Depolarizing 'beat' resonances in the Brookhaven AGS

Conference · Tue Oct 01 04:00:00 EDT 1985 · IEEE Trans. Nucl. Sci.; (United States)

OSTI ID:6399984

Terwilliger, K M; Courant, E D; Krisch, A D; Ratner, L D

While accelerating polarized protons in the Brookhaven AGS we found a variant of the standard imperfection and intrinsic depolarizing resonances which has some of the properties of both types. Imperfection resonances occur at G..gamma.. = k, when the number of spin precessions per revolution, G gamma, equals a harmonic of the depolarizing field, k. Intrinsic resonances occur at G..gamma.. = nP + or - ..nu.. /SUB Z/ , when the AGS gradient periodicities, nP, modulate free vertical betatron oscillations to create the sum and difference frequencies. The variant resonance is a beat between nP and an imperfection driven betatron oscillation of periodicity k'. These occur at G..gamma.. = nP + or - k', and are strongest when the driven betatron oscillation is largest. The effect was most dramatic at the strong G..gamma.. = 27 resonance. Since ..nu.. /SUB Z/ = 8.8 for the AGS, and there is a major nP = 36 AGS periodicity, a strong beat resonance should exist at G gamma = 36-9 = 27. Applying a 27 /SUP th/ harmonic correction directly was unsuccessful, but a 9 /SUP th/ harmonic correction removed the depolarization.

• Research Organization: University of Michigan, Ann Arbor, Michigan
• OSTI ID: 6399984
• Report Number(s): CONF-850504-
• Conference Information: Journal Name: IEEE Trans. Nucl. Sci.; (United States) Journal Volume: NS-32:5
• 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 DYNAMICS
BEAMS
BETATRON OSCILLATIONS
BROOKHAVEN AGS
CYCLIC ACCELERATORS
DEPOLARIZATION
NUCLEON BEAMS
ORIENTATION
OSCILLATIONS
PARTICLE BEAMS
POLARIZED BEAMS
PROTON BEAMS
RESONANCE
SPIN ORIENTATION
SYNCHROTRONS