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RHIC FY03 Deuteron-Gold Performance. RHIC Deuteron-Gold Performance Run Description/Chronology Performance Goals Achieved Luminosity Delivery RHIC Performance Limitations FY04 Au-Au Operations Projections http://www.rhichome.bnl.gov/AP/RHIC2003. MP6. MP7. RHIC Layout and dAu Geometries.
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RHIC FY03 Deuteron-Gold Performance • RHIC Deuteron-Gold Performance • Run Description/Chronology • Performance Goals Achieved • Luminosity Delivery • RHIC Performance Limitations • FY04 Au-Au Operations Projections http://www.rhichome.bnl.gov/AP/RHIC2003
MP6 MP7 RHIC Layout and dAu Geometries BRAHMS/pp2pp PHOBOS • Different species, Z/A provided new challenges in RHIC setup • Injection with both equal rigidities and equal frequencies STAR RF PHENIX d Au79+ Booster Pol. H- Source Linac AGS Tandems foil d Au12+
RHIC FY03 Deuteron-Gold Chronology 11/1 Start of RHIC cooldown 12/3 Blue ring at 4K, deuteron injection 12/13 Deuterons accelerated to flattop; Both rings at 4K 12/22 First ramps of d/Au to collision energies 12/24 First d/Au collisions at all experiments 12/27 Start of routine detector commissioning 1/9 Routine 110 bunch ramping 1/12 Start of 2003 d/Au Physics Run 2/21 Low-noise storage RF driver 2/22 Deuteron transverse instability fixed 2/22 First production store to hit goal levels 2/26 Return to 56 bunch operations; routine goal operations 3/24 End of FY03 d/Au Physics Run
d merge 110 55 RHIC Deuteron-Gold Intensity Performance • Injector dAu “mode switch” time usually 3-5 minutes, below goal
RHIC Deuteron-Gold Initial Luminosities dAu operations routinely exceeded program goal performance
RHIC Deuteron-Gold Typical Stores • 1-2 hours between stores, <5 minutes switch between d and Au • Luminosity lifetime (~4h) dominated by Au lifetime, debunching, IBS
RHIC Deuteron Beam Transverse Instability • kHz-MHz transverse instabilities created emittance growth • New instrumentation provided near-immediate performance increase
Fill 3 Fill 2 Fill 1 RHIC Beam Experiments Program • Focus on RHIC performance/upgrades, facility-driven beam physics • e.g. pressure rise/intensity limitations study (Zhang, Iriso-Ariz, Fischer,…) • Fill 1: 16 bunches+[4 empty]+..., Fill 2: 12+[8]+..., Fill 3: 14+[6]+... • Pressure rise of Fill 2 is lower than Fill 1. • Fill 3: bunch length is longer and intensity is lower.
RHIC Deuteron-Gold Performance Limitations • Vacuum pressure rise • Total intensity limited to 100-110 109 Au equivalent • Limits deuteron-gold operations to 56 bunches/ring • Transition instabilities • Coherent bunch oscillations drive beam growth/reduce luminosity • Corrected with machine tuning Feb 23 in deuteron beam • Longitudinal instabilities • Leads to factors 2–3 in diamond size, damp with “Landau cavities” • Intrabeam scattering (Au beam) • Transverse/longitudinal emittance growth => electron cooling • Beam-beam tuneshift and tune spread • First strong-strong hadron collider since ISR • Likely present limitation to polarized proton performance
RHIC FY04 Au-Au Operation Projections • RHIC planning indicates a likely long FY04 Au-Au run • Almost all performance goals reached in FY03 dAu run • Demonstrated *=1m in FY02 Au-Au run, FY03 pp run • Injector ramp-up time for Au intensity is indicated • Operations on possible threshold of vacuum instabilities • Solenoids, bakeout, beam scrubbing are feasible solutions • RHIC Retreat: June 10-12 2003