Very Large Hadron Collider

Transcription

1 Very Large Hadron Collider Don t eat the your seed corn! Ernest Malamud f Fermilab Accelerator R&D Oversight Group September 30, 1999 (1 st meeting)

2 Presentation Ernie Malamud Introduction Summary of budget requests A few details not covered by my colleagues Peter Limon High-field R&D program Materials development Connections to long-term goal of building vlhc Bill Foster Low-field R&D program Connections to long-term goal of building vlhc A couple of possible intermediate steps -- by exploring these in detail, one better understands technical challenges and costs Gerry Jackson The Energy Tripler Bob Noble The Tevatron Tripler A few concluding remarks We will address the points in Steve s memo: Long term goals of the R&D program R&D goals for FY 00 Required M&S funding to meet these goals Required staff support to meet these goals

3 What is vlhc? National collaboration Mission Statement The Steering committee for a future very large hadron collider coordinates efforts in the United States to achieve a superconducting proton-proton collider with approximately 100 TeV cm and approximately 1034 cm-2sec-1 luminosity. The U.S. site of the vlhc is assumed to be Fermilab. Using a nominal 20x in dynamic range: 150 GeV MI 3 TeV vlhc Booster 3 TeV vlhc Booster 50 TeV vlhc

4 Lots of progress Discussions of the next energy frontier collider Indianapolis 94: the role of radiation damping "New low-cost approaches to High Energy Hadron Colliders at Fermilab." Mini-Symposia APS Annual Meeting, Indianapolis. Snowmass 96 Very Large Hadron Collider Physics and Detector Workshop. March 13-15, Fermilab "Accelerator Physics Issues in Future Hadron Colliders." "Hadron Colliders Beyond the LHC." Mini-Symposia APS Annual Meeting, Columbus. In response to recommendations of the HEPAP Subpanel Report on Planning for the Future of U.S. High-Energy Physics, February 1998 (Gilman Panel) Steering committee for a future very large hadron collider formed. BNL: Michael Harrison, Stephen Peggs FNAL: Peter Limon, Ernest Malamud LBNL: William A. Barletta James L. Siegrist Cornell: Gerry Dugan Discussions underway to enlarge membership of Steering Comm.

5 Working Groups formed; each has now held a workshop: Magnets for a Very Large Hadron Collider, Co-convenors: Bill Foster, Ron Scanlan, Peter Wanderer Port Jefferson, LI, NY, Nov , 1998, Peter Wanderer, Chair VLHC Workshop on Accelerator Technology Co-convenors: Chris Leemann, Waldo Mackay, John Marriner Thomas Jefferson National Accelerator Facility, Newport News, VA, Feb. 8-11, 1999 John Marriner, Chair VLHC Workshop on Accelerator Physics Co-convenors: Alan Jackson, Shekhar Mishra, Mike Syphers The Abbey, Fontana, WI, Feb , 1999 Mike Syphers, Chair VLHC Annual Meeting Naval Postgraduate School, Monterey, CA June 28-30, 1999 Bill Barletta, Chair Annual Report setting R&D goals for next year expected Oct. 15. Proceedings of the 3-workshops -- Compilation of papers -- Tentatively planned for a similar set of workshops and an annual meeting covering new work

6 Why VLHC? Hadron Colliders are the "Discovery Machines" for HEP. They probe deeper than any other type of accelerator. The W and Z were first observed at the SppS. The top quark was discovered at the Tevatron. It may be possible to discover Light Higgs and SUSY particles at the Tevatron in Run II. LHC will extend the mass reach with 7x in E cm.

7 Luminosity Eichten, Hinchliffe, Lane, Quigg (1984) made the case for a rich physics menu for the SSC at 40 TeV E cm and A 100 TeV vlhc is a factor of (2.5) 2 = 6.25 in s. Thus is the appropriate figure to set as a working parameter. The discovery reach of such a machine is enormous. The Giant Microscope and Public Support We need to learn how to communicate better to our constituencies. The giant microscope metaphor is one way. At a 100 TeV vlhc can see contact interactions at a scale of >32 TeV (Bauer & Eno),.... perhaps as high as the E cm or Λ c ~ 100 TeV 1/Λ c ~ 2 x cm σ ~ 1/Λ c 2 ~ 40 fb 1 year (30% duty cycle) at yields 100 fb -1 or 4000 events Today the luminosity of is detector limited. With history as a guide, 1-2 decades after the machine has operated at 10 34, major detector and accelerator upgrades will take place raising the luminosity to or higher. The main accelerator upgrade may be to the abort system because of the large stored energy in the beam; however, by then it is likely that brighter beams will be achieved by new cooling methods, making this problem easier to cope with.

8 Generic Accelerator Tunneling R&D at Fermilab ****DRAFT PRE-PROPOSAL G.W. Foster/M. May Aug 99**** TeV Dual Tunnel 40 TeV 6 TeV

9 Not only the tunnel is generic Much of the machine/magnet design is expandable to other energies and geometries Assume One new tunnel (for now) Go off-site (find out if this is possible) 150 GeV 3 TeV 2.0 Tesla 93% pf C = 38 km 1 TeV (replace later) 20 TeV 2.0 Tesla 93% pf C = 225 km continuum between these much 3 TeV/2T work applies to other scenarios however, there is a break point in this continuum ~ 0.5 B$?? modest niche experimental program higher than LHC physics case easier to make might be saleable politically -- USA#1 Upgrade path: when high field magnets available Single turn injection Modest dynamic range Argues for a bigger circumference tunnel 12 T Magnets, 72% pf E = 15 TeV E cm = 30 TeV 2 x LHC 12 T Magnets, 72 % pf E= 93 TeV E cm = 186 TeV (may not be feasible because of synchrotron radiation)

10 Magnets: the heart of the matter Recently several schemes have evolved that utilize low and high field magnets in a vlhc complex Low-field, 2T, iron-dominated gaps possibly lower $/TeV including tunnel -- one of the R&D goals is to determine this cost faster cycling; more suitable as an injector possible fixed target mission for intermediate machine High-field, T, conductor-dominated gaps requires development of new materials; longer time-scale smaller geographical extent; possibly less difficult politically at collision energy, advantages of synchrotron radiation damping

11 Magnets: the heart of the matter Factors in choosing the magnet strength collider energy accelerator physics issues superconducting material availability and cost magnet costs synchrotron radiation choosing the collider energy allows one to examine the role of synchrotron radiation in more detail For a 50 TeV + 50 TeV collider Low-field (2.0 T superferric): Damping time too long to be helpful However, allows alternating gradient structure with no problems from anti-damping High-field (> 10 T): synchrotron radiation puts power into the cryogenics synchrotron radiation makes the beam emittance smaller Other factors that need evaluation to properly understand the role of synchrotron radiation: ground motion dipole field noise intra-beam scattering quantum fluctuations in the synchrotron radiation fill and ramp times (before synchrotron radiation comes into play)

12 Magnet R&D programs: different paths to a common goal Superconductors Low field NbTi is ideal for the low-field vlhc J c at low field has increased 10x since Tevatron built (driven by MRI market) Cost is probably < $1 /ka-meter High, very high field Material development is the key issue HTS: BSSCO, YBCO LTS: (A15 Conductors) Nb 3 Sn, Nb 3 Al Fermilab Low-field NbTi superferric B ~ 2 T Other interesting ideas for superferric machines: KEK, JINR Fermilab High-Field Nb 3 Sn cosθ B ~ 11 T Brookhaven Very high field B ~ 12.5 T Goal: based on future development of YBCO "conductor friendly" common coil Lawrence Berkeley Lab Very high field B > 13 T various materials being tried: Nb 3 Sn, Nb 3 Al, BSCCO "conductor friendly" common coil Texas Stress management B ~ 16 T

13 The Fermilab low field (2.0 T, transmission-line magnets) program is making progress. Test loop in the MW-9 building built using surplus SSC conductor. Tested successfully at 100 ka August 30, 1999 The loop has a removable 4-m section in which various transmission lines can be tested.

14 Excellence of the Fermilab site Existence of the injector chain Excellent Geology Fermilab region geology predictable rock and tunneling conditions, relatively homogenous rock mass extensive local experience in the TARP tunnels (> 100 miles under Chicago) no settlement problems at the depths being considered rate of movement of groundwater in the dolomite layer we are considering for the collider is very small (aquatard)

15 Tunnels and Choice of tunnel size lowest cost room for other machines Sufficient room for installation and maintenance Operating the machine will certainly imply the use of robotics; just how much robotics is used is a matter of economics. Conventional TBM/Conveyor belt tunneling we have used the specific siting and depth of the 3-TeV lowfield tunnel as a model to investigate tunnel costs we are using detailed cost model from Kenny Construction to understand cost drivers a recent study by the Robbins Company gives optimism that this cost (per meter of tunnel) can be significantly reduced Exploration of new methodologies in tunneling and muck removal