RHIC Detector Upgrades

1. RHIC Detector Upgrades S. Aronson 8/5/02

2. From the RHIC Program Review Close-out: 2) Plans for upgrading the RHIC Facility The RHIC physics program is just starting. The compelling scientific case for the overall RHIC II upgrade has not been made.Nevertheless, there are some detector upgrades that are already clear because they are driven by the availability of new technology (e.g. faster electronics, computers, etc.) or by specific physics topics that could be addressed with minimal enhancements to existing detectors. Limited running time and data analysis has occurred to date on RHIC experiments. As a result it is not obvious that the full extent of detector upgrades required for RHIC II is yet understood to the level that the cost estimates are accurate. It is also not clear that expenditures for upgrades have been balanced against expenditures for additional weeks of machine operations. This balance should be addressed by BNL with input from the user community and PAC with the goal of optimizing the program to get the most “bang for the buck.” The relative priorities of the various upgrades for various experiments should then be established based upon the possible physics gains and costs.

3. From the RHIC Program Review Close-out: It is not obvious that the RHIC II accelerator and detector upgrades should logically be lumped together into one big project. On the accelerator side, there are many accelerator R&D issues that must be resolved prior to the start of a construction project. We were told that some projects like EBIS are ready for execution ($17M) and may result [in] substantial savings both in operations and in maintenance of the existing Tandems, while others like electron cooling in RHIC are less developed. On the detector side, there are some upgrades driven by the planned x40 increase in luminosity, while others could be useful and add physics at present luminosities. The schedules shown at the review for RHIC II seem to be very optimistic. It seems premature to try to define and baseline all upgrades as one big project. Particularly until more information is available from the first Phase of RHIC operations. Recommendation: BNL and DOE should examine the plans, timescale and scope of RHIC II. The elements of the RHIC II program should be physics driven.

4. From the RHIC Program Review Close-out: Recommendation: BNL and DOE should establish a mechanism for making priority ordered lists of detector and accelerator upgrades with the priority established based upon physics arguments for the upgrade, cost and time scale. BNL should work with the DOE to develop methods to fund these incremental projects. The amount of detector R&D funds available in the FY 03 President’s budget allows the BNL Physics Department to spend $0.5 to 1.0M of detector R&D in FY03. Most of this would be pointed at detector upgrades that would allow operation at higher luminosity. It was not shown exactly what the FY03 funds would be used for or what would be delayed if less [than] the desired $1.0M were available. Recommendation: Physics and detector performance driven arguments should support the plans and level of BNL spending on detector R&D activities.

5. RHIC Future Physics… • RHIC Phase I will be maturing in 2005 – 2006 • Complete initial runs with Au-Au, p-p, d-Au, energy scan, light ions • Explore Heavy ion reactions in a new domain • Global event characteristics • Properties of “hard” physics in A+A • Discovery phase of the QGP search • Establish the early equilibration of matter • Demonstrate several characteristic signatures of the QGP • Compare with p-A (d-A) • Begin the core Spin program with full machine capability for polarized protons. From T. Ludlam’s talk at the RHIC review

6. The Next Phase… RHIC as a Nuclear QCD Machine: • High luminosity A-A, p-A, polarized p-p • Measure the essential properties of the quark-gluon plasma, and associated phase transitions • Explore the early phases of reaction dynamics in QCD matter formation • New phenomena in bulk QCD matter • Extended studies of nucleon spin structure • Facility requirements: • Luminosity and duty factor improvements to allow A A samples ≥ 10 nb-1 • Upgraded PHENIX, STAR detectors • New sensitivity to hard scattering, heavy flavors, rare processes From T. Ludlam’s talk at the RHIC review

7. RHIC II… Measurements Beyond the Initial Exploratory Phase High Pt and Q2: Leading particle spectra to Pt ~30 GeV/c Direct photons to Pt > 20 GeV/c Photon-tagged jets…jet tomography Drell-Yan at M ~5 GeV Rare probes: Many x1000 upsilons W production in AA pA pp Very large unbiased event samples: Low mass lepton pairs γγ interferometry… Direct EM radiation from plasma Disoriented Chiral Condensate; Strong CP violation Extended detector capability: Open charm… Vertex resolution ~0.05 mm Flavor tagging of jets… PID at high Pt Low mass lepton pairs; Low Pt Direct Photons…Dalitz pair rejection Observables at forward rapidity for spin and pA physics…Forward coverage: tracking, PID Data samples ~10 nb-1 … Design Lum. (Au Au) … ~160 weeks 4 x L0 … 40 weeks 40 x L0 … 4 weeks From T. Ludlam’s talk at the RHIC review

8. Enhancements possible with existing machine: Double the number of bunches to 112 Decrease b* from 2 m to 1m RHIC II Luminosity Upgrade Plan 4x increase in ave. L; Still limited by I.B.S. Electron beam cooling at full RHIC energy will eliminate intra-beam scattering effects and reduce beam emittance: 10x increase in average luminosity Evolution of Au Au parameters: Luminosity in units of 1026 cm-2sec-1 Current in units of 1010 ions/beam From T. Ludlam’s talk at the RHIC review

9. Detector Upgrades… Rough Time Scale PHENIX/STAR R&D DAQ/FEE/trigger upgrades Vtx/PID/tracking upgrades STAR Replace TPC Silicon Inner Tracker TPC/Hadron-blind detector/Aerogel PHENIX DAQ/Trigger upgrades From T. Ludlam’s talk at the RHIC review

10. Call for proposals: RHIC Detector R&D Proposals are solicited for R&D funds in support of detector technologies for the future physics program of the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. Detector upgrades to exploit the enhanced machine performance will require advances in the present state of technology in areas of tracking, particle identification, data acquisition, and trigger capability. These issues were discussed at a workshop entitled “R&D for Future Detectors and Upgrades” held at Brookhaven in November 2001. A summary of the workshop can be found on the web at www.star.bnl.gov/STAR/rhicworkshop/. An R&D program is called for, similar in scope and scale to that which preceded the initial round of RHIC detector construction. It is expected that dedicated detector R&D funding for RHIC will be made available over the next several years to facilitate the construction of major detector upgrades during the latter half of this decade. In order to initiate this program, the BNL Physics Department is calling for proposals for R&D funding, beginning in FY 2003. These proposals should address long lead-time technology developments that are viewed as essential for the upgrade of the RHIC detectors, or the implementation of new detectors, over the remainder of this decade. Proposals should be submitted to Dr. Samuel Aronson, Chair, BNL Physics Department, by September 20, 2002. From T. Ludlam’s talk at the RHIC review

11. Call for proposals: RHIC Detector R&D BNL will incorporate these proposals into a single plan, including some shared R&D where appropriate, that will be forwarded to DOE on behalf of the RHIC community. Brookhaven expects to convene a Detector R&D Advisory Committee that will meet in October or November 2002 to review this plan and make recommendations for FY 2003 allocations. This committee would meet regularly, at least once per year, to monitor progress, review new proposals, and make recommendations for allocations in subsequent budget cycles. Proposal Guidelines: It is understood that individual detector collaborations may be submitting proposals for several R&D projects. These should be submitted under a single umbrella document that serves to tie the proposed R&D to the physics goals and upgrade plans of the collaboration. The document should map out the R&D needs for the next 3 years (2003-2005). Each proposed R&D project should have a statement of its value for the future RHIC physics program, and a justification for the need and timeliness of the R&D. It should also include (to the extent possible at this stage) a budget estimate for labor, materials, travel, and subcontracts, an estimate of the schedule to carry out the work, and should list the principal investigators or groups who will carry out the work. From T. Ludlam’s talk at the RHIC review

12. RHIC Facility Upgrade Plan… As Presented to NSAC LRP Workshop From T. Ludlam’s talk at the RHIC review