MI Reactor Core Configuration(s) Structural Support & Vacuum Pumping C. Priniski, C. Gentile, F. Dahlgren Princeton Plasma Physics Laboratory UCSD January 30 th -31 st, 2007

Current Thinking: 10 m John Sethian MI Chamber 1/23/07 A.E. Robson 1/26/07

PPPL HAPL 16 Configuration

Vacuum Vessel Structure Internal Component Approximate Weights 17Li-83Pb Conical Blanket: Density of Breeder: 8650 kg/m^3 1 Blanket volume: ~130.6 m 3 Blanket weight: 1.12 million kg, or 1,245 tons FliBe Conical Blanket: Density of Breeder: ~1990 kg/m 3 2 Blanket volume: ~same 130.6m 3 Blanket weight: 260,000 kg, or 287 tons Internal Neutron Shielding 75% weight steel: Weighing about 252,000 kg, or 278 tons 1. ITER Documentation Series No 29, IAEA, Vienna 1991 "Blanket, Shield Design and material Data Base. 2. Proposal of a Blanket concept based on FliBe and advanced ferritic steel, APEX Meeting, San Diego, April 17-19, 2002

Vacuum Vessel Structure FEA Analysis Upper Shell SST Under Vacuum & Structural Loads Total deflection ~ 8 mm for 1.5 inch thick vessel

Chamber Maintenance Accomplished through domed (upper and lower) flange diameter allows removal of small coil Four laser ducts removed (all optics remain in place) Requires modular consumable components (blanket, ion dumps) Allows for toriodal ion dump vacuum pumping

HAPL 16 Givens and Druthers:

16th HAPL - Magnetic Intervention Chamber General conceptual arrangement for the magnetic intervention chamber

Baseline Design of Cusp Coils Cable in Conduit Conductor (CICC) comprised of Nb-Ti superconductor with a forced flow super-critical LHe coolant High current density option is considered if AC fields are not present in the coil windings and a much lower current density configuration if a 5 Hz AC field is present (currently under investigation) Coil and case will be force-cooled with K LHe An additional LN2 shroud will be positioned around the coil structure and support columns to be a thermal shield Radiation and neutronics studies* suggest that a minimum 50 cm thick water/316L-SS shield required between SiC blanket and coil Other coil conductor options, including use of Rutherford cable and HTS YBCO are also under consideration *per M. Sawan, U.W., HAPL Meeting, GA, August 8-9, 2006 Typical CICC Nb-Ti Conductor for ITER

Alternate conductors Figure 2.11*: The LHC Rutherford cable for the outer layer of the main dipole magnets, quadrupole magnets and busbars: 36 strands, width 15.1mm, (1.9K, 9tesla)12900A, = mm, strand twist pitch 10.5cm. A short longitudinal section is shown on the top; the trapezoidal cross-section on the bottom. J typ = kA/sq.mm I = 12kA/cable A typical Rutherford-type cable (NbTi) is used in most HEP S.C. coils * A. Devred. Superconductor development in europe. Proceedings of the Workshop on VLHC Magnets, FNAL, 2000.

Alternate conductors HTS offers the promise of higher fields, current densities, & 77 o K operation Higher heat 77K should reduce (eliminate?) requirements for quench protection/detection. Current commercial application: Synchronous Condensers for power industry Currently YBCO S.C. is available in 20meter lengths with Cu stabilized 3-ply or with Stainless 3-ply construction. AMSC is projecting km lengths by late ‘07 Compiled by P.Lee, et.al., U.Wisconsin, FSU, NHFML

Alternate conductors MgB2 is a mid-temperature range S.C. (up to 39 K) Practical conductor lengths are becoming available (1-4 km) in quantity (Hyper Tech anticipates their production capacity to be >500 km/yr. this year). Columbus S.C.,SpA of Genoa Italy has produced 18km of S.C. in >1.5 km lengths for an open MRI magnet. Has the advantages of high thermal margin & lower cost than NbTi or Nb3Sn conductors. J c = K - 4Tesla. Hyper Tech Research, Inc. info.: Hyper-Tech MgB2 Conductor Columbus MgB2 Conductor - ASG

Alternate conductors ITER Nb3Sn CICC

Cusp Field Coil Analysis COIL A Z NI FZ FR/L FZ/L S-HOOP COMBINED M M AT N N/M N/M N/M SQ STRESS IN IN AT LB LB/IN LB/IN PSI PSI DFL-R E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E-02 Axial (vertical) loads = 8.1 MN on the smaller coils, = 45.1 MN on the larger radius coil set. Coils would be self supporting against radial loads Coil weight = 35 tons for 3.4 Meter coils, 61 tons for 6 Meter radius, 192 tons total (4 coils) Inductance: Coil#1 = henries, Coil#2 = henries Stored energy: Coil#1 = 5.5 MJ, Coil#2 = 45.6 MJ Cryogen refrigeration (wag) ~ 1-2kW, ~10kg/hr (rad. Heating?)

Very rough cost estimate of Cusp Coils A rough cost estimate of coil fabrication NbTi$ 350/lb 15% OFHC Cu$ 3.12/lb 65% Jacket$ 180/lb 20% Coil Fabr.$ 1100/lb Additional costs for instrumentation, coil design and joint development, quench protection, and structural support, cryo-plant, plumbing, power supplies, etc. TFC =184000(350* *0.20+3*0.65) * = 219 M$ * Table I-3a From: M.I.T. Plasma Science and Fusion Center Report PSFC/RR-99-6

High Current Density Option

Low Current Density Option

Conclusions and Path Forward Investigate conceptual design of a magnet system which will produce a sufficient cusp shaped field for the deflection of the charged products from a direct drive inertial fusion target Further refinements of the design will address:  radiation/lifetime  structural supports  busing/joint configuration  fault and quench protection  cryogen & refrigeration requirements  feasibility and economies of alternative conductor options

ITER- Cost Info 10 B$ machine cost ~1/2% PF2 (2coils).005x10e9 = 50M$ For NbTi conductor for PF-2 coil only Assume another M$ for fabrication 120M$ for two coils

ITER- Coil Info

ITER Cost Info

ITER conductor info

Current cost10-year Projected cost NbTi ~1.5 $/kA m0.76 $/kA m 5T) Nb 3 Sn ~15 $/kA m 4 $/kA m YBCO ~200 $/kA m (‘06) 50$/kA m (by ‘08?) Possible cost/kg 5-10 years out:  Niobium-based: ~$160/kg ($350/lb)  MgB 2 <$50/kg ($110/lb) ?, <$0.10/m Relative S.C. cost in $/kA-Meter Alternate conductors -costs

ITER Conductor Info

Super Conductors Advancing Critical Currents in Superconductors December Compiled by Peter J. Lee University of Wisconsin-Madison Applied Superconductivity Center Nb-Ti: Example of Best Industrial Scale Heat Treated Composites ~1990 (compilation) Nb-Ti(Fe): 1.9 K, Full-scale multifilamentary billet for FNAL/LHC (OS-STG) ASC'98 Nb-44wt.%Ti-15wt.%Ta: at 1.8 K, monofil. high field optimized, unpubl. Lee et al. (UW-ASC) ‘96 Nb-37Ti-22Ta: at 2.05 K, 210 fil. strand, 400 h total HT, Chernyi et al. (Kharkov), ASC2000 Nb 3 Sn: Bronze route VAC filament, non-Cu 0.1µW·m 1.8 K J c, VAC/NHMFL data courtesy M. Thoener. Nb 3 Sn: Non-Cu J c Internal Sn OI-ST RRP #6555-A, 0.8mm, LTSW 2002 Nb 3 Al: Nb stabilized 2-stage JR process (Hitachi,TML- NRIM,IMR-TU), Fukuda et al. ICMC/ICEC '96 Nb 3 Al: JAERI strand for ITER TF coil Bi-2212: non-Ag J c, 427 fil. round wire, Ag/SC=3 (Hasegawa ASC2000+MT ) Bi 2223: Rolled 85 Fil. Tape (AmSC) B||, UW'6/96 Bi 2223: Rolled 85 Fil. Tape (AmSC) B|_, UW'6/96

References 30 Nb-Ti: K for whole LHC NbTi strand production (CERN-T. Boutboul) Nb-Ti: K for whole LHC NbTi strand production (CERN, Boutboul) Nb-Ti: Nb-47wt%Ti, 1.8 K, Lee, Naus and Larbalestier UW-ASC'96 Nb-37Ti-22Ta, 2.05 K, 50 hr, Lazarev et al. (Kharkov), CCSW '94. Nb 3 Sn: Non-Cu J c Internal Sn OI-ST RRP 1.3 mm, ASC'02/ICMC'03 Nb 3 Sn: Bronze route int. stab. -VAC-HP, non-(Cu+Ta) J c, Thoener et al., Erice '96. Nb 3 Sn: 1.8 K Non-Cu J c Internal Sn OI-ST RRP 1.3 mm, ASC'02/ICMC'03 Nb 3 Al: JAERI strand for ITER TF coil Nb 3 Al: RQHT+2 At.% Cu, 0.4m/s (Iijima et al 2002) Bi-2212: non-Ag J c, 427 fil. round wire, Ag/SC=3 (Hasegawa ASC-2000/MT ) Bi 2223: Rolled 85 Fil. Tape (AmSC) B||, UW'6/96 Bi 2223: Rolled 85 Fil. Tape (AmSC) B|_, UW'6/96 YBCO: /Ni/YSZ ~1 µm thick microbridge, H||c 4 K, Foltyn et al. (LANL) '96 YBCO: /Ni/YSZ ~1 µm thick microbridge, H||ab 75 K, Foltyn et al. (LANL) '96 MgB 2 : 4.2 K "high oxygen" film 2, Eom et al. (UW) Nature 31 May '02 MgB 2 : Tape - Columbus (Grasso) MEM'06 slide#9: ITER IFDA mtg. Geneva,7 June’06-A.Portone,E.Salpeitro Bromberg, L., Shultz,J., - Aries Stellerator Talk Lee,P. - UW, Madison, NHMFL (compiled slide#9) Devred, A. Superconductor development in europe. Proceedings of the Workshop on VLHC Magnets, FNAL, American Supercon, Inc. Columbus S.C.,SpA Hyper Tech Research, Inc.

9.74*10 6 liters 1.29*10 6 liters 6.5m Toroidal Duct (MI 1.0) 5.72*10 6 liters 11m Laser Ports (BDC) 6.11*10 5 liters 5m Plenum Ducts (FTF) Chambers Evaluated for VPS Advanced MI Chamber Laser Ports

Issues/Items/Concepts Magnetic Shielding for TMPs - Design completed to shield < 50 gauss Neutron Shielding for TMPs - Depends on final configuration Heat loading on TMPs - Depends on final configuration Total Gas Load on Chamber - Propellant gas, Expendable Sabots, Target size, rep rate, First wall off-gassing Pumping Capacity- Conductance issues Mechanical Pumping- Mechanical/Cryo Hybrid? Chamber Bakeout System

Typical Zones for High Vacuum Pumpdown IFE Range Source Vacuum Labs

System Specifications : Cylindrical Vessel, Beam Port Pumping  MI Target Chamber Dimensions Inner radius = 6.5 m Target chamber volume  9.74x10 6 liters Total laser duct volume  0.18x10 6 liters Total volume (with 40 beam ports)  9.92x10 6 liters  Target Chamber Pressures Operational base pressure = 0.5 mtorr Gas load  120 torr-liters/sec (Full Size Targets) Total system in-leakage < 1x10 -5 torr-liters/sec

Vacuum Pumping System: Cylindrical Vessel, Beam Port Pumping MI Target Chamber Pumping TMP pumping through beam ducts TMP’s (Varian-V 6000) = 2 TMP’s /duct TMPS’s total =72 TMP backing pumps (mechanical dry pumps) = 1/6 TMP’s Backing pumps total = 12 Outboard Beam Duct Pumping TMP’s (Varian-V 2000 HT) - number TBD by final duct volume/configuration

Beam Port Pumping Operational Pressure Beam Port Pumping P 500 = 1.2 mtorr

System Specifications : Bi-Conic Chamber, Toroidal Pumping  MI Target Chamber Dimensions Inner radius = 6.5 m Target chamber volume  3.3x10 6 liters Total laser duct volume  0.18x10 6 liters Total volume (with 40 beam ports)  3.48x10 6 liters  Target Chamber Pressures Operational base pressure = 0.5 mtorr Gas load  120 torr-liters/sec (Full Size Targets) Total system in-leakage < 1x10 -5 torr-liters/sec

Vacuum Pumping System: Bi-Conic Chamber, Toroidal Pumping MI Target Chamber Pumping TMP pumping through beam ducts TMP’s (Varian-V 6000) = 60 Below Toroidal Ion Dump TMPS’s total =60 TMP backing pumps (mechanical dry pumps) = 1/6 TMP’s Backing pumps total = 10 Outboard Beam Duct Pumping TMP’s (Varian-V 2000 HT) - number TBD by final duct volume/configuration

Toroidal Pumping Operational Pressure Toroidal Pumping P 500 = 0.48 mtorr

50 m

Nations Largest Nuclear Reactor Goes to Direct Drive Inertial Fusion Energy