• G. Ambrosio, G. Chlachidze, M.J. Lamm, A. Nobrega, E. Prebys
  Fermilab, Batavia
• S. Caspi, H. Felice, P. Ferracin, G.L. Sabbi
  LBNL, Berkeley, California
• T.W. Markiewicz
  SLAC, Menlo Park, California
• J. Schmalzle, P. Wanderer
  BNL, Upton, Long Island, New York

The first Nb₃Sn Long Quadrupole (LQS01) designed and fabricated by the US LHC Accelerator Research Program (LARP) reached its target gradient of 200 T/m during the first test. LQS01 is a 90 mm aperture, 4 meter long quadrupole with Nb₃Sn coils made of RRP 54/61 strand (by Oxford Superconducting Technology). The two-layer coil design is based on the LARP 1m Technological Quadrupoles (TQC and TQS). The mechanical structure is based on the TQS structure implementing an aluminum shell preloaded by using bladders and keys. In 2005 LARP, in agreement with DOE and CERN, set the goal of reaching 200 T/m in a long Nb₃Sn quadrupole by the end of 2009. Achieving this goal in the first test shows the maturity reached by the Nb₃Sn technology for possible application to particle accelerators. Additional tests have been performed aiming at reproducing the performance of the most recent TQ models in order to demonstrate that there are no significant scale-up issues with this technology.

Slides

• S. Caspi, D.W. Cheng, D.R. Dietderich, H. Felice, P. Ferracin, R.R. Hafalia, J.M. Joseph, J. Lizarazo, G.L. Sabbi, X. Wang
  LBNL, Berkeley, California
• G. Ambrosio, R. Bossert, A.V. Zlobin
  Fermilab, Batavia
• M. Anerella, A.K. Ghosh, J. Schmalzle, P. Wanderer
  BNL, Upton, Long Island, New York

Advanced superconductors such as Nb₃Sn are being considered for future magnet upgrades of the Large Hadron Collider (LHC) at CERN. The US LHC Accelerator Research Program (LARP) has developed a large bore (120mm) Nb₃Sn IR quadrupole (HQ) capable of reaching 15 T at its conductor and a gradients of 199T/m at 4.4K and 219T/m at 1.9K. HQ is addressing coil alignment and accelerator field quality in a shell-based mechanical structure. In this paper we summarize the fabrication, assembly and initial test results of the 1 m long two-layer magnet.

• B. Parker, M. Anerella, J. Escallier, P. He, A.K. Jain, A. Marone, P. Wanderer, K.-C. Wu
  BNL, Upton, Long Island, New York
• P. Bambade
  LAL, Orsay
• B. Bolzon, A. Jeremie
  IN2P3-LAPP, Annecy-le-Vieux
• P.A. Coe, D. Urner
  OXFORDphysics, Oxford, Oxon
• C. Hauviller, E. Marin, R. Tomás, F. Zimmermann
  CERN, Geneva
• N. Kimura, K. Kubo, T. Kume, S. Kuroda, T. Okugi, T. Tauchi, N. Terunuma, T. Tomaru, K. Tsuchiya, J. Urakawa, A. Yamamoto
  KEK, Ibaraki
• A. Seryi, C.M. Spencer, G.R. White
  SLAC, Menlo Park, California

The KEK ATF2 facility, with a well instrumented beam line and Final Focus (FF), is a proving ground for linear collider (LC) technology to demonstrate the extreme beam demagnification and spot stability needed for a LC FF*. ATF2 uses water cooled magnets but the baseline ILC calls for a superconducting FF**. Thus we plan to replace some ATF2 FF magnets with superconducting ones made via direct wind construction as planned for the ILC. With no cryogenic supply at ATF2, we look to cool magnets and current leads with a few cryocoolers. ATF2 FF coil winding is underway at BNL and production warm magnetic measurements indicate good field quality. Having FF magnets with larger aperture and better field quality than present FF might allow reducing the beta function at the FF for study of focusing regimes relevant to CLIC. Our ATF2 magnet cryostat will have laser view ports for cold mass movement measurement and FF support and stabilization requirements under study. We plan to make stability measurements at BNL and KEK to relate ATF2 FF magnet performance to that of a full length ILC R&D prototype at BNL. We want to be able to predict LC FF performance with confidence.

* ATF2 proposal, volumes 1 and 2 at http://lcdev.kek.jp/ILC-AsiaWG/WG4notes/atf2/proposal/index.html
** International Linear Collider Reference Design Report, ILC-REPORT-2007-001, August 2007.