# Presentation: 674578

## 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

## RHIC Layout and dAu Geometries

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

_***BRAHMS/pp2pp***_

_***STAR***_

_***PHENIX***_

**AGS**

_***PHOBOS***_

_***RF***_

**Tandems**

**Booster**

- Pol. H- Source

**Linac**

**d**

**Au****12+**

**d**

**Au****79+**

- foil

## 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

- 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

**RHIC FY03 Deuteron-Gold Chronology**

## RHIC FY03 Deuteron-Gold Performance Goals

| Storage Parameter | Au, Yellow Ring
    Goal        Achieved | d, Blue Ring
    Goal          Achieved |
| --- | --- | --- |
| Intensity/bunch
Total Intensity
Transverse 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] | 2/3
100
56
2
20 | 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  |

## RHIC Deuteron-Gold Integrated Luminosity

## 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 Week

## 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

## 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

| # 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 | 1
3 | 14.0x1026
4.7x1026 | 3.0x1026
1.0x1026 | 70.0 (ub)-1
23.3 (ub)-1 |
| 56 | 0.7 | 15-40 | 1
3 | 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