Bunch coalescing in the main ring to form intense proton and antiproton bunches without RF counterphasing
Both the proton and antiproton bunches which will collide in the Tevatron have longitudinal emittance greater than can be accelerated by the main ring from 8 GeV without large loss and emittance growth. We have previously described the technique of combining several smaller bunches at the Tevatron injection energy with little increase in the total emittance and negligible loss. This technique requires adiabatic debunching of several adjacent 53 MHz bunches by smooth reduction of the RF voltage from approx. 1 MV to approx. 100 V. The very low voltage is extremely difficult to attain with a high-Q system designed for megavolt accelerating potential. The counterphasing technique of voltage reduction which we have used in main ring experiments and proposed for the TeV I project is to divide the accelerating cavities into two closely matched groups and to smoothly shift the relative phase of the drive to the two groups by 180 degrees. When the net voltage has been reduced by this means to the lowest practical level, about 10 kV, the final voltage reduction may be performed by turning off the high-Q system and using a low-Q cavity. The voltage induced on the undriven gaps of the high-Q system is low enough not to be a major problem because the total intensity is low. However, the effects are not negligible, and dynamic beam loading compensation is required. This memo proposes that the process described above be simplified somewhat by replacing the counterphasing voltage reduction with a zero-voltage spreading of the bunches for several milliseconds followed by a few hundred microseconds of rotation to minimum energy spread in buckets produced at high voltage.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- DOE Contract Number:
- AC02-76CH03000
- OSTI ID:
- 6557129
- Report Number(s):
- FNAL-TM-1280; ON: DE85001364
- Resource Relation:
- Other Information: Portions are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
TEVATRON
BEAM BUNCHING
ANTIPROTON BEAMS
BEAM EMITTANCE
PROTON BEAMS
THEORETICAL DATA
ACCELERATORS
ANTINUCLEON BEAMS
ANTIPARTICLE BEAMS
BEAM DYNAMICS
BEAMS
CYCLIC ACCELERATORS
DATA
INFORMATION
NUCLEON BEAMS
NUMERICAL DATA
PARTICLE BEAMS
SYNCHROTRONS
430200* - Particle Accelerators- Beam Dynamics
Field Calculations
& Ion Optics