RHIC%20APEX%20 - PowerPoint PPT Presentation

Title: RHIC%20APEX%20


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RHIC APEX LARP

• Vladimir Shiltsev
• FNAL/APD

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RHIC high L(polarized) hadron collider
Operated modes (beam energies) AuAu 10, 28,
31, 65, 100 GeV/n dAu 100 GeV/n
CuCu 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.) AuAu 58?1030 cm-2 s
-1 p?p? 35?1030 cm-2 s -1 Other large
hadron colliders (scaled to 100 GeV) Tevatron (p
pbar) 23?1030 cm-2 s -1 LHC (p p,
design) 140?1030 cm-2 s -1
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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 ?

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Run-7 (President Budget request) (Q3)
30 weeks of cryo operation
½ week warm-up
12 weeks of A-A physics
10 weeks p?-p? physics
3 week set-up/ramp-up A-A
3 weeks set-up/ramp-up p?-p?
1 ½ week cool down 80K to 4K

• 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

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Goals for RHIC Enhanced Design Performance
(2008) (Q4)
First 250 GeV p?-p? physics run currently
scheduled for 2009.
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LARP Accel Systems Progress 06

• Schottky being baked, will go into LHC tunnel
• TCFB success at SPS
• 4 long-term hardware commissioners _at_CERN
• SLAC joins commissioning forces
• LHC_at_FNAL to open in Nov07, 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

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Accelerator Systems FY07 Priorities

1. Lumi-Monitors build,install, start
   commissioning, RHIC test
2. TuneCoupling FB deliver design, participate in
   installation 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!) Todd, Mei
6. Physics experiments RHIC (BBLR), Tevatron(PLL),
   ecloud
7. Other tasks execute Task Sheets Plans

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RHIC BBLR wires assembly
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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)

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Lumi-Mon Noise w. and w/o beam (Angelika D) 0.1mV
?100mV
no beam
beam, 1 rev.
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Noise Problem (w. beam)
5 MHz/div
20 db/div

9.5 MHz 19 MHz 28 MHz
46 MHz
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???
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Estimate of SyncRad Suppression effect (WF)
Energy loss from synchrotron radiation
Z2,makes heavy ions in RHIC particularly
interesting
H. Burkhardt, CERN
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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 ??