1. LARP Magnet Progress Michael Lamm For the LARP Collaboration bnl - fnal - lbnl - slac US LHC Accelerator Research Program All Experimenters’ Meeting Monday, October 8, 2007

2. All Exp. Meeting - 08 Oct 07Michael Lamm on LARP Magnets2 US Accelerator Research Program (LARP)  What is LARP ? US Accelerator Specialist to play role in LHC Accelerator, commissioning, operation and performance upgrades Fermilab AD/APC/TD play major role  Magnet LARP Motivation Existing 70 mm NbTi IR quads will likely be replaced after 4-7 years of operation to increase luminosity We want to play a major role with CERN in developing these magnets

3. All Exp. Meeting - 08 Oct 07Michael Lamm on LARP Magnets3 IR Higher Luminosity Replacement Magnets  IR Environment (low , more interactions)  Wider beam profile, Larger G*dl, Higher energy deposition, More Radiation  Utilize Nb3Sn Superconductor  Improved Nb3Sn magnet technology  Improved Nb3Sn conductor  Rad Hardened structure  Implications for Magnet Design  Wider Aperture, Higher Gradient  Higher field on conductor, SC Temperature Margin, Rad Hardened Materials

4. All Exp. Meeting - 08 Oct 07Michael Lamm on LARP Magnets4 Nb3Sn has been around for a while…. 1960-1990 Nb3Sn/NbTi on parallel path –Alternative for Isabelle –SSC development –LHC 4.2 K Nb3Sn vs. 1.9K NbTi Nb3Sn Tape BNL W. B. Sampson, circa 1967 NbTi Wins! 1990’s Generic R&D to push envelope Twente, LBNL, achieve up to 14. 7 T One of a kind magnets 21st Century, Nb3Sn revisited for future VLHC, LHC upgrade –Conductor improvements in Nb3Sn vs. Field limitations in NbTi –Several participants by now... BNL, FNAL, LBNL,TAMU, CEA, Twente, KEK –10’s of 1 meter models magnets successfully built, mostly in the US…. But never used in an actual accelerator

5. All Exp. Meeting - 08 Oct 07Michael Lamm on LARP Magnets5 LARP 2009 Challenge “Demonstrate that Nb 3 Sn magnets are a viable choice for an LHC IR upgrade”  Technological Quadrupoles (TQ) for performance reproducibility 1 m long, 90 mm aperture Cos(2  ), G nom > 200 T/m, B coil > 12T  Scale up to 4 meter long (LQ) TQs-like cross section and mechanical structure, + experience from two long magnet intermediate studies Milestone set in agreement with CERN  High gradient quadrupoles (HQ) to explore performance limits 1 m long, 90+ mm aperture, G nom > 250 T/m, B coil > 15 T

6. All Exp. Meeting - 08 Oct 07Michael Lamm on LARP Magnets6 Technological Quadrupoles Two mechanical designs are under development Same coils / Aperture = 90 mm / Gradient > 200 T/m @ 4.2K 2 layers Filler Keys 4 pads Bladder Yoke Aluminum shell TQC: using collars Collar laminations from LHC-IR quads 1 st time applied to Nb 3 Sn coils TQS: using Al-shell Pre-loaded by bladders and keys 1 st time applied to shell-type coils LBNL: concept, design, development, coils co-fabric., assembly & test FNAL: concept, design, development, coils co-fabric., assembly & test FNAL: coils co-fabric, test at 1.9K LBNL: coils co-fabric

7. All Exp. Meeting - 08 Oct 07Michael Lamm on LARP Magnets7 Recent TQ Test Results at Fermilab TQE02: Build a TQC magnet with TQS02 coils Direct comparison of mechanical structures To be tested early Oct (this week!) TQC01b training history TQC01b (Collar structure): Re-assembly of TQC01 with 2 TQS coils 85% ssl at 4.5 K 89% at 1.9 K Reached G = 200 T/m  Improvement over TQC01 in understanding and process control TQS02 (Shell Structure): with next generation RRP 54/61 conductor, assembled at LBNL reached ~215 T/m at 4.5 K, little improvement at 1.9K TQS02a training history 4.5K 1.9K 4.5K

8. All Exp. Meeting - 08 Oct 07Michael Lamm on LARP Magnets8 Plan for Length Scale-Up LENGTH SCALE-UP CHALLENGE: No Nb 3 Sn accelerator magnet longer than 1m has ever been built LARP should make a successful 4m long quadrupole by end of 09 Design Inputs to LQ: TQ results and design studies Long mirror 2 m/4 m Nb3sn Cos (  ) Dipole with COLLAR structure Long race track 4 m Nb3Sn Racetrack coil with SHELL Structure Scale up quad (LQ) will be a 4 meter longer version of the TQ with TQS, TQC or hybrid structure

9. All Exp. Meeting - 08 Oct 07Michael Lamm on LARP Magnets9 LARP Long Racetrack The goals of the Long Racetrack (LR): fabricate and test long Nb 3 Sn racetrack coils test an Al-shell-based supporting structure (preloaded using bladders and keys) From 0.3 m to 3.6 m Reported in Sept 7, 2007 Fermilab Today Results: - I q > 90% ssl LBNL Designed BNL Built/tested

10. All Exp. Meeting - 08 Oct 07Michael Lamm on LARP Magnets10 FNAL Long Mirror This magnet is a base program contribution in support of LARP FNAL “Mirror magnet” is a Nb3Sn cos(  ) dipole where a coil is substituted by iron blocks. Long cos(  ) coils fabrication/reaction and collar mechanics prior to LQ Front view of mirror magnet SSL Successful 2m mirror magnet test in May 2007 4m mirror magnet will be tested in November LM02 quench history at 4.5K compared with 1m model

11. All Exp. Meeting - 08 Oct 07Michael Lamm on LARP Magnets11 LQ Status/Future Plans We are developing a plan whose goal is to produce 2 4- meter long LQ’s by the end of CY 2009 Program leader for LQ has been chosen (Giorgio Ambrosio) Program will involve all three participating LARP Magnet Labs Major issue to be decided is the mechanical structure There will be an external review of the LQ program in late November

12. All Exp. Meeting - 08 Oct 07Michael Lamm on LARP Magnets12 LARP Magnet Status 1)Several TQ Magnets have been built. All of them work well. Performance improves with successive rebuilt due to increased understand of mechanics and coil fabrication. 2)Scaleup to 4 meters is underway. 4 meter long racetrack and 2 meter long mirror dipole (4 meter test soon) LQ plan for 4 meter long cos(  ) underway 3)Beyond LQ several LARP activities toward final goal of Nb3Sn accelerator magnets (local leaders) 1)Conductor Studies for higher Jc better conductor stability (Barzi) 2)Join AP/Magnet IR studies (Zlobin) 3)HQ quad model program (project leaders at LBNL but with contributions from Fermilab on magnetic design for e.g.) 4)1.9K Test facility and instrumentation upgrades