Drift Compression and Final Focus for Intense Heavy Ion Beams with Non-periodic, Time-dependent Lattice

Qin, Hong ; Davidson, Ronald C. ; Barnard, John J. ; Lee, Edward P.

Princeton University. Plasma Physics Laboratory.

关键词: Acceleration;    Compression;    Space Charge Inertial Confinement Fusion;    70 Plasma Physics And Fusion Technology;    Quadrupoles;   

DOI  :  10.2172/836937
RP-ID  :  PPPL-4054
RP-ID  :  AC02-76CH03073
RP-ID  :  836937

美国|英语

来源: UNT Digital Library

【 摘 要 】

In the currently envisioned configurations for heavy ion fusion, it is necessary to longitudinally compress the beam bunches by a large factor after the acceleration phase. Because the space-charge force increases as the beam is compressed, the beam size in the transverse direction will increase in a periodic quadrupole lattice. If an active control of the beam size is desired, a larger focusing force is needed to confine the beam in the transverse direction, and a non-periodic quadrupole lattice along the beam path is necessary. In this paper, we describe the design of such a focusing lattice using the transverse envelope equations. A drift compression and final focus lattice should focus the entire beam pulse onto the same focal spot on the target. This is difficult with a fixed lattice, because different slices of the beam may have different perveance and emittance. Four time-dependent magnets are introduced in the upstream of drift compression to focus the entire pulse onto the sam e focal spot. Drift compression and final focusing schemes are developed for a typical heavy ion fusion driver and for the Integrated Beam Experiment (IBX) being designed by the Heavy Ion Fusion Virtual National Laboratory.