Overview of US Activities toward a Future Circular Collider Stuart Henderson FCC Kickoff Meeting February 12, 2014 Thanks to Vladimir Shiltsev, Giorgio Apollinari, Lance Cooley

If you would understand anything, observe its beginning and its development - Aristotle Feb S. Henderson | FCC Kickoff Meeting2

US Collider Activities – Selected Milestones Feb S. Henderson | FCC Kickoff Meeting3

Superconducting Super Collider 87 km, 20 TeV + 20 TeV proton- proton, L ~10 33 cm -2 sec : emerged from Snowmass study 1986: design study complete 1988: Texas site selected and construction began 1993: Project terminated after spending $2B Seventeen shafts were sunk and 23 km (14.6 mi) of tunnel were bored Feb S. Henderson | FCC Kickoff Meeting4

SSC Parameters Circumference87 km Energy per beam20 TeV Magnetic field6.6 T Injection energy2 TeV Luminosity10 33 cm -2 sec -1 N dipole (long/shrt)7956/504 Feb S. Henderson | FCC Kickoff Meeting5

6 CDF DØ Tevatron Main Injector\ Recycler Antiproton source Proton source Tevatron Collider

Tevatron Developments Feb S. Henderson | FCC Kickoff Meeting7

Shiltsev 8 12 fb e32 cm -2 s -1 Total delivered 12 fb -1 to each detector; peak record 4.3e32 cm -2 s -1 Tevatron Performance:

Very Large Hadron Collider: Two Stage Concept 233km tunnel Stage 1: TeV p-p Superferric magnets 2T Tevatron as injector luminosity Stage 2: TeV SC magnets 12T Stage 1 as injector Stage X: VLLC GeV e+e-? Feb S. Henderson | FCC Kickoff Meeting9

VLHC Parameters 10

VLHC Development Activities Feb S. Henderson | FCC Kickoff Meeting11 VLHC Issues: Cost, Photon Stops and IR for 200TeV Beam dynamics at 20 TeV Stage 1 Magnet Development: super-ferric transmission line Stage 2 Magnet

What’s Next? Feb S. Henderson | FCC Kickoff Meeting12

US LHC Involvement The US HEP Community plays a substantial role in the scientific productivity of the LHC Substantial US involvement in the construction of detectors and the accelerator –The US contributed $164 million to the construction of the ATLAS detector and $167 million to the construction of the CMS detector. –The US contributed $200 million to the construction of the Large Hadron Collider. Approximately 2,000 scientists, students, engineers and technicians from 96 US institutions participate in the LHC. –23 percent of the ATLAS, and 33 percent of CMS collaboration members come from American institutions –Since 2008, the work on the ATLAS and CMS experiments resulted in about 230 doctorate degrees for US students. The United States provides 23 percent of the computing power for the ATLAS experiment and 40 percent of the computing power for the CMS experiment. Feb S. Henderson | FCC Kickoff Meeting13

Potential US Involvement in HL-LHC: LARP The US is formulating plans for contributions to the upgrade of the LHC Accelerator and Detectors Several candidate scope elements have been under development Process of convergence among CERN-DOE-U.S. Labs-LARP initiated in Dec ‘2012 Initial consensus on core priorities which makes good use of US accelerator expertise, and which makes critical contributions to LHC luminosity: –Committed to a major stake in 150 mm aperture Nb 3 Sn IR quads –Crab cavities up to the SPS test and possibly beyond to production –High bandwidth feedback was seen as a high impact contribution for modest resources. Back up options: –11 T dipoles Proper “hand-off” if not continued in US –Hollow electron beams for halo removal Support some modest R&D into this effort in the event that circumstances allow its inclusion 14

US Planning Process: A Play In Three Acts Dept. of Energy Scientific Facilities Panel (Dec Feb 2013) –Assessment of facilities which could be constructed in the next decade Community Summer Study, aka “Snowmass” (Aug 2013) sponsored by American Physical Society –Community evaluation of scientific opportunities and strategic goals Particle Physics Project Prioritization Panel (P5) –Official advisory body to the Department of Energy to articulate priorities for High Energy Physics under three budget scenarios Feb S. Henderson | FCC Kickoff Meeting15

Snowmass (from the Executive Summary) Several strategic goals have emerged from the Snowmass study. Probe the highest possible energies and distance scales with the existing and upgraded LHC and reach for even higher precision with a lepton collider; study the properties of the Higgs boson in full detail. Develop technologies for the long-term future to build multi-TeV lepton colliders and 100 TeV hadron colliders. Execute a program with the U.S. as host that provides precision tests of the neutrino sector with an underground detector; search for new physics in quark and lepton decays in conjunction with precision measurements of electric dipole and anomalous magnetic moments. Identify the particles that make up dark matter through complementary experiments deep underground, on the Earth's surface, and in space, and determine the properties of the dark sector. Map the evolution of the universe to reveal the origin of cosmic inflation, unravel the mystery of dark energy, and determine the ultimate fate of the cosmos. Feb S. Henderson | FCC Kickoff Meeting16

Snowmass (from the Executive Summary) The Snowmass study identified, in particular, the promise of a 100 TeV-class hadron collider (VLHC), which would provide a large step in energy with great potential for new insights into electroweak symmetry breaking and dark matter. The feasibility of such a machine should be clarified through renewed accelerator R&D and physics studies over the next decade. Feb S. Henderson | FCC Kickoff Meeting17

Particle Physics Project Prioritization Panel (P5) The P5 Process began in September and is expected to conclude by Spring, addressing the following charge: “…develop an updated strategic plan for U.S. HEP that can be executed over a 10 year timescale, in the context of a 20-year global vision for the field.” “…examine current, planned, and proposed US research capabilities and assess their role and potential for scientific advancement; assess their uniqueness and relative scientific impact in the international context; and estimate the time and resources…needed to achieve their goals.” “…provide recommendations on the priorities for an optimized high energy physics program over the next ten years (FY14-23), under…three scenarios.” “…provide a detailed perspective on whether and how the pursuit of possible major international partnerships (such as LHC upgrades, Japanese-hosted ILC, LBNE, etc.) might fit into the program you recommend…” Feb S. Henderson | FCC Kickoff Meeting18

Technology for Future Colliders US has developed and nurtured a very strong high-field magnet R&D program through DOE/HEP –Nb 3 Sn conductor development program –High-field magnet program for developing accelerator magnets High Field Magnet and LARP programs have brought Nb 3 Sn accelerator magnet technology to the deployment stage for HiLumi Feb S. Henderson | FCC Kickoff Meeting19 High Field Quadrupole SQXF/LQXF 1 m / 4 m long 150 mm bore 11T Dipole Long Quadrupole LQS

Technology for Future Colliders Nb 3 Sn development lays the groundwork for 15T Dipoles Active R&D is underway to extend reach beyond 15 T with HTS Feb S. Henderson | FCC Kickoff Meeting20 Bi-2212 after 100-bar HT 16 T 20 T Extensive development of SCRF technology and capabilities over the last decade, required for e+e- collider concepts D. Larbalestier et. al.

Finally, regarding future U.S. involvement: my views There is broad acknowledgement that any future collider will need to be a global enterprise, requiring resources (financial, human) from across the globe The U.S. community wants to play a role in any future collider –There are several “grass-roots” activities domestically We are concentrating now on making HiLumi a success …and appreciate that the next collider will require considerable effort in design, R&D and garnering support The U.S. community has invested in the critical technologies that will be needed and sees R&D toward future colliders as a high priority A collaborative focus on magnet and SCRF technologies, and the beam dynamics aspects of large hadron and lepton colliders aligns well with US expertise at the national labs and universities Feb S. Henderson | FCC Kickoff Meeting21

Feb S. Henderson | FCC Kickoff Meeting22