HHH From Pipetron to LER history of a

HHH From Pipetron to LER: history of a brilliant idea and goal of this workshop Lucio Rossi CERN L. Rossi – LER workshop CARE-HHH workshop on LER CERN -11 October 2006

When this started… 2 L. Rossi – LER workshop HHH

…when I met Peter Limon… • This paper reported how US HEP was emerging from SSC collapse. • A “RLHC” was discussed at the ‘ 96 Snowmass meeting, opening a cycle that was closed in the 2001 Snowmass meeting where VLHC was put in second priority wrt ILC 3 L. Rossi – LER workshop HHH

… Peter presented a new type of magnet • Invented by Bill Foster • 50 Te. V beam with 1. 8 T in a 650 km long tunnel 4 L. Rossi – LER workshop HHH

A parameter table and a few key issue were provided 5 L. Rossi – LER workshop HHH

From VLHC … back to LHC HHH • VLHC study were stopped in 2001 • However the ongoing pipetron magnet demonstrator was allowed to continue in Fermilab (2 m long magnet with ancillaries) • Talks about using it as LHC injector started as early as 2001 -02 among Bill, Peter and myself. The most sensible proposal was to drill a hole in the detectors to solve the problem of the bypass… • End 2002 - beginning 2003 all these ideas for the LHC found a frame… 6 L. Rossi – LER workshop

HHH European Steering Group for Accelerator R&D 7 L. Rossi – LER workshop

CARE Coordinated Accelerator Research in Europe The objective of CARE is to carry Accelerator Research by integrating the European resources Submitted on April 15 th , at 11: 35 8 L. Rossi – LER workshop HHH

Result of the evaluation process CARE ranked at the. Web 14 th position out of 154 project (5 th rank of the 58 IA) site: http: //esgard. lal. in 2 p 3. fr CARE is accepted Userid: esgard , password: hep 65% ~5 M€ 30% ~. 7 M€ 90% 3. 6 M€ 30% ~0. 3 M€ 30% ~0. 45 M€ 9 HHH 25% ~1 M€ 90% 3. 6 M€ CARE is recommended for funding at the maximum level of 15. 2 M€ (i. e. 52% of initial request) in the Evaluation Summary Report (ESR) L. Rossi – LER workshop

Scope of the WP 1 HHH • 5 critical study and R&D tasks identified based on present state-of-the-art in magnet and accelerator technology : – AMT-1 - Stability and Quench Limit of LHC at Ultimate Field and for LHC Upgrades (L+E) – AMT-2 - Pulsed Magnets (for an SPS Upgrade) (L+E) – AMT-3 - Magnets for a LE Ring in the LHC Tunnel (E) – AMT-4 - High Field Magnet Design (L+E) – AMT-5 - Optimisation of the overall Cost of the Magnet System for a High Energy-High Intensity Hadron Collider – Task on synchrotron radiation handling dropped 10 L. Rossi – LER workshop

HHH And SPS to LHC transfer line? • Two accelerators will shut down, presumably, after LHC commissioning: • HERA and Te. Vatron: can we made the best use of their magnets? Especially the good B>5 T HERA magnets!! • Do they adapt? (Fermilab’s are shorter) 11 L. Rossi – LER workshop KHM has looked at : extremely difficult P. Limon is supposed to assess feasibility and cost

This money and energy for what ? - VII: INJ for LHC 2 • Pipetron! The cheap Sc magnet for 2 T • Iron excited by a transmission line of HTS (LN!!!) 12 L. Rossi – LER workshop HHH

Pipetron - Cont. 2 • • 13 HHH Invented in Fermilab by W. Foster around 1995 -96 Strong push to arrive to a model then put aside by the lab after the decision of 2001 to postpone VLHC. Test of a 1 m long model in 2004 Cable might be done in Mb. B 2 !! As well. L. Rossi – LER workshop Courtesy of H. Piekarz (Fermilab)

HHH LEP LHC 14 L. Rossi – LER workshop Merci a M. Muttoni

HHH New Low Energy ring 15 L. Rossi – LER workshop Space LEP

What we have learnt so far • This project was born because a new magnet design was available and somebody was trying to use it. • Although this might become an enabling technology, the real problem proved to be not in the ring magnets but elsewhere • Magnets are feasible but what about the collider feasibility? 16 L. Rossi – LER workshop HHH

Rational for an LHC injector • The LHC main dipoles have sizable (dynamic) multipoles at the injection field. • The LHC spends 20 mins at the injection plateau while being filled by the SPS • Bunch intensity and emittance are limited by these • These limitations can be taken out by injecting at a higher energy (x 2) and in a shorter time (< 1 s) • An injector ring would also allow for RF gymnastics like bunch coalescing to overcome the intensity limitations of the injector chain 17 L. Rossi – LER workshop HHH

Hot Questions • Feasibility of the various schemes near the detector – Bypass tunnel – LHC detector beam pipe – Through detectors (is this really unacceptable? ) • Safety and reliability • Any show stopper (impedance? , lattice? , space available in the ring? ) • Low magnet cost. Does this really translate in a low cost ring? 18 L. Rossi – LER workshop HHH

Main Goal • To assess if it is technically worth to explore the idea more deeply. • To assess if it might contribute significantly to the LHC luminosity, (preparing the ground for an LHC energy upgrade is good but is more far into the future • Today the comparison with competing schemes (SPS upgrade) is premature: The LER has to prove it is useful and possible before trying to prove that is better than… 19 L. Rossi – LER workshop HHH