CESR Online | Elog Calendar | CESR Ops - Last 24hrs | Search CESR+Ops elog | Search old elog | Scoreboard CESR Ops entries for 2015-12-26 | CESR Ops entries for 2015-12-27 | Beamloss Data | Status Panels | CesrPlots | Plotf Dir CESR ERL demo CESR Ops CTA MS Instrumentation CHESS_MS CTA MS Log book Not logged in ELOG logo First entry, Ctrl-Home Previous entry, Ctrl-PgUp Next entry, Ctrl-PgDn Last entry, Ctrl-End List | Find | Login | Last day | Help Message ID: 2265 Entry time: 2015-12-13, 07:37, Sunday Author: Jeremy Perrin, David Rubin, Nate Rider, Suntao Wang, Stephen Poprocki Subject: Wakefield measurements Category: Other Instrument: Shift Key: 20151213_0800 0735 Plan for lattice tuneup: For first lattice (phase 0) loop machine (done), run orbit, phase corrections, then tuneup xbsm. Save this orbit and use as reference for the rest of this shift for each new lattice. Also when tuning to this orbit, use JSh's weights for xbsm orbit: set ref_orbit_x(0:88)=0 set ref_orbit_y(0:88)=0 set ref_orbit_y(7:8)=orbit_y set ref_orbit_y(33:35)=orbit_y orbit_x_wgt(89:99)=1.e8 orbit_y_wgt(89:99)=1.e8 orbit_y_wgt(7:8)=1.e8 orbit_y_wgt(33:35)=1.e8 orbit_y_wgt(43)=1.e8 hw=9.30E-08 vw=1.e-7 orbit_y_wgt(42:44)=1.e8 For each subsequent lattice (and the first) do additional tuneup before using. In particular do phase, coupling, dispersion corrections, tuneup orbit through scrapers, (test tune knobs?) The reference 'golden' xbsm orbit for the xbsm is 1079176. Saveset with ok orbit for xbsm is 149452 Corrected phase save csr 149453 update route Phase measurement 23071 orbit 1079778 Scrapers both in, use orbit 1079778 as reference Scrapers both in completely, readbacks are top 4.22mm, bottom 2.62mm. When we come back to 'scrapers in' conditions these numbers should be used. Orbit bump through scrapers, took orbit, bumped orbit is 1079780 Bump starts at 235cu = nominal center. Very poor lifetime at 3400cu on bump, falls out at 3600. Very poor lifetime at -1605cu on bump, falls out at -1965 Center should be about +800cu. Set bump to +800, take orbit 1079781. Some bumping to center in xbsm, take orbit 1079782. Save csr 149454 Attempt to center in undulator using old bumps Take orbits 1079783(zero bump) 1079784(100cu bump) Closed bump, update coefficients, save biggrp, update route Very poor lifetime at 109cu, beam falls out at 139cu. Very poor lifetime at -181cu, beam falls out at -201cu Center at -31cu. This is OK compared to earlier. Therefore, our reference orbit will be 1079782. ---------------------- Take both scrapers out for final tuneup. Final tuneup for phase +0 lattice: first phase and coupling. Corrected, save csr 149456 BPMs to fixed gain mode for final phase+eta tuning Looks good, save csr 149457 Ready to take data with this lattice. Zero current tunes are about 221kHz horizontal and 242.6kHz vertical. ------------------------- Data set 1 : Phase+0 lattice, both scrapers out, vertical tune nominally centered. Tunes at 3.70mA: H=221.2 V=240.0 Tunes at 4.00mA: H=221.2 V=239.6 Datataking start at 10:58AM Beam decay file# 18A Initial xbsm rd# 57309 Final xbsm rd# 57596 Tbts at 4mA 20348-49 Tbts at 3mA 20350-51 Tbts at 2mA 20352-53 Tbts at 1mA 20354-55 Phase measurement at low current (0.70mA): 23076 Vertical beam size fluctuates wildly as current decreases. Changing the xbsm analyzer from automatic to manual does not help. ------------------------- Data set 2 : Phase+0 lattice, both scrapers out, vertical tune nominally centered, but only fill to 2mA to start. This should test if the effect is current-dependent or a time buildup. Tunes at 2.00mA: H= V= Datataking start at 11:59AM Beam decay file# 18B Initial xbsm rd# 57598 Final xbsm rd# 57753 Tbts at 2mA 20356-57 Result: current-dependent, not time buildup. We realized that the vertical tune is probably crossing a synchrobetatron resonance. Set synchrotron tune to 23.0 kHz, Save set crf 149459 voltages 1.20 1.41 1.23 1.26. Updated route with this crf set. ------------------------- Data set 3 : Phase+0 lattice, both scrapers out, vertical tune nominally centered, synch tune properly set Tunes at 4.00mA: H=221.3 V=239.7 S=23.0 Datataking start at 12:40PM Beam decay file#18C Initial xbsm rd# 57754 Final xbsm rd# 57940 Tbts at 4mA 20358-59 Tbts at 3mA 20360-61 Tbts at 2mA 20362-63 Tbts at 1.15mA 20364-65 Phase measurement at low current (1.0mA): 23077 Things look much less bizarre this time. ------------------------- Data set 4: Phase+0 lattice, both scrapers in, vertical tune nominally centered Couldn't fill to 4mA due to scrapers Tunes at 3.47mA: H=221.25 V=238.9 S=23.0 Datataking start at 1:25PM Beam decay file# 18D Initial xbsm rd# 57943 Final xbsm rd# 58073 Tbts at 3.2mA 20366-67 Tbts at 2.2mA 20368-69 Tbts at 1.4mA 20370-71 Phase measurement at low current (1.0mA): 23078 Vertical size is very similar to data set 3. This is expected. We are probably well-centered in the scrapers. ------------------------- Data set 5 : Phase+0 lattice, scrapers top in bottom out, vertical tune nominally centered Tunes at 3.4 mA: H=221.3 V=239.65 S=22.9 Datataking start at 1:58PM Beam decay file#18E Initial xbsm rd# 58075 Final xbsm rd# 58217 Tbts at 3.43mA 20372-73 Tbts at 2.2mA 20374-75 Tbts at 1.3mA 20376-77 Phase measurement at low current (1mA): 23079 ------------------------- 2:20PM Preparing phase -18 lattice. Switched route, updated rf set magnet loop take o:1079799, corrected to 1079782. Still have light on xbsm. Set tunes to 221.0kHz and 242.6kHz One round of phase and coupling corrections Switched back to fixed gain mode for dispersion corrections Dispersion looks ok save csr 149460 Vertical beam size is bad (100 microns) Change horizontal tune to 225 kHz, fixes the problem (29 microns). Figure this out later. Save csr 149462 ------------------------- Data set 6: Phase-18 lattice, scrapers both out, vertical tune nominally centered, horizontal tune +4kHz Tunes at 4.00mA: H= 224.85 V=241.1 S=23.0 Datataking start at 3:07PM Beam decay file#18F Initial xbsm rd# 58225 Final xbsm rd# 58382 Tbts at 3.9mA 20378-79 Tbts at 2.8mA 20380-81 Tbts at 2mA 20382-83 Tbts at 1.1mA 20384-85 Phase measurement at low current (0.95mA): 23084 018C_018D_018E.png ------------------------- Data set 7: Phase-18 lattice, scrapers top in bottom out, vertical tune nominally centered, horizontal tune +4kHz Tunes at 3.9mA: H=224.9 V=240.0 S=23.0 Datataking start at 3:35PM Beam decay file# 190 Initial xbsm rd# 58383 Final xbsm rd# 58533 Tbts at 3.85mA 20386-87 Tbts at 2.1mA 20388-89 Tbts at 1.2mA 20390-91 Phase measurement at low current (1.0mA): 23085 ------------------------- Took tbt 20392-93 accidentally between runs Probably some data (191) here One scraper had popped out, making asymmetry. There is a little of this data at the beginning of 191. ------------------------- Data set 8: Phase-18 lattice, scrapers both in, vertical tune nominally centered, horizontal tune +4kHz Missed tunes Datataking start at 4:02PM Beam decay file# 191 Initial xbsm rd# 58537 Final xbsm rd# 58600 Tbts at 3.15mA 20394-95 Tbts at 2.0mA 20396-97 Tbts at 1.3mA 20398-99 Phase measurement at low current (1.05mA): 23086 018F_0190_0191.png Attachment 3: std_00165331.gif 10 kB Uploaded 2015-12-16, 11:50, Wednesday | Hide | Hide all std_00165331.gif Attachment 4: std_00165330.gif 9 kB Uploaded 2015-12-16, 11:51, Wednesday | Hide | Hide all std_00165330.gif CESR Online | Elog Calendar | CESR Ops - Last 24hrs | Search CESR+Ops elog | Search old elog | Scoreboard CESR Ops entries for 2015-12-26 | CESR Ops entries for 2015-12-27 | Beamloss Data | Status Panels | CesrPlots | Plotf Dir