Stephen Brooks

1
Low-Frequency Phase Rotation

• The UKNF phase rotator evolved from the CERN
  design
• ?E reduction occurs in a single RF bucket
• The Rees design used 67.5MV of peak voltage at
  31.4MHz ? 18023MeV goal

2
Problem with Two Signs

• Negative muons are rotated backwards
• 61/09 longitudinal efficiency for /-

3
Solution (idea) for Two Signs
I. Mixed-sign drifted bunch from decay channel
II. Separate signs with on-peak RF
III. Drift further to get separation in time
IV. Put bunches on opposite sides of two
adjacent wave troughs, to get the reverse sign
separation and remaining phase rotation
simultaneously
4
Output for 31.4MHz Dual-Sign!
5
Further Optimisation

• Efficiency was 37/45 for plus/minus
• Less of each, but more in total
• Allowing variation of RF frequencies has produced
  efficiencies of 47/56

Getting more bunches higher frequency looking a
bit more like the Neuffer scheme?
6
Comments

• Note that while these efficiencies are comparable
  with Study 2a, the longitudinal phase space
  occupied is smaller
• Slightly smaller energy spread
• Many fewer bunches (but lower frequency)
• Bunch train well under 100ns long
• These schemes are longer and use more RF than the
  original (130m vs. 42m)

7
Comments

• Future work will be to match the output bunches
  with those accepted into the Rees cooling ring or
  similar
• These are preliminary results
• So apologies for lack of scales on graphs etc.