Beam envelope, injection, and acceleration in a compact, high-current, strong-focused recirculating accelerator scheme. Technical report

Technical Report · Thu Dec 01 00:00:00 EST 1988

OSTI ID:6286388

Prakash, A

In order to meet the criterion of compactness in developing high-current, high-energy electron accelerators, it is advantageous to recirculate the electron beam through an accelerating module. Various such recirculating-accelerator concepts that use strong-focusing magnetic fields may be conveniently referred to as SFRA (Strong Focused Recirculating Accelerators). The strong-focusing field can be produced by external current-carrying stellarator or torsatron windings. SLIA, Stellatron, RIA and rebatron are examples of SFRA. High current electron beam transport in externally applied stellarator and longitudinal magnetic fields is analyzed. It is shown that a constant of motion exists for a matched beam of rotating elliptical cross section, with self-fields included. A differential equation for the beam envelope is derived and is shown to reduce to the familiar beam envelope equation for a beam of circular cross section when the stellarator field is turned off. A summary description of beam dynamics of acceleration in one SFRA, the rebatron, is given. Although a rebatron with major radius 100 cm and minor radius 10 cm can accelerate electrons to gamma about 65 with a fixed vertical (bending) magnetic field, the insensitivity to energy mismatch poses a problem for beam-trapping and injection. It is shown that a beam trapping scheme, in which a rapidly varying vertical magnetic field is applied before activating the rebatron acceleration gap, would work for a 10-kA beam of 1-cm radius injected near the wall of a rebatron of minor radius 16 cm.

• Research Organization: Army Armament Research and Development Command, Aberdeen Proving Ground, MD (USA). Ballistics Research Lab.
• OSTI ID: 6286388
• Report Number(s): AD-A-203224/1/XAB; BRL-TR-2956
• Country of Publication: United States
• Language: English

Related Subjects

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CYCLIC ACCELERATORS
BEAM OPTICS
ELECTRON BEAMS
FOCUSING
ACCELERATION
BEAM INJECTION
CROSS SECTIONS
DIFFERENTIAL EQUATIONS
DYNAMICS
EQUATIONS
MAGNETIC FIELDS
PROGRESS REPORT
STELLARATORS
ACCELERATORS
BEAMS
CLOSED PLASMA DEVICES
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LEPTON BEAMS
MECHANICS
PARTICLE BEAMS
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430200* - Particle Accelerators- Beam Dynamics
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