RHIC APEX & LARP

RHIC APEX & LARPRHIC APEX & LARP

Vladimir ShiltsevFNAL/APD

APEX Mtg 11/02/2006 - Shiltsev 2

RHIC

NSRLLINAC

Booster

AGS

Tandems

STAR6:00 o’clock

PHENIX8:00 o’clock

PHOBOS10:00 o’clock Jet Target

12:00 o’clock

RF4:00 o’clock

BRAHMS2:00 o’clock

RHIC high L(polarized) hadron collider

Operated modes (beam energies):

Au–Au 10, 28, 31, 65, 100 GeV/n

d–Au* 100 GeV/n

Cu–Cu 11, 31, 100 GeV/n

p–p 11, 31, 100, 205, 250 GeV

Possible future modes:

Au – Au 2.5 GeV/n (AGS, SPS c.m. energy)

p – Au* 100 GeV/n (*asymmetric rigidity)

Achieved peak luminosities (100 GeV, nucl.-nucl.):

Au–Au 581030 cm-2 s -1

p–p 351030 cm-2 s -1

Other large hadron colliders (scaled to 100 GeV):

Tevatron (p – pbar) 231030 cm-2 s -1

LHC (p – p, design) 1401030 cm-2 s -1


Performance limitations with partial to-do list

Intra-beam scattering (heavy ions) Low dispersion lattice Stochastic (in progress) and electron cooling at 100 GeV/n

Dynamic pressure rise from electron clouds NEG coating of warm sections Pre-pumping of cold sections

Instabilities (at transition) Adjust chromaticity (chromaticity jump?) Reduce electron clouds Fast transverse damper

Beam-beam (light ions and protons) Eliminate ~10 Hz orbit oscillation (in progress) Non-linear chromaticity correction (in progress) New working point ? Electron lens ??

Polarization (protons) AGS: strong partial snake AGS: horizontal tune in spin tune gap (in progress) RHIC: 100 GeV: RHIC: 250 GeV: ring alignment, orbit correction


Run-7 (President Budget request) (Q3)30 weeks of cryo operation

1 ½ week cool down 80K to 4K

3 week set-up/ramp-up A-A

½ week warm-up

10 weeks p-p physics

3 weeks set-up/ramp-up p-p

12 weeks of A-A physics

Over last five years reduced cool-down/warm-up from 5 weeks to 2 weeks and reduced set-up/ramp-up from 2x5 weeks to 2x3 weeks total reduction of operations overhead from 15 weeks to 8 weeks per year!

LN2 cooler, He refrigerator improvements Automation, beam-based feed-back


Goals for RHIC Enhanced Design Performance (~2008*) (Q4)

* First 250 GeV p-p physics run currently scheduled for 2009.


LARP Accel Systems Progress ‘06

• Schottky being baked, will go into LHC tunnelSchottky being baked, will go into LHC tunnel• TCFB: success at SPSTCFB: success at SPS• 4 long-term hardware commissioners @CERN• SLAC joins commissioning forces• LHC@FNAL to open in Nov’07, new - LAFS• RC work at full speed, a lot of changes, delay• SPS beam studies: BBQ PLL, Q’ head-tail, bent

crystal, etc• Wires built for RHIC tests• # of LARP presentations at Valencia workshop


Accelerator Systems FY07 Priorities

1. Lumi-Monitors: build,install, start commissioning, RHIC test

2.2. Tune&Coupling FB: deliver design, participate in Tune&Coupling FB: deliver design, participate in

installation and commissioninginstallation and commissioning

3. Schottky: participate in installation and commissioning

4. Hardware Commissioning: execute current plan – SAFELY!

5. Beam Commissioning: develop acceptable/detailed

execution plan for FY08+ by mid-07 (more from BNL!) – (more from BNL!) –

Todd, MeiTodd, Mei

6.6. Physics experiments: Physics experiments: RHIC (BBLR),RHIC (BBLR), Tevatron(PLL), ecloud Tevatron(PLL), ecloud

7. Other tasks: execute Task Sheet’s Plans


RHIC BBLR wires – assembly

wires (2.5m long) with strong-back (-profile) 7 support points

NEG coated chambersduring assembly


Planned test with RHIC BBLR wires (WF)

1. Better signal from LR interaction(include head-on BB as another nonlinearity, larger chromaticity)

2. RHIC BBLR wire commissioning(may be partially parasitic to operation, may improve collimation)

3. Use wires to simulate LHC-like conditions(wires designed for LHC strength, beam lifetime better than in SPS tests)

4. Test compensation of single LR interaction

(in presence of head-on collision, need protons)

5. Test pulsed power supply [not in 2007](confirm that beam lifetime is not negatively affected)


Lumi-Mon Noise w. and w/o beam (Angelika D) 0.1mV 100mV

no beam beam, 1 rev.


Noise Problem (w. beam)

5 MHz/div20 db/div

9.5 MHz 19 MHz 28 MHz 46 MHz


???


Estimate of SyncRad Suppression effect (WF)

[H. Burkhardt, CERN]

Energy loss from synchrotron radiation ~ Z2,makes heavy ions in RHIC particularly interesting


AGS “Cooling” (Mike Bl)In the mid 90s Willem Van Asselt observed a narrowing of the IPM

profiles with gold beams over the AGS injection porch. The time scale was of order one second and the data were seen by several people.

In 1995 K. Kilian published a paper suggesting that collisional excitation of electronic states could cool beams.

A very cursory AGS study in 2005 showed no emittance reduction.Theory has been pessimistic. C-A/AP/230

IPM neutralization??; IBS ??

RHIC APEX & LARP

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