Betatrons with kiloampere beams

Conference · Mon Nov 01 00:00:00 EST 1982

OSTI ID:6533490

Peterson, J M

Although the magnetic-induction method of acceleration used in the betatron is inherently capable of accelerating intense particle beams to high energy, many beam-instability questions arise when beams in the kilo-ampere range are considered. The intense electromagnetic fields produced by the beam, and by the image currents and charges induced in the surrounding walls, can produce very disruptive effects. Several unstable modes of collective oscillation are possible; the suppression of any one of them usually involves energy spread for Landau damping and careful design of the electrical character of the vacuum chamber. The various design criteria are often mutually incompatible. Space-charge detuning can be severe unless large beam apertures and high-energy injection are used. In order to have an acceptably low degree of space-charge detuning in the acceleration of a 10-kilo-ampere electron beam, for example, an injection energy on the order of 50 MeV seems necessary, in which case the forces due to nearby wall images can have a larger effect than the internal forces of the beam. A method of image compensation was invented for reducing the net image forces; it serves also to decrease the longitudinal beam impedance and thus helps alleviate the longitudinal instability as well. In order to avoid the ion-electron collective instability a vacuum in the range of 10/sup -8/ torr is required for an acceleration time of 1 millisecond. A multi-ring betatron system using the 50-MeV Advanced Test Accelerator at LLNL as an injector was conceptually designed.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6533490
• Report Number(s): LBL-15206; CONF-821123-34; ON: DE83005857
• Resource Relation: Conference: 7. conference on the application of accelerators in research and industry, Denton, TX, USA, 8 Nov 1982; Other Information: Portions are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
BETATRONS
BEAM DYNAMICS
KILO AMP BEAM CURRENTS
BEAM OPTICS
ELECTRON BEAMS
INSTABILITY
LIMITING VALUES
SPACE CHARGE
TUNING
ACCELERATORS
BEAM CURRENTS
BEAMS
CURRENTS
CYCLIC ACCELERATORS
LEPTON BEAMS
PARTICLE BEAMS
430200* - Particle Accelerators- Beam Dynamics
Field Calculations
& Ion Optics