direct drive and energy gain larger than 100 at 1MJ. To realize these advanced, high-gain schemes based on direct drive, it is necessary to develop a reliable beam smoothing technique to mitigate instabilities and facilitate uniform deposition on the target. The dynamics of the beam centroid can be explored as a possible beam smoothing technique to achieve a uniform illumination over a suitably chosen region of the target. The basic idea of this technique is to induce an oscillatory motion of the centroid for each transverse slice of the beam in such a way that the centroids of different slices strike different locations on the target. The centroid dynamics is controlled by a set of biased electrical plates called 'wobblers'. Using a model based on moments of the Vlasov-Maxwell equations, we show that the wobbler deflection force acts only on the centroid motion, and that the envelope dynamics are independent of the wobbler fields. If the conducting wall is far away from the beam, then the envelope dynamics and centroid dynamics are completely decoupled. This is a preferred situation for the beam wobbling technique, because the wobbler system can be designed to generate the desired centroid motion on the target without considering its effects on the envelope and emittance. A conceptual design of the wobbler system for a heavy ion fusion driver is briefly summarized.},
doi = {10.2172/1030418},
url = {https://www.osti.gov/biblio/1030418}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jul 19 00:00:00 EDT 2011},
month = {Tue Jul 19 00:00:00 EDT 2011}
}