Improved bunch spreader modules

Technical Report · Thu Jul 20 04:00:00 EDT 1989

DOI:https://doi.org/10.2172/5773307· OSTI ID:5773307

Ieiri, Takao

In order to raise the threshold beam current of instabilities in the fixed target run, it is required to increase the longitudinal emittance, and hence the bunch length. The bunch spreader used a noise generator through a sharp-cut ban pass filter (BPF) instead of a coherent signal. In that filter, the pass band frequency was near twice the synchrotron frequency 2f/sub s/. The bandwidth of the filter was fixed between 350Hz and 600Hz, though twice the synchrotron frequency changed from 500Hz to 300Hz after transition in Main Ring. The noise through the filter is applied to an RF amplitude modulator. In the Tevatron, where the synchrotron frequency f/sub s/ varies from 120Hz to 40Hz during acceleration, the noise is applied to a phase shifter at the frequency of f/sub s/. So, we need a tunable filter which tracks 2f/sub s/ in the Main Ring and f/sub s/ in the Tevatron. This note describes details of improved bunch spreader modules using a tunable filter used in both the Main Ring and the Tevatron. A brief description about this module along with a beam test done in the Main Ring is shown. 3 refs., 6 figs.

• Research Organization: Fermi National Accelerator Lab., Batavia, IL (USA)
• DOE Contract Number: AC02-76CH03000
• OSTI ID: 5773307
• Report Number(s): FNAL-TM-1608; ON: DE89015588
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430200* -- Particle Accelerators-- Beam Dynamics
Field Calculations
& Ion Optics
ACCELERATORS
BEAM BUNCHERS
BEAM BUNCHING
BEAM DYNAMICS
BEAM EMITTANCE
CYCLIC ACCELERATORS
ELECTRIC FILTERS
FERMILAB TEVATRON
FILTERS
MODIFICATIONS
SYNCHROTRONS