30 June 2004MICE VC1 MICE  functions Since last VC report: –New Mike Green configurations for decreased spacing between focus and matching coils of 400mm, 500mm, 600mm (old) –These require thinner (custom) gate valves for radiation shielding –Design for these being worked on by S. Yang in Oxford Ulisse Bravar has found the matching for these new solutions as well as matches for 240 MeV/c (not previously investigated)

30 June 2004MICE VC2 Bob Palmer 9/2003 `M. Green 600 mm’  larger -- presumably due to increased spacing matching – focus coils and smaller B Smaller momentum acceptance: off momentum muons might scrape beam aperture Different here BzBz  Reminder

30 June 2004MICE VC3 What is a  function ? Property of magnetic field of channel rms beam size related to  function and emittance  : Need  beam  radius of channel to keep losses small For 1% loss require  beam  radius of channel / 3 Example: Norm’d emittance  cm, r = 20 cm (say) require  140 cm

30 June 2004MICE VC4 Use analytic evolution of beta function – not ICOOL or G4Mice Shown previously to agree with ICOOL - but much faster Should check some cases with ICOOL eventually Look at Beta and 3 x rms beam size compared with aperture of channel for emittance = 0.6 cm Consider solutions in proposal of academic interest only! Have looked at SFOFO  = 42 cm solutions (‘tunes’) only for the 3 current Mike Green configurations There are at least 54 other configurations of Beta (7, 15 and 25 cm) times SFOFO / SEMIFLIP / NONFLIP times 400 mm / 500 mm / 600 mm times (decide !) 200 / 240 MeV/c to investigate.... (and stages IV and V....)

30 June 2004MICE VC5  200 MeV/c, M. Green configurations, 400, 500, 600mm 400 mm500 mm600 mm New Old Green = - 5% solid -10% dashed Black = On momentum Red = + 5% solid +10% dashed Beta always > 1.8 metres in 2nd RF for p = 1.1 x p tune Decreased spacing helps beta-stability ‘400mm’ not as stable as Palmer solution (not buildable?)

30 June 2004MICE VC6  240 MeV/c, M. Green configurations, 400, 500, 600mm 400 mm500 mm600 mm New 240 MeV/c looks ‘tidier’ Beta still rises in 2 nd RF – but less than at 200 MeV/c

30 June 2004MICE VC7 200 MeV/c  mm 200 MeV/c  mm 200 MeV/c  mm 3  Beam 200 MeV/c (and lower) for  = 0.6 cm Same colour code, Black outer line = aperture; 15 cm tracker Note: Exact shape may depend on initial phase -- to understand.... Assumes ‘good behaviour’.ps &.ppt don’t mix well! Some 3  clipping for +10% off-momentum muons; + / - 5% OK 400mm best in show

30 June 2004MICE VC8 240 MeV/c  mm 240 MeV/c  mm 240 MeV/c  mm 3  Beam 240 MeV/c  = 0.6 cm Field in detector solenoid kept at 4T No 3  clipping; 400mm best

30 June 2004MICE VC9 Summary 240 MeV/c looks more stable than 200 MeV/c (no surprise?) Reclaiming space helps – M. Green’s ‘400 mm’ configuration best Need to understand what a good criterion is –1/10,000 loss would require r/  > 4.3 (OTT ?) –1/1000 loss would require r/  > 3.7 –But note that U.B.’s study of real beam suggests only +/- 5% dp/p is useful (work in progress -- TBC) Look at other settings and Stages IV and V: –SFOFO / Semi-flip / Non-flip Work in progress....much to do