Beam spot size measurements A. Fisher & W. Kozanecki See details in PEP-II e-logbook, 25 Apr 06 day shift Single-beam & IP beam size measurements  scans at moderate currents (to minimize beam-beam effects) simultaneously measure beam sizes @ HER & LER SLM, interferometer & SXM both in collision and in single-beam mode with (almost?) the same lattices as characterized on 21/22 Apr 06 will then use R-matrices derived from MIA data of 21-22 Apr to estimate HER & LER IP beam sizes, using  measurements as a constraint Calibration of HER SLM scale using local closed-orbit bump

 scans Beam conditions Data files: PHYSICS5_DATA (FJD, MS, JT, GY) standard by-2, 1722 bunches I- / I+ = 535/230 mA (.31/.13 mA/b) 1 round of tune optimization in collision before beam-bean scans Data files: PHYSICS5_DATA [pep2.ip.witold.spr06]*25Apr [pep2.char.25apr06]

Beam currents & luminosity Stable collisions e- only e+ only current Lsp Hcurrent

 Stable collisions e+ only SLM X interf Y SXM X SXM Y

x-tilt & HER  Stable collisions e+ only SXM  Stable collisions e- only Stable collisions e- only HSLM X Hinterf Y

Beam size measurement summary Spot size data file: LUMSIZ_2B_25Apr HER dispersion: 21 Apr 06 LER collide/ e+ only HER collide/ e- only IP Ib [mA/bunch)] 0.31 / 0.41 0.13 / 0.13 - x (SLM) [mm] 1.75 / 1.60 1.335 / 1.360 y (interf) [mm] 0.23 / 0.24 0.207 / 0.204 1(M) (SXM) [mm] 0.410 / 0.406 2(m) (SXM) [mm] 0.238 / 0.236  (SXM) [deg] 9.5 / 8.6 x (major) [m] 169.4 y [m] 6.7 x (SLM) [mm] -892.1 1138 y (interf) [mm] 100.8 20.1 x (SXM) [mm] 328.5 y (SXM) [mm] 19.7

HER SLM calibration Two steps Data files: HSLM_XCALIB_2_25APR HSLM_YCALIB_1_25APR HER SLM calibration Two steps SLM response vs. knob: d centroid_x, y / d Knob_x, y x: 0.840 y: 0.850 (d SLM / d knob) knob calibration wrt BPMs using orbit fit x: 0.952 y: 0.982 (d OrbFit / d kknob) Overall: x (y) measured / true = 0.882 (0.867) Note that this vertical calibration applies to the HER SLM only, NOT to the corresponding interferometer

Spares

Bump closure & orbit fits at HER SLM for a 0.5mm bump

SLM/interf off-diagonal response X scan: Y centroid Y scan: X centroid X scan: Y size Y scan: X size

Dispersion at HER & LER SLM/SXM LER SXM HER SLM