P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 1 Outline A quick review of the VLHC oA short description oSome important technical points The VLHC in a global plan for HEP oHow & why a VLHC fits into a global plan Some remarks on planning for HEP oPromoting huge accelerator projects in today’s political climate is very difficult. We make it more difficult by pursuing a flawed strategy. How can we make it better?
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 2 Design Study for a Staged Very Large Hadron Collider Fermilab-TM-2149 June 11,
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 3 The Staged VLHC Concept Take advantage of the space and excellent geology near Fermilab. oBuild a BIG tunnel. oFill it with a “cheap” 40 TeV collider. oLater, upgrade to a 200 TeV collider in the same tunnel. Spreads the cost Produces exciting energy-frontier physics sooner & cheaper Allows time to develop cost-reducing technologies for Stage 2 Creates a high-energy full-circumference injector for Stage 2 A large-circumference tunnel is necessary for a synchrotron radiation-dominated collider. This is a time-tested formula for success Main Ring TevatronLEP LHC
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 4 Conclusions (1) A staged VLHC starting with 40 TeV and upgrading to 200 TeV in the same tunnel is, technically, completely feasible. There are no serious technical obstacles to the Stage-1 VLHC at 40 TeV and luminosity. oThe existing Fermilab accelerator complex is an adequate injector for the Stage-1 VLHC, but lower emittance would be better. (We should take this into account if Fermilab builds a high-power injector. Low emittance is important!) oVLHC operating cost is moderate, using only 20 MW of refrigeration power, comparable to the Tevatron. oImprovements and cost savings can be gained through a vigorous R&D program in magnets and underground construction.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 5 Conclusions (2) The construction cost of the first stage of a VLHC is comparable to that of a linear electron collider, ~ $4 billion using “European” accounting. oFrom this and previous studies, we note that the cost of a collider of energy near 40 TeV is almost independent of magnetic field. oA total construction time of 10 years for Stage-1 is feasible, but the logistics will be complex. oMaking a large tunnel is possible in the Fermilab area. Managing such a large construction project will be a challenge. oBuilding the VLHC at an existing hadron accelerator lab saves significant money and time.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 6 Conclusions (3) The Stage 2 VLHC can reach 200 TeV and 2x10 34 or possibly significantly more in the 233 km tunnel. oA large-circumference ring is a great advantage for the high- energy Stage-2 collider. A small-circumference high-energy VLHC may not be realistic. oThere is the need for magnet and vacuum R&D to demonstrate feasibility and to reduce cost. Result of work completed after the “Study.” oFor very high energy colliders, very high magnetic fields (B>12T) are not the best solution.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 7 VLHC Parameters
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 8 Transmission Line Magnet 2-in-1 warm iron Superferric: 2T bend field 100kA Transmission Line alternating gradient (no quadrupoles needed) 65m Length Self-contained including Cryogenic System and Electronics Cabling Warm Vacuum System 30cm support tube/vacuum jacket cry pipes 100kA return bus vacuum chamber SC transmission line
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 9 The First Stage-1 Magnet Yokes
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 10 VLHC Tunnel Cross Section
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 11 Underground Construction Three orientations chosen to get representative geological samples of sites near Fermilab. oSouth site samples many geologic strata and the Sandwich fault. oOne north site is flat and goes through many strata. oOther north site is tipped to stay entirely within the Galena- Platteville dolomite, and is very deep. These are not selected sites – merely representative. oCost of other sites can be built from data gained in these sites.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 12 EAST-WEST SECTION
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 13 VLHC Cost Basis Used the “European” cost base oNo detectors (2 halls included), no EDI, no indirects, no escalation, no contingency – a “European” base estimate. Estimated the cost drivers using a standard cost-estimating format. This is done at a fairly high level. oUnderground construction (Estimates done by AE/CM firm) oAbove-ground construction (Estimates done by FNAL Facility Engineering Section) oArc magnets oCorrector and special magnets (injection, extraction, etc) oRefrigerators oOther cryogenics oVacuum oInteraction regions Used today’s (2001) prices and today’s technology. No improvements in cost from R&D are assumed.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 14 VLHC Stage 1 Cost Drivers Comparison: the SSC Collider Ring, escalated to 2001 is $3.79 billion * Underground construction cost is the average of the costs of three orientations, and includes the cost of a AE/CM firm at 17.5% of construction costs.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 15 Stage-2 Magnets There are several magnet options for Stage 2. Presently Nb 3 Sn is the most promising superconducting material. Stage-2 Dipole Single-layer common coil Stage-2 Dipole Warm-iron Cosine
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 16 Stage-2 Cost & Performance What are the general design ideas that exist for magnets for the Stage 2 VLHC? We did not make a cost estimate of the Stage 2 VLHC, but we tried to understand major cost sensitivities. oFor example, how does the cost vary as a function of magnetic field? After the “Study,” we did some work to help understand the limitations of Stage 2 performance. oDoes synchrotron radiation put limits on performance, or does it influence the choice of magnetic field? Can detectors live in the radiation field? These questions were studied to help guide future R&D.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 17 VLHC Cost based on SSC cost distribution
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 18 Synchrotron radiation Synchrotron radiation masks look promising. They decrease refrigerator power and permit higher energy and luminosity. They are practical only in a large-circumference tunnel. A “standard” beam screen will work up to ~200 TeV and ~2x Beyond that, the coolant channels take too much space. A synchrotron radiation “mask” will allow even higher energy and luminosity. Coolant
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 19 Magnet aperture required for beam screen and photon stops 200 TeV; 30 km bend radius 14 m magnet length Min. BS-beam clearance=4 mm Diameter increases due to increased coolant flow requirements
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 20 P SR 2 t sr Int/cross < 60 L units cm -2 s -1 VLHC Optimum Field
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 21 Detector Radiation Dose ~ 50 kW (total) at IP
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 22 Stage-2 VLHC Conclusions The Stage 2 VLHC can reach 200 TeV and 2x10 34 or more in the 233 km tunnel. A large-circumference ring is a great advantage for the high- energy Stage-2 collider. A small-circumference high-energy VLHC may not be realistic. oThe optimum magnetic field for a TeV collider is less than the highest field strength attainable because of synchrotron radiation, total collider cost and technical risk. The minimum aperture of the magnet is determined by beam stability and synchrotron radiation, not by field quality. There is the need for magnet and vacuum R&D to demonstrate feasibility and to reduce cost. oThis R&D will not be easy, will not be quick, and will not be cheap.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 23 Next Steps Most important, we must understand the science needs and the opportunities a VLHC presents. oThis workshop is a start! If we ever want a VLHC, we have to keep at the R&D, particularly for high- and low-field magnets, tunneling and vacuum. We need to reexamine our strategy for progress, planning and politics, not only for the VLHC, but for all large facilities.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 24 The HEP Plan We are on the verge of important discoveries oThere are many hints that great physics is just over the horizon — understanding EWSB, neutrino mass, dark energy, dark matter and more — an exciting time. Possibilities for new HEP tools are excellent oRun II is moving ahead (some problems, but getting better) oLHC is being built (with the usual problems) oA renaissance in neutrino physics (New stuff) oA linear collider is being considered (and might be started in 5 to 10 years) Should we include a VLHC in this plan?
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 25 VLHC in the HEP Plan Why do we need to include the VLHC in the HEP plan? oIf we believe that we may eventually want higher-energy collisions at high luminosity, we will almost certainly want a VLHC. The timing and eventual existence of a VLHC will depend on decisions about all other multi-billion-dollar facilities including linear collider. oThe U.S. has the best combination of resources, infrastructure, space and geology for a VLHC. It is difficult to build it anywhere else. oIf a linear collider is built in the U.S. for billions of $, the U.S. is unlikely to spend billions on a VLHC soon after. This results in a long delay for VLHC. oA significant energy upgrade of the LHC will be very costly and very risky, for very little gain. Furthermore, more than VLHC is missing from the plan. oWhat about underground labs, super neutrino beams, astrophysics experiments or R&D for the future? All these should be in the plan.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 26 The HEP Plan We do not have a viable strategy for the survival of HEP. oA global scrap over a linear collider does not constitute a strategy. There has been some recent progress in formulating a path to a linear collider technology decision. We do not even have a plan to make a plan. oIn the U.S., for example, the HEPAP recommendation to create a mechanism to formulate a coherent strategy has become the narrowly-focused P5. HEP must change the way it does things if it is going to survive!
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 27 The HEP Plan Big HEP instruments require more than business as usual oA global strategy derived from a large vision of scientific goals — the “Science Roadmap.” Sell the science, not the instruments. oThe inclusion of a range of scientific disciplines and government policy makers from the beginning. oA fair and open mechanism to modify the roadmap and the plan as results dictate. Why a global strategy? oBig HEP instruments are too costly to be planned, built and operated nationally or regionally. oHEP instruments are complex and take a long time to design and build. Everyone must be involved; everyone must help. oInternational collaboration has many political, human and scientific benefits beyond cost-sharing.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 28 A Word About R&D The machines we are talking about are very costly and very complex. oMistakes and delays are potentially very damaging financially, politically and scientifically. oIt takes longer than you think to develop the components of a cutting-edge collider. The R&D investment for future HEP instruments will be much greater than we are accustomed to.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 29 Conclusions The most important requirement for the survival of HEP is worldwide cooperation resulting in a global strategy based on a visionary science roadmap. Sell the science, not the instruments oLearn from the NASA strategy, in which the goals are truly large and visionary, and the instruments are missions along the way. The parameters and schedule for a VLHC will depend on the timing and location of all other large facilities. The global plan should recognize these couplings. If we ever want to build a VLHC, or any other very large facility, we need to have a vigorous R&D program now. oThe R&D is very challenging, and the penalty for failure will be severe.
P. Limon October 16, 2003 Hadron Collider Workshop 2003 Fermilab 30 Last Slide