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eRHIC Ring-Ring Cost Estimates. K.Dow, W.A.Franklin, E. Ihloff, J.Kelsey, J.B.van der Laan , R.Milner, C.Tschalaer, E.Tsentalovich, D.Wang, F.Wang MIT-Bates Linear Accelerator Center. Workshop on Future Prospects in QCD at High Energy BNL, June 17-22, 2006. Cost Estimates. Include: Design
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eRHIC Ring-Ring Cost Estimates K.Dow, W.A.Franklin, E. Ihloff, J.Kelsey, J.B.van der Laan, R.Milner, C.Tschalaer, E.Tsentalovich, D.Wang, F.Wang MIT-Bates Linear Accelerator Center Workshop on Future Prospects in QCD at High Energy BNL, June 17-22, 2006
Cost Estimates • Include: • Design • Procurement • Hardware delivered to the lab • Some magnets (quads) magnetically mapped. • Does not Include • Installation • Commissioning • Contingency
COST (injection system) Injection Options 2 GeV Copper Linac 2-10 GeV Ramping Ring M$ 40 *) *) including extra costs for ramping the storage ring 5 GeV Copper Linac + Recirculation 5-10 GeV Static Ring M$ 110 5 GeV Superconducting Linac + Recirculation 5-10 GeV Static Ring M$ 150 1-2 GeV Copper Linac 1-10 GeV Ramping Booster Ring (Figure 8 ?) 5-10 GeV Static Ring M$ 90
Accelerator options Recirculating NC linac Recirculating SC linac M$ 110 M$ 150 Figure 8 booster synchrotron M$ 90 *) *) simple circular booster (no polarized injection): M$ 30
Bottom up costs estimates (arcs) • Assembling “notebook” of quotations/component costs • No RF, high power vacuum chambers, tunnel, … • Costs as delivered to the laboratory – no installation. Costs: 59 k$/m
Costs Estimates: Main Ring Scaled from APS 7 GeV ring
Top Down Cost Estimates Top down scaling from construction of other accelerators Swiss Light Source Booster Swiss Light Source Argonne Booster Bates SHR JLAB TESLA Reasonably consistent with bottoms up estimates Large variability in injector due to choice of injector • eRHIC • 10 GeV Main Ring M$ 150 • Injector 2 GeV M$ 50 • 10 GeV M$ 150
Ring circumference / power load At 20 GeV circumference grows to 3.8 km = RHIC
Ring circumference / power load (cont.) B-factory power load Length enlarged to limit power load to a ‘reasonable’ value
Cost scaling for higher energies Length enlarged to limit power load to a ‘reasonable’ value
Re-usage PEP ring components • Parameters/specifications • PEP-II <-> eRHIC lepton ring • Possible usage of PEP-II components • Magnet / power converters • RF • Feedback • Vacuum • Instrumentations / controls • (Injector / transport lines)
eRHIC lepton ring vs. PEP-II rings eRHIC PEP II (HER, LER) • Ring type: collider lepton rings • Energy range: 5~10 GeV 3-9 GeV • Beam currents: 0.5 ~ 1A 1.5 ~ 3 A • Bunch currentsimilar • # bunches 120 1722 Beam dimensions: emit.: ~50 nm rad b_ave: ~15 m (arc, rf) • Collective effects: similar In general, technical approaches are very similar.
Magnets, Power supplies Thanks to similar beam dimensions (beam stay clear), PEP magnets in general are suitable for eRHIC. Both physical apertures and magnetic field specifications are comparable eRHIC 100 50 20 20 2.0 1e-3 10 5
Magnets, Power supplies, con’t • Almost the same length and aperture as used in eRHIC ZDR • Almost all quadrupoles can be used. • Also most ring sextupoles and correctors. • Dipoles are likely NOT usable (Superbends!)
RF System • PEP-II-type RF system is a called a favorable option for eRHIC in ZDR • Impedance, Collective effects, HOM heating, etc with PEP-II-type cavities are done in ZDR • PEP II Cavities (476 MHz) can be tuned up to 478.5 MHz, well within the range we need (478.2 – 478.5) (Bob Rimmer) • Klystrons may have narrower bandwidth, but with ‘minor modifications’ a tube could be tuned to meet the requirements at 478.5 MHz.’ (Peter McIntosh, under discussion • The number of cavities is enough for eRHIC
RF System, con’t The existing RF system in PEP-II is good for eRHIC (total voltage, power, etc.) RF system in a high intensity lepton ring accounts for about 20% of total cost of machine. (So this is a real cost saver)
Feedback system • To suppress beam instabilities, both transverse and longitudinal bunch-by-bunch feedback systems are needed. • PEP-II feedback systems are good enough for the lepton ring of eRHIC, whose collective effects are comparable to those in PEP II • multi-bunch instabilities, thanks to longer bunch spacing may be less
Vacuum system • Similar requirements for eRHIC e-ring and PEP-II • vacuum level, • beam current, • lifetime, • radiation power, • considerations on collective effects • etc. • Comparable Power Load, BUT dipole chambers have different curvatures (160 versus 80 m, apart from Superbends) • Other vacuum components can be used, e.g., pumps, gauges, photon stops, etc. Worthwhile ? Always
Instrumentation, Control System, … In principle instrumentation usage is always suitable, bpm’s ion clearers, tune measurement, … Integration of instrumentation / controls into eRHIC for RF, magnets, vacuum system etc. should be straightforward, using EPICS control system
Summary, usage PEP parts • A fair amount of PEP II components could be used • Savings: 20-30 % • Remember: There are always extra costs for re-usage!