PEP-II Operation and Machine Development U. Wienands PEP-II Run Coordinator for the PEP-II Team
Outline of Talk PEP Run 4 Plan & Progress Parameters, Run statistics Machine Development How we run the machine program Examples of MD Conclusion Run 5 Outlook
PEP-II Parameters Design Achieved (delivery) Energies e / e+ (GeV) 8.973 3.119 Currents e / e+ (A) Single beam currents (A) 0.75 2.14 1.55 1.2 2.40 (2.45) 2.10 Number of bunches 1658 1600 Bunch currents e / e+ (ma) 0.45 1.29 1.24 2.09 Bunch spacing (m) 1.26 1.26 IP spot size σ * x / σ * y (µm) 155 4.7 147 5 Luminosity ( 10 33 /cm 2 /sec) 3.0 9.21 Tune shift horiz. e / e+ 0.03 0.03 0.059 0.09 Tune shift vert. e / e+ 0.03 0.03 0.031 0.07 Integrated lumi. / 3 shifts (pb 1 ) 135 710 Integrated lumi. / week (pb 1 ) 785 4295 Integrated lumi. / 7 days (pb 1 ) 785 4260 Integrated lumi. / month (fb 1 ) 3.3 16.02 Beam crossing angle 0 (head-on) 0 (head-on)
The Director s Challenges Director s s Challenge I: To deliver 100/fb to BaBar during Run 4 Sept. 9, 03 until July 31, 04; 2wk winter break Previous performance for a similar period: 50/fb (Run 3 pro-rated) Projected total delivery since beginning 253/fb Director s s Challenge II: To exceed 10 34 cm -2 s -1 and to exceed 850/fb for a day.
Run 4 Delivered Luminosity Actual delivery (>90/fb now) The Director s Challenge >100/fb delivered in Run 4
Typical (best) Day of PEP Running
PEP-II Run Time Dist. FY 04 M. Stanek Pre-trickle LER-trickle Double-trickle
Managing the Running Program The Run Coordinator is responsible for detailed planning of the PEP program The Program Deputy keeps the program on track (PEP & other) An Engineer Operator In Charge directs the operators on shift Typically 3 operators+eoic+pep acc. phys./shift Briefing every morning at 8:00 Followed by meeting PEP/BaBar Mgt. Followed by the Maintenance Meeting Acc. Plans mtg 1/week Acc. Plans mtg 1/week Integration with other activities
Communication with BaBar Daily Morning meeting (PEP RC) Weekly coordination meeting (BaBar TC) Review machine performance Review backgrounds Review trip rates Background meeting (WK) Background meeting (WK) Understanding of current issues Simulations for present & future IR configuration Long-term projection & mitigation
Meeting our Luminosity Goals Reliability of hardware 95% availability (PEP only) for Run 4 88% if injector is included. Delivering the Goods Peak luminosity 9.21 10 33, 3 times design (3 10 33 ) Average luminosity => Trickle Charge (Continuous injection) Prevent beam aborts Background aborts by BaBar, Rf, beam instab.
Machine Development MD is managed in a bi-weekly meeting (Mo-Th) Review state of the machine Review detailed MD plans, analysis of previous MD Put together MD teams & recovery team On average, 1 MD shift/week (+ recovery) Machine Characterization every 2 32 3 wks Ph.-advance,, MIA, sometimes coupling, chrom., Rolling 2-month plan, but maintain flexibility Standby MD items in case we cannot deliver only one ring avail., injector or detector problem,
MD Schedule June 2004 July 2004 M. Sullivan Also keep track of actual happenings on this schedule
Example: Plan for Xangle MD MD Preparation & planning is an involved process with attention to detail (2 pages from a 7-page MD plan, for a 1-shift MD)
Setting MD Directions We follow a few well defined goals: Meet or exceed the plan (104/fb for Run 4) Meet or exceed the Director s Challenge II L > 10 34 cm -2 s -1, 850/pb/diem Prepare for next Run s success, e.g.: characterize thermal behaviour of critical comp. Lower ß y *, shorten bunches, wiggler operation Take data critical for upgrades, e.g.: Understand effect of crossing angle Understand scaling of backgrounds
MD Studies Run 4 Dedicated time (bold: resulted in new setting of machine, new hw/sw) Trickle Charge LER Lower ß y * LER & HER Steer the HER Crossing-angle effect on Lumi Vacuum-comp. heating vs V rf Bunch-length parameterization New llrf module commissioning ORM, MIA data taking LGD Woofer commissioning Parasitic or opportunistic Trickle Charge HER Lower ß x * LER Steer the LER Damping-partition variation Background parametrization Grow-damp measurements HER Beam-abort gap reduction Machine characterization Klystron linearizer test LER solenoid effect on Lumi Effect of bunch patterns Raise Vrf in the HER, LER Bunch length measurements HOMs in vacuum components Rf working point explorations Llrf temperature drift investig. LER energy aperture LER Octupole effects Injection-kicker matching Beam-size, background variation Online leak checking IP knob calibration Orbit-feedback development C/S software maintenance
Trickle-Charge LER Large MD Items Trickle Charge HER Steer HER 1 test, 1 impl. MD 2 test, 1 impl. MD 1 impl. 3-shift MD Lower HER ßy* 1 test, 2 impl. MD Lower LER ßy* 1 test, 1 impl. MD Lower LER ßx* 1 test/impl. MD
PEP Run 4 MD List PEP MD List updated 15-Jun-04 Date MD Result 18-Sep-03 Characterization, ORM, MIA, IP apertures, Lumi scan data taken 29-Sep-03 HER BBA, Rf processing 10 BPM offsets 30-Sep-03 HER beta beat, MIA, Rf processing Knob works, but ßx* goes up 7-Oct-03 LER Trickle test Struggle with background 20-Oct-03 RF tuning, Characterization, Coupling 21-Oct-03 Coupling 23-Oct-03 HER Rf 7-stn. running, LER knobs 7-stn. running commissioned 28-Oct-03 HER rf 4-1, LER BBA, Characterization 4 BPM offsets, 4-1 not yet ready 30-Oct-03 by-2 pattern left in! 4 BPM offsets, ßx beat knob works but 4-Nov-03 LER BBA, HER ßx-beat knob test, HER rf wrong sign, calibration 13-Nov-04 LER trickle test, HER TFB 0.5/fb for BaBar in tricklemode Barry here:better procedure & tuning, 20-Nov-03 HER TFB tuning, LER BBA several LER BPM ofsets 2-Dec-03 LER trickle forever, HER injection, BPM upgrades SUCCESS! LER TRICKLES! 9-Dec-03 8-1, 12-1 klystron magnet tuning, LER BBA 8-1 klys. better, 12-1 not by much Lum scales as expected; ORM data taken, 11-Dec-03 Lumi vs bunch#, HER, LER ORM, HER ßx* knnob ßx* knob? 16-Dec-03 HER ßy* knob test, LER LGDW test knobs work as expected. 1st test LGDW 23-Dec-03 Last shift: push currents, lumi 7.20E+33 7-Jan-04 Turn-on 4-1, HER 8-station running
PEP Run 4 MD List (cont d) 8-Jan-04 HER steering 13-Jan-04 HER ßy*, Characterization 15-Jan-04 HER grow-damp (Long.), LER BBA, IP knobs 27-Jan-04 Background characterization 1-Feb-04 HER transverse grow-damps 3-Feb-04 LER ßy* knob test, HER ORM 5-Feb-04 HER trickle test 10-Feb-04 LER steering, HER ßxbeat test, pilolt gate 24-Feb-04 HER LGDW test, LER pilot timing 2-Mar-04 HER trickle test 11-Mar-04 Double trickle test & operation 16-Mar-04 Crossing Angle I 25-Mar-04 Crossing Angle II 4-May-04 ßy* reduction in both rings 6-May-04 LGD Woofer install, LER 4-5 rfp 11-May-04 Crossing angle III 18-May-04 HER lfb amps, LER 4-3 klys tuning 25-May-04 Vary HER damping partition, charact. 8-Jun-04 Heating vs bunch length 10-Jun-04 HER ORM data, LER ßx* knob test HER steered, new orbit ref. ßy* left in more LER BPM offsets, IP knobs calibrated needed for BaBar Roadmap Committee gain margins, system tuning (ok) SIMPLE & JLT knob, both work, sort-of, ORM data taken avg. trickle noise ok, bad fliers LER backed out due to ßx beat, HER ßx beat knob lifetime issue factor 2 in damping, fix FIR. Pilots difficult Fliers gone! Lumi break-even Success! We are double trickling! Lum vs Xangle, low & high I dto., fix tunes -0.75 mm, LER/-1.25 mm, HER Success! LGD Woofer in. 4-5 lost config... difficult recovery lfb amps fixed, new fans; 4-3 klys somewhat better Prediction of beam sizes verified. data taken ßx* knob good, left in. ORM data taken
Achievements this Run Trickle Charge operational for both rings Lowered ß y * to 10.5 mm in both rings Lowered ß x * to 33 cm in the LER Successfully flattened and maintained HER orbit Raised beam currents [2.45 A (LER), 1.55 A (LER)] & no. of bunches Raised Rf voltages to 3.8 MV (LER), 16 MV (HER) Understand & maintain coupling of the rings.
Staffing (MD) Roster of 20 (engineering-) physicists in AD, with varying fractions of effort on PEP Typically, each person has specialties, e.g. Injection (Decker, Iverson) Optics, lattice (Donald, UW) Collective, HOM (Novokhatski) Vacuum, e-cloud (Kulikov) Backgrounds, IR (Kozanecki, Sullivan) (but not rigid assigments) MD shifts typically staffed by proponents & interested parties includes non-ad people (e.g. NLC, ARD, ESD)
Shift & MD Roster (AD) Brachmann Clendenin Decker Erickson Fisher Iverson Kozanecki Kulikov Luh Novokhatski Pivi Schuh Sonnad Turner Wienands Yocky Ecklund Sullivan Seeman Donald 16 Shift-takers (4 8 shifts/mo./ea.), Program Deputies, MD-shift takers 5 shifts=1 work-week! 4 add l MD-shift takers + experts as needed (rf, ctrl, BaBar) Regular shifts: 1 shifter day & eve + PD MD shifts: as needed up to 5 during day, 0 2 owl
Accelerator Physics Meetings Lattice & Optics (UW) correction & development of present machine optics upgrades (low a, low ß) Beam-beam (JTS, FP) Simulations of operating scenarios Study effect of upgrades Backgrounds (WK) Simulation of existing machine Extrapolation to future conditions Recommendations of remedial measures Provide direction, integrates PEP-effort by AD, ARDA, NLC dept. members.
PEP-II Performance Reviews 2-day meeting happening after run ends Presentations by topic & by system Run performance AP issues System issues Record of proceedings List of Action Items
Run 3 Review Action Items After Run 2003 Review - Action Item List Date Ix Speaker Assign To Item Description Status 11-Jul-07 1 Seeman Kozanecki Figure out cap sigma knob calibration and put in correct value online. Reconcile old knobs done corrected data with John Seeman's luminosity analysis 11-Jul-07 2 Wienands White Make Global Orbit Feedback (GOF) work in trickle mode done 11-Jul-07 3 Wienands Turner Investigate using GOF steering changes to diagnose or find bad BPMs ongoing 11-Jul-07 4 Wienands White Find cause of energy drift by GOF ongoing 11-Jul-07 5 Wienands Donald Make a LER energy knob using correctors (like HER knob) done 11-Jul-07 6 Wienands White In steering, make minimize corrector strength work for PEP rings. 11-Jul-07 7 Wienands Hendrickson Improve HERO and LERO operation. Needs study of how they couple through IP feedback. LERO done 18-Jul-07 8 Sullivan Decker What are orbit bumps that increased luminosity really doing. Need MD?, FJD should give ongoing report. 18-Jul-07 9 Sullivan Faster luminosity feedback would be useful, and could be done with faster hardware. 18-Jul-07 10 Sullivan BBA team Study BPM offsets mostly done 18-Jul-07 11 Stanek Which power supplies are failing, RF PS? ongoing 18-Jul-07 12 Stanek Location dependence of power supply failures ongoing 18-Jul-07 13 Stanek Make friendly page on SCP of Aborts/Day progress 18-Jul-07 14 Stanek OPS/SWE GOF improvements. Display on a separate terminal, Make it a SCP application so its status can be viewed from any SCP SW spec'd, in process 18-Jul-07 15 Op List SWE BPM CUD monitor done 18-Jul-07 16 Op List Standardize doesn't always reproduce rings better often 18-Jul-07 17 Op List SWE RF system - don't know "right" settings in process 18-Jul-07 18 Op List SWE Need better Trickle displays and tools mostly done 18-Jul-07 19 Op List Fisher Tune tracker - switch between pilot and colliding bunches? difficult
Run 3 Action Items (cont d) 18-Jul-07 20 Op List SWE Improved post-abort analysis progress 18-Jul-07 21 Fox v. Winkle Address abort reporting from RF system to get real cause of abort done 18-Jul-07 22 Ecklund Ecklund Look at all thermocouples and predict future heating. Mine data from HSTB files. mostly done (Remigius Karl Mommsen to help mine and analyze data) 18-Jul-07 23 Wienands Decker Find out why LER injection vertical aperture is too small. done 18-Jul-07 24 Wienands Wienands, Turner Look at trickle background in EMC; HER or LER ongoing 18-Jul-07 25 Wienands Chestnut Smooth out trickle-algorithm in BIC, avoid stoppage (including cleaning up BIC-MPG communication). progress 18-Jul-07 26 Wienands Chestnut Get EPICS bar-chart display showing rate of injection/bunch. also want display of total injection rate chart done 18-Jul-07 27 Wienands Controls Get a hardware real-time injection indicator (pulsed LED or counter). 18-Jul-07 28 Wienands Ops Make sure LI03 energy-feedback needs to be updated so feedback is valid for small quanta done 18-Jul-07 29 Wienands Ops Stabilize setup of quanta (intensity, energy). done 18-Jul-07 30 Wienands BaBar BaBar need to update its interlocks (add SIAM) done 18-Jul-07 31 Wienands Weaver Speed up refresh of injection-trigger histograms (Weaver-display). done 18-Jul-07 32 Kozanecki Decker Tune Feed Forward tune vs. I coefficients done 33 Kozanecki Study and fix SLM systematics: HER x, HER y, LER y. 18-Jul-07 34 Kozanecki kozanecki HER IP knobs need calibration. (we are using old Feb 2000 calibration) done 18-Jul-07 35 Kozanecki Fisher Check calibration of tune knobs to tracker measurement 18-Jul-07 36 Kozanecki kozanecki Measure current dependence of single beam tunes part. done 18-Jul-07 37 Kozanecki Wienands Translate SLM sizes to IP size 18-Jul-07 38 Kozanecki BaBar Get IP data from BaBar: (x,y,z, sigma x, sigma z, x-z angle ) done 18-Jul-07 39 Cai Cai, Narsky Put hourglass into beam-beam code to compare with experimental data. Correct experimental data for IP knob calibration. Use correct beta x. done
Beam Aborts Three sources of beam aborts: Rf system trips BaBar-radiation aborts Beam-loss due to instability or tuning error (often causing one of the above) Each abort costs 15 30 min. recovery time about 8 16/pb at the going delivery rate On an ok shift we have 2 2 aborts. 15 30/pb lost (10%) Effective abort reduction is very resource- intensive, esp. in rf/instability area!
Rf Trips since Jan. 2004 D. van Winkle
S. Foulkes, BaBar coll. SVT Trips and Aborts 56% (9/16) of the stable beam fast aborts were SVTRAD aborts
Run 4 Conclusion A lot has been achieved with limited resources PEP performance has doubled during this run Progress with rf stability, trickle injection, beam currents, optics understanding Influx of resources has improved rate of progress On track to exceed plan, reach 10 34 cm -2 s -1 Our operational model is effective flexibility of staff & breadth of experience key. Next year is going to be tougher!
Run 5 Projected Luminosity 160.0 25.0 140.0 20.0 120.0 Lum (/fb) 15.0 10.0 100.0 5.0 Lum (/fb) 80.0 0.0 October NovemberDecember January February Month March April May June S1 60.0 40.0 20.0 0.0 October November December January February March April May June Month
Run 5 Challenges We are getting closer to the hardware limits Thermal loads will double Growth rates will go up 50% (LER) Expectations are higher We will need to fully commission the LER wiggler lattice. More pressure on background control More pressure on lattice improvements ß* reduction damping-partition manipulation
Hardware Projects to Support Run 5 Goals 2 more Rf stations (LER 4-2, HER 12-1 split) HER low-α lattice New LER feedback kickers Upgrade low-level rf, feedback systems New LER SRM Selected vacuum component upgrades
Run 5 PEP-II Parameters Run 5 Now (delivery) Energies e / e+ (GeV) 8.973 3.119 Currents e / e+ (A) Single beam currents (A) 1.8 3.3 1.55 1.4 2.40 (2.45) 2.40 Number of bunches 1700 1600 Bunch currents e / e+ (ma) 1.06 1.94 1.24 2.09 Bunch spacing (m) 1.26 1.26 IP spot size σ * x / σ * y (µm) 155 4.7 147 5 Luminosity ( 10 33 /cm 2 /sec) 15.0 9.21 Tune shift horiz. e / e+ 0.08 0.09 0.059 0.09 Tune shift vert. e / e+ 0.06 0.07 0.031 0.07 Integrated lumi. / 3 shifts (pb 1 ) 777 710 Integrated lumi. / week (pb 1 ) 5440 4295 Integrated lumi. / 7 days (pb 1 ) 5440 4260 Integrated lumi. / month (fb 1 ) 23.3 16.02 Beam crossing angle 0 (head-on) 0 (head-on)
The End