Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 1 Fri May 16 2003

RHIC FY03 Deuteron-Gold PerformanceRHIC 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

Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 2 Fri May 16 2003

RHIC Layout and dAu GeometriesRHIC Layout and dAu Geometries

Different species, Z/A provided new challenges in RHIC setup Injection with both equal rigidities and equal frequencies

BRAHMS/pp2pp

STARPHENIX

AGS

PHOBOS

RF

MP6 MP7Tandems

BoosterPol. H- Source

Linac

d Au12+

d Au79+

foil

Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 3 Fri May 16 2003

11/1 Start of RHIC cooldown12/3 Blue ring at 4K, deuteron injection12/13 Deuterons accelerated to flattop; Both rings at 4K12/22 First ramps of d/Au to collision energies12/24 First d/Au collisions at all experiments12/27 Start of routine detector commissioning1/9 Routine 110 bunch ramping1/12 Start of 2003 d/Au Physics Run2/21 Low-noise storage RF driver2/22 Deuteron transverse instability fixed2/22 First production store to hit goal levels2/26 Return to 56 bunch operations; routine goal operations3/24 End of FY03 d/Au Physics Run

RHIC FY03 Deuteron-Gold ChronologyRHIC FY03 Deuteron-Gold Chronology

Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 4 Fri May 16 2003

RHIC FY03 Deuteron-Gold Performance GoalsRHIC FY03 Deuteron-Gold Performance Goals

Storage Parameter Au, Yellow Ring Goal Achieved

d, Blue Ring Goal Achieved

Intensity/bunchTotal IntensityTransverse Emittance [95% rad]Bunch Length [ns] (200 MHz RF)

1.0x109 0.7x109

55x109 38/60x109 10-40 10-30 5 5

0.8x1011 1.1x1011 45x1011 57/69x1011 15 12 5 5

Machine Performance goal achieved

Setup/Ramp-up time [weeks]Storage Energy [GeV/u]Number of bunches* [m]Diamond length [cm]

2/310056220

2.5/3 100

110/56 2/3/4

15 Peak luminosity L [x1028 cm-2 s-1]<L>(store) [x1028 cm-2 s-1]<L>(week) [nb-1/week]

4.0 (5.0)1.6 (2.0)4.0 (5.0)

7.2 2.2 4.6

Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 5 Fri May 16 2003

RHIC Deuteron-Gold Integrated LuminosityRHIC Deuteron-Gold Integrated Luminosity

Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 6 Fri May 16 2003

RHIC Deuteron-Gold Intensity PerformanceRHIC Deuteron-Gold Intensity Performance

55110

d merge

Injector dAu “mode switch” time usually 3-5 minutes, below goal

Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 7 Fri May 16 2003

RHIC Deuteron-Gold Initial LuminositiesRHIC Deuteron-Gold Initial Luminosities

dAu operations routinely exceeded program goal performance

Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 8 Fri May 16 2003

RHIC Deuteron-Gold Typical WeekRHIC Deuteron-Gold Typical Week

Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 9 Fri May 16 2003

RHIC Deuteron-Gold Typical StoresRHIC 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

Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 10 Fri May 16 2003

RHIC Deuteron Beam Transverse InstabilityRHIC Deuteron Beam Transverse Instability

kHz-MHz transverse instabilities created emittance growth New instrumentation provided near-immediate performance increase

Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 11 Fri May 16 2003

RHIC Beam Experiments ProgramRHIC 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.

Fill 2

Fill 3

Fill 1

Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 12 Fri May 16 2003

RHIC Deuteron-Gold Performance LimitationsRHIC 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

Brookhaven Science AssociatesU.S. Department of Energy

Todd Satogata 13 Fri May 16 2003

RHIC FY04 Au-Au Operation ProjectionsRHIC FY04 Au-Au Operation Projections

# bunches Ions/bunch[x109]

Emittance[rad]

*[m]

Lpeak

[cm-2 s-1]Lave(store)[cm-2 s-1]

Lave(week)[week-1]

56 1.0 15-40 13

14.0x1026

4.7x1026

3.0x1026

1.0x1026

70.0 (ub)-1

23.3 (ub)-1

56 0.7 15-40 13

7.0x1026

2.4x1026

1.5x1026

0.5x1026

35.0 (ub)-1

11.7 (ub)-1

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