Fermilab Accelerator Physics Center US LARP Energy Deposition

Fermilab Accelerator Physics Center US LARP Energy Deposition Studies for HL-LHC Nikolai Mokhov DOE LARP Review Fermilab June 1, 2011

OUTLINE Ø Energy Deposition Issues Ø LHC-2 Studies Ø Radiation Damage & Materials Ø 2011 -2015 Plans DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 2

HL-LHC Energy Deposition Issues • IR upgrade: Nb 3 Sn magnet performance, optics and protection system • Higher performance tertiary collimators • Code developments: extrapolation to 7 Te. V, displacement-per-atom (DPA) and gas production modeling, energy deposition Monte Carlo and material response modeling coupling • Benchmarking and beam tests, material response specifically (pulsed and long-term radiation damage, annealing etc. ) DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 3

IR Energy Deposition Issues: LHC vs HL-LHC • Quench stability (peak power density, heat transfer): OK with appropriate protection system • Dynamic heat loads: OK at LHC (30 W/quad) and very challenging at HL-LHC • Radiation damage: Manageable to challenging with appropriate protection system (20 to 100 MGy/yr) • Residual dose rates - Hands-on maintenance: OK at LHC and challenging at HL-LHC N. Mokhov et al. , “Superconducting Magnets in High-Radiation Environment at Supercolliders”, Super Magnets for Supercolliders Workshop, Erice, Sicily, October 2003. N. Mokhov, LARP CM 16, Montauk, May 2011. DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 4

2008 LARP Studies for LHC-2 JIRS aimed at investigation of potential of replacing one (on each side of IP) of the Nb. Ti quadrupoles with a Nb 3 Sn one in the LHC Phase I upgrade of high-luminosity IRs. Based on realistic energy deposition calculations, we were trying to derive operational margins for the quads in various configurations. Simulations were done with MARS 15 (2008), and DPMJET-3 as an event generator for 7 x 7 Te. V ppcollisions at 2. 5 x 1034 cm-2 s-1, using low-betamax and symmetric optics. DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 5

1. LOW-BETAMAX OPTICS: LBM-1 in MARS 15 Q 1: 90 -mm Nb. Ti, 167. 2 T/m, L=7. 06 m Q 2: 130 -mm Nb. Ti, 121. 4 T/m, L=7. 787 m x 2 Q 3: 110 -mm Nb 3 Sn, 176. 2 T/m, L=3 m x 2 TAS aperture: (a) 42 mm (b) 55 mm 3 -mm segment absorbers: W in Q 1, SS in Q 2, no in Q 3 DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 6

2. LOW-BETAMAX OPTICS: LBM-2 in MARS 15 Q 1: 90 -mm Nb 3 Sn, 206. 1 T/m, L=5. 65 m Q 2: 130 -mm Nb. Ti, 121. 1 T/m, L=7. 787 m x 2 Q 3: 130 -mm Nb. Ti, 121. 1 T/m, L=8. 711 m TAS aperture: 55 mm 3 -mm segment absorbers: SS in Q 1, Q 2 & Q 3 DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 7

3. SYMMETRIC OPTICS: SYM-1 in MARS 15 Q 1: 90 -mm Nb 3 Sn, 203. 8 T/m, L=2. 75 m x 2 Q 2: 130 -mm Nb. Ti, 121. 9 T/m, L=7. 8 m x 2 Q 3: 130 -mm Nb. Ti, 121. 9 T/m, L=9. 2 m TAS aperture: 55 mm 3 -mm segment absorbers: SS in Q 1, Q 2 & Q 3 DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 8

90, 110 and 130 -mm Quad Design 110 -mm 90 -mm 130 -mm OPERA-calculated 2 -D magnetic maps: 200, 180 and 125 T/m, Dx = Dy = 2 mm DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 9

Beam screens, segment absorbers, cold bore, kapton, LHE, coils, collar, yoke and cryostat in MARS 15 90 -mm Nb 3 Sn Same scale 130 -mm Nb. Ti Cryostat: thermal shield and vessel (R=457 mm) DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 10

LBM-2 & SYM-1: Peak Power Density in Cable-1 vs z LBM-2 DOE LARP Review - Fermilab, June 1, 2011 55 -mm aperture TAS Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov SYM-1 11

Heat Loads At L=2. 5 x 1034 cm-2 s-1, pp-interactions result in power of 2. 24 k. W per beam carried out from IP 1 and IP 5. About 1/3 of this power is deposited in quads (420 to 460 W) and TAS (326 to 286 W). Double these numbers for the HL-LHC! DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 12

Some 2008 Conclusions 1. For the configurations considered, all the peaks in SC can be kept below the design limits (with protection in). 2. 3 -mm tungsten absorbers in Q 1 provide reduction of peaks by a factor of about 3 and 2 in Q 1 and Q 2, respectively, compared to the stainless steel ones. 3. Compared to the nominal case, dynamic heat loads to the SC quads are certainly higher at 2. 5 x 1034 cm-2 s-1 and enlarged TAS aperture, but – because of larger quad apertures and use of absorbers - seem to be manageable, especially with high-Z absorbers cooled at LN 2 (? ). 4. Using Nb 3 Sn for Q 1 or Q 3 instead of Nb. Ti substantially increases operational margins and frees space for instrumentation between quads. DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 13

Radiation Damage & Materials Growing interest: Mega. Watt facilities, HL-LHC (magnets and detectors) Substantial progress over last several years: Powerful tools for energy deposition, shock waves, cooling and thermodynamics; code coupling; DPA and gas production models and evaluated x-section databases available to the community Issues: Model/code benchmarking; specifics (especially DPA) for energetic charged particle beams; component-dependent critical values; material response (damage and annealing). Can we measure DPA? Can we do better on its modeling? Energy deposition Monte Carlo and material response modeling coupling? Experiments? N. Mokhov, 4 th High Power Targetry Workshop, Malmö, Sweden, May 2 -6, 2011 DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 14

LARP Energy Deposition Studies for HL-LHC It has been agreed at CM 16 in Montauk (May 16 -17) that Fermilab will lead the LARP efforts in this area. Estimated efforts on energy deposition studies for the HL-LHC are about 2 FTE over 5 years. After CM 16, Lucio Rossi proposed and I accepted to formally become a co-cordinator of the WP on energy deposition studies for the HL-LHC project. Lucio: “This will favor the maximum integration among CERN and EU teams on one side and Fermilab and US teams on the other”. First video-conference with CERN is scheduled for June 6. DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 15

Energy Deposition Plan: 2011 -2012 1. Arrive at a first-path consistent model of the inner triplet based on the Nb 3 Sn quadrupoles with all essential details included (optics, magnet geometry, materials, magnetic field maps, TAS, intermediate and inner absorbers). 2. Launch MARS calculations of 3 D distributions in the triplet: power density, accumulated hadron fluence, absorbed dose and DPA, dynamic heat loads and residual dose rates, specifically for the peak values in all critical components (superconductor, stabilizer, insulation). 3. Study tertiary collimators compatible with the HL-LHC parameters. 4. Code developments: extrapolation to 7 Te. V, displacement-per-atom (DPA) and gas production modeling, energy deposition Monte Carlo and material response modeling coupling; benchmarking. 5. Launch R&D program on beam tests for collimator, superconducting, stabilizing and insulating materials, on material response specifically (pulsed and long-term radiation damage, annealing etc. ) DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 16

Energy Deposition Plan: 2013 -2015 1. Thorough MARS calculations to optimize the triplet configuration, quad design and protection system. 2. Same for tertiary collimators. 3. Further model/code developments and benchmarking. 4. MARS studies of possible performance improvement via additional elements such as mid-plane low-Z spacers, non -uniform liners, modified cooling channels, ceramic insulation, further refined TAS etc. 5. MARS calculations to support beam tests and relate their outcome to the LHC environment. DOE LARP Review - Fermilab, June 1, 2011 Energy Deposition and Nb 3 Sn IR Ouads for HL-LHC - N. Mokhov 17