Operation of PEP longitudinal feedback system

Conference · Sun Mar 01 04:00:00 EST 1981

OSTI ID:6505671

Allen, M A; Karvonen, L G; McConnell, R A; Schwarz, H

In order to suppress longitudinal coupled-bunch oscillations which might limit the capabilities of PEP, the 18 GeV e/sup +/e/sup -/ storage ring at SLAC, a longitudinal feedback system is utilized. A frequency domain feedback system was chosen with the frequency spectrum of the stored beam being sampled close to a symmetry point in the ring where the feedback cavity itself is also located. The symmetry point chosen is symmetry point 5 which lies half-way between interaction regions 4 and 6. The system has been installed in PEP and is now operational. However, at stored currents up to the maximum stored in PEP to date at 14.5 GeV (approximately 40 mA in 6 bunches), the ring has been stable to all modes of longitudinal coupled-bunch oscillations both barycentric and the other fundamental modes. By deliberately detuning the main accelerating cavities, small multibunch oscillations can be introduced which, in turn, can be damped by the feedback system. Under optimized beam conditions the feedback system could be adjusted to positive feedback and excite oscillations with relatively small power to the feedback cavity. This will be described along with other details of the system.

• Research Organization: Stanford Linear Accelerator Center, CA (USA)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 6505671
• Report Number(s): SLAC-PUB-2670; CONF-810314-155; PEP-NOTE-351
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430200* -- Particle Accelerators-- Beam Dynamics
Field Calculations
& Ion Optics
BEAM BUNCHING
BEAM DYNAMICS
BEAM MONITORS
BEAMS
ELECTRON BEAMS
ENERGY RANGE
FEEDBACK
GEV RANGE
GEV RANGE 10-100
LEPTON BEAMS
MEASURING INSTRUMENTS
MONITORS
PARTICLE BEAMS
PEP STORAGE RINGS
PERFORMANCE
PHASE STABILITY
POSITRON BEAMS
STABILITY
STORAGE RINGS