HERA Machine Developement

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HERA Machine Developement

• January-February 2003
• F. Willleke, MHE

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Preliminary HERA Schedule 2003 Preliminary HERA Schedule 2003 Preliminary HERA Schedule 2003 Preliminary HERA Schedule 2003 Preliminary HERA Schedule 2003 Preliminary HERA Schedule 2003
Status of 1/16/2003 1302        
    Begin   Days   End
Startup 2003   2-Jan-03   6   8-Jan-03
Luminosity Operation   8-Jan-03   29   6-Feb-03
Maintenance day   6-Feb-03   1   7-Feb-03
Luminosity Operation   7-Feb-03   10   17-Feb-03
Polarisation Studies   17-Feb-03   14   3-Mar-03
Shut Down   3-Mar-03   126   7-Jul-03
Start-up   7-Jul-03   7   13-Jul-03
Machine Studies   13-Jul-03   14   27-Jul-03
Polarization Studies   27-Jul-03   11   7-Aug-03
Maintenance day   7-Aug-03   1   8-Aug-03
Luminosity Operation   8-Aug-03   27   4-Sep-03
Maintenance day   4-Sep-03   1   5-Sep-03
Luminosity Operation   5-Sep-03   27   2-Oct-03
Maintenance day   2-Oct-03   1   3-Oct-03
Luminosity Operation   3-Oct-03   34   6-Nov-03
Maintenance day   6-Nov-03   1   7-Nov-03
Luminosity Operation   7-Nov-03   27   4-Dec-03
Maintenance day   4-Dec-03   1   5-Dec-03
Luminosity Operation   5-Dec-03   10   15-Dec-03
Machine Studies   15-Dec-03   7   22-Dec-03
Shut Down   22-Dec-03   14   5-Jan-04
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HERA Goals in January/February 2003 last update
January 13, 2003-01-13

• High Priority Items
• Demonstrate, that the IR vacuum and proton
  background conditions is improving by continuous
  running
• Demonstrate safe running with 50mA of Positrons
• Demonstrate a luminosity of at least 4 x 1031
  cm-2 s-1
• Turn on rotators North and South and store and
  accelerate high intensity positron beam
• Demonstrate polarized beams with 3 rotators

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Plan for HERA Machine Studies (update
08.01.2003)

• PARASITIC
• check consistency optics optimization ?operation
• bunch-to-bunch Q_s spread check whether 47kHz
  amplit. mod. of on 208MHz system damps
  longitudinal multibunch instabilities (done)
• test lumi optimization autopilot (looks good)
• test F.Brinkers program for viewing the e orbit
  at IPs
• Test new version of Auto OrbCorr which
  incorporates other than IR-coils
• practice e-ramp lumi procedure with increasing
  current (progress delayed by a least 1 week)
• machine file service (regularly)
• Injection optimization (regularly)

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TODO

• MAXIMUM SPECIFIC (and ABSOLUTE) LUMINOSITY
• condition p-ring towards I_p gt 100mA
• BB-beta-beat minimize BB-beta-beat with phase
  trombone prepare an optics with fixed phase
  shift in the west
• measure BB tune shift and L_spec vs. proton bunch
  current with collisions at only one IP at time
• Miscellaneous
• RF-calibration 208MHz 52MHz
• Analyse the 28Hz line that comes from 52MHz
  system 2
• IR-magnet alignment vs. positron current at
  27.5GeV
• understand the -1.5mm horizontal orbit shift at
  H1
• dynamical aperture HERA e/p
• beam based alignment / straight N S
• try to understand phase jumps at QP33 S / QP35 S
  then ORM
• Test improved phase loop-I

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TODO

• MAXIMUM POLARIZATION WITH ALL THREE ROTATOR PAIRS
  
• (N,O,S) (w/o solenoids at first...)
• Re-establish polarization tunes
• measure the dispersion
• scan Qs and Qx for synchrotron sidebands
• phase advance between cavity section
• prepare an optics with fixed phase shift in the
  west
• dispersion e emittance vs. lumi-bump-H4A (H1
  ZEUS) use the wire-scanner measure dispersion
• Vary dispersion in cavities
• POLARIZATION TUNING
• rotator pair OL/OR only
• tunes, orbit, E-scan, harmonic bumps, etc.
• all three pairs tunes, orbit, Energy-scan,
  harmonic bumps, etc.

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TODO

• BACKGROUND STUDIES
• long positron-only run with high initial current
• Vary (up/down) f0 to increase/decrease bunch
  length watching vacuum pressure and H1 beam-pipe
  temperature first tests already
  done in December

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HERA Operational Efficiency

• HERA I had two difficult problems
• Dust problem for electron operation,
  mitigated by replacing the intergrate ion pumps
  by NEG pumps
• Availability of the Accelerator Complex
  Operational Efficiency
  improved by a major upgrade in SD97/98
  addional RF station, new 8kA PS for protons, new
  coils for p low-b quads, DC-bias a sc couplers,
  improvemens in p-Inj line, Improvements in e-Inj,
  ..

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Lessons learnedagrees with Tevatron, SLC, LEP
Experience

• Dont do regular machine study which interupts
  routineoperations
• Dont do frequent regular maintenance
• Dont do long shudowns
• Dont cange operational procedures and
  operational parameters
• Push smoothly and continuously for better
  performance
• Do long runs
• all this was violated for most of
  2002 running

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• Frequent changes of Operation mode (p, e
  only, different bunch patters, high/low
  intensity, with/without collision, scubbing)
• Machine studies severval topics not
  satisfactorily explored in 2001 coupling,
  beam optics verification, beam based alignment,
  e-beam stability, investigation of beam-beam
  effect, e/p injection efficiency

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Injection times improved
Scheduled downtime plus long time vacuum
interventions
Background studies, single beam runs, etc