Stephen Brooks Scoping Study meeting, July 2006 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  180±23MeV goal

Stephen Brooks Scoping Study meeting, July 2006 Problem with Two Signs Negative muons are rotated backwards: 61/09% longitudinal efficiency for +/-

Stephen Brooks Scoping Study meeting, July 2006 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

Stephen Brooks Scoping Study meeting, July 2006 Output for 31.4MHz Dual-Sign!

Stephen Brooks Scoping Study meeting, July 2006 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?

Stephen Brooks Scoping Study meeting, July 2006 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)

Stephen Brooks Scoping Study meeting, July 2006 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.