1QM2006

D.I.Lowenstein

RHIC:The Path Forward

Presented to

Quark Matter 2006Shanghai, PRC

Derek I. LowensteinBrookhaven National Laboratory

November 15, 2006

2QM2006

D.I.Lowenstein

The Present RHIC

3QM2006

D.I.Lowenstein

RHIC

NSRLLINAC

Booster

AGS

Tandems

STAR

PHENIX

PHOBOSJet Target

RF

BRAHMS

RHIC – a high luminosity hadron collider

Operated modes (beam energies):Au–Au 10, 28, 31, 65, 100 GeV/nd–Au* 100 GeV/n Cu–Cu 11, 31, 100 GeV/np–p 11, 31, 100, 205, 250 GeVPossible 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 (2x design)p–p 351030 cm-2 s -1 (7x design)Other large hadron colliders (scaled to 100 GeV):Tevatron (p – pbar) 251030 cm-2 s -1

LHC (p – p, design) 1401030 cm-2 s -1

EBIS

Electron cooler

4QM2006

D.I.Lowenstein

Delivered luminosity and polarization during last 5 years (Q3)

15%

34%46%

47%

65%

Expect x2 Au ion luminosity increase in the 2007 run

5QM2006

D.I.Lowenstein

The Evolution of RHIC

6QM2006

D.I.Lowenstein

Path ForwardShort term (2007-2008)

Luminosity increase Stochastic cooling complete Increase number of bunches

>x2 for ions; >x2 for polarized protonsMid term (2009-2010)

RHIC II Phase 1 efforts completed EBIS injector operational Major detector upgrades completed

RHIC II Phase 2 efforts started electron cooling construction started

Longer term (2011-2015) RHIC II completed eRHIC Project started

7QM2006

D.I.Lowenstein

Goals for RHIC Enhanced Design Performance (2008*)

1. Au-Au L store average= 8 x 1026 cm-2s-1 @ 100 GeV/n

2. p -p L store average=150 x 1030 cm-2s-1 @ 250 GeV

3. P store average = 70%

4. 60% of calendar time in store = 100 hours/week

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

8QM2006

D.I.Lowenstein

Stochastic cooling can counteract IBS by keeping the emittance constant while electron cooling will shrink the emittance.Improves RHIC performance by providing more luminosity (20-50%) improved vertex size, and longer stores and reduced number of refills. Improves productivity.

Time domain (oscilloscope) and frequency domain (spectrum analyzer) measurements confirm cooling

Cooling time about 1 hour

Bunch profile before (red) and after (blue) cooling, Wall Current Monitor

Schottky spectrum before cooling: blue traceSpectrum after cooling: red trace

Stochastic cooling of a high frequency bunched beam has been observed for the first time.

9QM2006

D.I.Lowenstein

EBIS Injector Project New RHIC preinjector system: EBIS replaces 30+ year old tandems

Joint DOE and NASA funded project. Construction begun in 2006. Improves performance

Extends mass range to uranium Allows for polarized He3 injection

Commission in 2009

EBIS test stand

10QM2006

D.I.Lowenstein

The RHIC experiments have learned to utilize elemental QCD processes generated in the collisions themselves, such as…

• formation and transport of heavy quarks, and quarkonium bound states

• fragmenting jets from high energy partons

• high energy photons

Typically these are rare probes:Future progress requires well-defined improvements in detector capability and machine performance. T. Ludlam

q

q

Why RHIC II ?

11QM2006

D.I.Lowenstein

RHIC II electron cooling

Electron cooling of ion beamsIncreases the luminosity for heavy ions by a factor of ten

Based on a high energy, 54 MeV and 50 mamp, energy recovery linac (ERL) and a superconducting photoelectron gun

Preparing for DOE CD0 decision in early FY2007

Superconducting RF Cavity Ampere Superconducting RF Gun

12QM2006

D.I.Lowenstein

Electron-cooling facility at IP2

ERL

RHIC triplet

Cooling region

100 m

RHIC triplet

ERL

Electron cooling R&D

13QM2006

D.I.Lowenstein

A New Generation of DIS: High luminosity polarized Electron-Nucleon/Electron-Ion Collider

• Gluon and sea quark polarization• The role of orbital angular momentum

• Gluon momentum distributions in nuclei• Gluons in saturation• The color glass condensate

Electron-proton collisions

Electron – Ion collisions

T.Ludlam

Why eRHIC?

14QM2006

D.I.Lowenstein

eRHIC at BNL

A high energy, high intensity polarized electron (and positron) beam to collide with the existing heavy ion and polarized proton beam.Would significantly enhance RHIC’s ability to probe fundamental, universal aspects of QCD

•Ee = 10 GeV (~5-12 GeV variable) TO BE BUILT•Ep = 250 GeV (~50-250 GeV variable) EXISTS•EA= 100 GeV/nucleon (for Au) EXISTS•At least one new detector for ep & eAAt least one new detector for ep & eA TO BE BUILTTO BE BUILT

15QM2006

D.I.Lowenstein

eRHIC Design Concepts

simpler IR design multiple IRs possible Ee ~ 20 GeV possible1034 luminosity

Ring-Ring design Linac-Ring design

simpler ring design one IR possible less R&D effort1033 luminosity

2 designs are under consideration

16QM2006

D.I.Lowenstein

eRHIC Variable beam

energy Proton-to-uranium

ion beams! Proton, He3(EBIS)

polarization 1034 luminosity

eRHIC

Jlab12GeV

eRHIC CM Energy vs Luminosity

17QM2006

D.I.Lowenstein

eRHIC ZDR

Reviewed June 2005 (252 page document)

Collaboration: BNL, MIT-Bates, BINP & DESY

Goals: initial design, identify & investigate most crucial R&D problems for challenging luminosities and IR design

http://www.bnl.gov/eic

18QM2006

D.I.Lowenstein

Path Forward Schedule

RHIC II