2/07/2014 EMITTANCE MEASUREMENTS MTA BEAMLINE

PERFORMANCE All stable optics tunes work 4 very different operations have been installed Experimental tune 180, 90, and 120  phase advance across emittance straight Two very different 90  tunes Provide consistent results MW4-6 All stable optics calculations without tuning Few pulses/very minor steering for exact centering Very low loss operation 0.3 mr/hr measured at emittance absorber Example 90  phase advance tune

EMITTANCE MEASUREMENT QUICK AND DIRTY METHOD Dispersion suppression across straight Phase advance MW4 – MW6 approaches 180  ~reflection of profiles Double parameter search of UQ08/UQ09 Location of minimum spot size Actual waist is a few centimeters upstream Introduces insignificant error Divergence is the most difficult parameter to measure ( , r 12, r 34 ) At 180 , f~=L,  =  x (or y)/L    x MW5 (or y)   Surprisingly accurate L Location of MW5  0, α 0,  0  1, α 1,  1  2, α 2,  2 Location of MW4

180  TUNE RESULTS PRELIMINAR MW4 – MW6 scaled to pitches (poor man scaling  x (full)  12 mm-mr tails increase across straight  y (full)  10 mm-mr Distinctly nonGaussian rms ~ 3 mm-mr With 55  of total horizontal bend in horz difficult to cancel D’ completely Observe dispersion increasing across straight and creating tails Horz MW4- MW6

MOMENTUM SPREAD MEASURE MW2 has a dispersion ~7m (2mm pitch) Appears to be a complicated profile – appears to be real Have to take the entire linac pulse into MTA beamline Artifacts from the first 2  sec before feedback circuits correct dp/p appears to be in the range of % from all high- dispersion locations

ANALYSIS AND FUTURE MEASUREMENTS Last call for beam 2/3/2014 Crane installation underway Unclear when we can run beam in near future Analyze 180/90 profiles Initial phase space tumbling Some evidence of nonelliptical phase space Need more phase advance data for tomography Chase all dipoles by 0.5-2% in strength Equivalent to dp/p shift measure dispersion x’ x x tumbling