BBU gain measurements on the ITS 6-MeV, 4-kA linac

Author

Allison, Paul ; Moir, David C.

Author_Institution

Los Alamos Nat. Lab., NM, USA

Volume

1

fYear

1997

fDate

12-16 May 1997

Firstpage

1138

Abstract

The amplification of transverse beam motion by the ITS eight-cell linear induction accelerator (LIA) was measured with a 4-kA beam at frequencies between 710- and 950-MHz. The 3.75-MeV injector beam was deflected with amplitudes of ~1 mrad by an RF-driven tunable cavity 84 cm before the linac. The centroid-position waveforms from calibrated B-dot loops were recorded with 5-GS/s digitizers at the linac entrance, exit, and after a further free drift of 108 cm. The FFT amplitudes of the waveforms were used to compute the gains. The code LAMDA, an envelope and BBU model for the linac, was used to interpret the gain curves, using the transverse impedances of the cells as adjustable parameters. The results compare favorably with cell impedances previously measured with a two-wire TSD method

Keywords

accelerator RF systems; accelerator cavities; collective accelerators; high energy physics instrumentation computing; linear accelerators; particle beam diagnostics; particle beam injection; 3.75 MeV; 4 kA; 710 to 950 MHz; ITS linac; LAMDA code; RF-driven tunable cavity; beam-breakup gain measurements; calibrated B-dot loops; cell impedances; centroid-position waveforms; eight-cell linear induction accelerator; gain curves; injector beam deflection; linac; transverse beam motion amplification; transverse impedances; two-wire TSD method; Calibration; Frequency measurement; Gain measurement; Impedance measurement; Laboratories; Linear particle accelerator; Magnetic field measurement; Magnets; Motion measurement; Particle beams;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 1997. Proceedings of the 1997

Conference_Location

Vancouver, BC

Print_ISBN

0-7803-4376-X

Type

conf

DOI

10.1109/PAC.1997.749954

Filename

749954