Feed-forward compensation for transient beam loading of the 805 MHz debuncher for the Fermilab linac upgrade

Conference · Fri Sep 07 04:00:00 EDT 1990

OSTI ID:6489074

MacLachlan, J A; Mills, F E; Owens, T

The expected momentum spread from the 400 MeV upgrade of the Fermilab linac is {plus minus}0.19% growing to about {plus minus}0.25% in 63 m of beam transport to the booster synchrotron. The desired injection value is about {plus minus}0.05%. An 805 MHz (h=1) debuncher is located 47 m downstream of the linac to reduce the momentum spread and the differences in mean energy between bunches. The beam pulse to the booster will vary from about 2--15 {mu}s at average current of 30--50 mA depending on program need. During 15 {mu}s the beam excitation of the debuncher can reach 2.2 MV/m for a three-cell cavity. This gradient is comparable to, but 90{degree} out of phase with, the 3.85 MV/m required to minimize the momentum spread. We choose to use feed-forward compensation to control the cavity field for the entire beam pulse. We discuss some general features of transient beam loading as well as the design and detailed simulation of the compensation scheme.

• Research Organization: Fermi National Accelerator Lab., Batavia, IL (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC02-76CH03000
• OSTI ID: 6489074
• Report Number(s): FNAL/C-90/174; CONF-9009123--39; ON: DE91001544
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430200* -- Particle Accelerators-- Beam Dynamics
Field Calculations
& Ion Optics
430303 -- Particle Accelerators-- Experimental Facilities & Equipment
ACCELERATORS
BEAM BUNCHING
BEAM DYNAMICS
BEAM EMITTANCE
BEAM INJECTION
BEAM TRANSPORT
CYCLIC ACCELERATORS
FERMILAB ACCELERATOR
MODIFICATIONS
SYNCHROTRONS