# Presentation: 689540

## Acceleration beyond 100 GeV

- Goal
- To evaluate the spin dynamics beyond 100 GeV
- What’s the impact of 1mm rms orbit distortion(achieved) on the polarization transmission efficiency?
- How much can we correct the orbit with the existing RHIC orbit correction system at higher energy?
- To provide a guidance/justification for the full ring re-alignment of RHIC during summer of 2005
- Expection
- Little or no polarization is expected at energy of 205 GeV with 1mm orbit distortion
- Polarization ramp measurement will be the key technique in exploring the depolarization mechanisms and locations.

## Machine Configuration for pp to 205 GeV

- Energy
- Injection: 46.5
- Store: 391.5
- Working point
- Ramp I: 28.72, 29.73 (injection to 100 GeV)
- Ramp II: 28.68, 29.69 (100 GeV to 205 GeV)
- Store: 28.68, 29.69
- Lattice: IP 6 8 10 12 2 4
- Injection: 10 10 10 10 10 10
- Store: 2.0 2.0 10 5 3 10
- Collision Pt (option): 6 8 10
- RF:
- No re-bucketing at store

## Plan for 205 GeV development 

- Ramp development
- Goal:
- Adjust tunes, chromaticity, orbits and etc to maximize the beam transmission efficiency
- Keep the tunes stay in the snake-resonance free region and minimize the orbit distortion as much as possible
- Polarization ramp measurement once a working ramp is available. Expect to use 2 ramps
- Estimate time: 9 consecutive shifts

## Plan for 205 GeV development 

- Polarization development
- Goal:
- Understand the spin dynamics beyond 100 GeV. This will allow us to benchmark our simulation model and provide guideline.
- Task list
- Measure the polarization as a function of orbit distortion around 135 GeV where a strong intrinsic resonance is
- Intrinsic resonance strength: 0.3 for a 10 pi mm-mrad particle
-  imperfect: 0.12 for 1mm rms orbit distortion
- 4 datapts: 0.5mm, 1mm, 2mm, 4mm
- Keep Qy at 0.68
- 12 ramps in total: 2 shifts
- Measure the polarization as a function of tune with an fixed orbit distortion
- The orbit distortion will depend on the previous study
- 4 datapts: 0.74, 0.70, 0.67
- 10 ramps in total: 2 shifts

## Schedule: May 31 0800 – June 3 0800

- May 31 0800 – May 31 2400
- 8 bunch ramp development
- Adjust orbits/tunes/chromaticities along the ramp to maximize transmission efficiency
- Global decoupling along the ramp
- Tunes: Qx=0.69, Qy=0.68
- Orbits: rms ~ 0.5mm or better
- Separation bump through the ramp
- May 31 2400 – June 1 1600
- Global decoupling along the ramp
- Local IR non-linear correction
- June 1 1600 – June 2 0800
- 56 bunch ramp development
- Fine adjustment of tunes/chromaticities
- Polarization measurement along the ramp
- Collision setup
- Cog beam into collision, fine adjust orbits/optics to minimize the beam decay
- June 2 0800 – June 2 1600
- Store setup: IP6, IP8, IP10
- Steering setup
- Collimation setup
-  June 2 1600 – June 3 0800: store at 205 GeV

## RHIC Shift leader Schedule

- May 31 0800 – May 31 1600: Todd
- May 31 1600 – May 31 2400: Vadim
- May 31 2400 – June 1 0800: Yun
- June 1 0800 – June 1 1600: Fulvia
- June 1 1600 – June 1 2400: Jorg
- June 1 2400 – June 2 0800: Mei
- June 2 0800 – June 2 1600: Angelika

## Timeline for 205 GeV development

- 4/17

- Ramp development
- (9 shifts)

- Polarization development

## Challenge of going beyond 100 GeV

-  p=217 GeV
- This gives the same Brho
- as Cu and one can avoid
- an additional DX magnet
- training

- Intrinsic spin resonance
- Qx=28.73, Qy=29.72, emit= 10

- achieved

## Machine Configuration for pp to 170 GeV

- Energy
- Injection: 46.5
- Store: 324.5
- Working point
- Ramp: 28.72, 29.73
- Store: 28.68, 29.69
- Lattice: IP 6 8 10 12 2 4
- Injection: 10 10 10 10 10 10
- Store: 2 2 10 5 3 10
- Collision pt: 6 8
- RF:
- No rebucketing at store