Report on TESLA Collaboration Board Meeting New Members of the TESLA Collaboration: - Presentation of the Subdepartment of Particle Physics at the University of Oxford S. Cooper - Presentation of Sincrotrone Trieste C. Bocchetta Status of TESLA A. Wagner Status of TTF/VUV-FEL C. Pagani (incl. Report from the Technical Board) AOB Frascati, 28 May 2003

TESLA Project Leader At the last TESLA meeting Carlo Pagani was elected as project leader for two years, succeeding Dieter Trines Carlo took over on 1 February 2003 Now, we have to look for a new chair of the Technical Board. The search will be done by the TESLA collaboration Search Committee, chaired by J-E Augustin

A Model for a European X-FEL Laboratory European Governments European XFEL Corporation TESLA Linac Corporation Members of Coll Board will consider possible models, continue discussion in September . . . Lab 1 Lab 2 Lab n Linac Network experiments undulators Linac injector beam lines

Of Key Importance for X-FEL: TTF2 VUV FEL TTF1 will be extended to reach 1 GeV in 2003 and become a user facility in 2004 TTF1

European XFEL Laboratory time schedule 2000 m 1200 m start in 2005 ●●●●●●●●●●●●●●● complet in 2011

Technology Recommendation Aim at joint selection of one technology in 1 year. How: Gather a committee of wise persons, who use criteria to be developed by the ILCSC, to recommend a technology choice to the ILCSC. The regional steering committees will each nominate 4 persons from which the ILCSC will choose three from each list for a total of 9 wise persons. First discussion of the make-up of the committee in August. Advice in this will be widely sought from the community.

Progress on TESLA Technology Due to the XFEL DESY (and partners) will focus in preparation of collider very much on linac related issues (industrialisation, reliability, high gradient programme) First high power test of an electro-polished cavity very good result, similar to vertical test It is essential to continue the R&D on high gradient cavities -> beam tests Of top priority for technology decision

Next Steps for TESLA The focus of the work: reach the R1 milestone, as defined in the ITR report (test of one module with beam at 35 MV/m). Due to the extremely tight financial situation at DESY in 2003 this goal will not be reachable within one year. It is therefore very important to approach this goal as much as possible until spring 2004: Test as many 9-cell cavities as possible, with full power for as long as possible at their highest gradient (35 MV/m). Test with a first 9-cell cavitiy have shown very promising results. In addition it would be very good if at least one 9-cell cavity could be tested with beam (under investigation).

Laboratory for Elementary Particle Physics US-hosted Linear Collider Options: A study commissioned by the US Linear Collider Steering Group G. Dugan Laboratory for Elementary Particle Physics Cornell University Ithaca, NY 14853

Charge Membership of the USLCSG Accelerator Subcommittee: David Burke (SLAC) Gerry Dugan (Cornell) (Chairman) Dave Finley (Fermilab) Mike Harrison (BNL) Steve Holmes (Fermilab) Jay Marx (LBNL) Hasan Padamsee (Cornell) Tor Raubenheimer (SLAC) The Accelerator Subcommittee of the US Linear Collider Steering Group (USLCSG) has been charged by the USLCSG Executive Committee with the preparation of options for the siting of an international linear collider in the US. Two technology options are to be developed: a warm option, based on the design of the NLC Collaboration, and a cold option, similar to the TESLA design at DESY. Both options will meet the physics design requirements specified by the USLCSG Scope document. Both options will be developed in concert, using, as much as possible, similar approaches in technical design for similar accelerator systems, and a common approach to cost and schedule estimation methodology, and to risk/reliability assessments.

Scope of the LC - ECFA/DESY Study (Amsterdam) A cms-energy range of 91 to 500 GeV At 500 GeV instantaneous luminosity and reliability sufficient to deliver a total of some 500 fb-1 in the first 4 years of running tunnel and floorspace available for two interaction regions, at least one of them with finite crossing angle, and at least one fully functional detector both interaction regions allowing the same energy range and luminosity for e+e- collisions 80% electron polarisation capability to run e-e- experiments possibility to get to higher energies (some 750 GeV cms) without increasing cooling and RF power, i.e. with reduced luminosity at increased gradient

TESLA and the Technology Choice If the chosen technology is ‚cold‘, a major synergy will exist between the work on the X-FEL and the LC: SC technology, mass production, reliability, all RF issues (klystrons, LLRF, RF distribution and components ..) Fast orbit feed back Damping ring kicker system (X-FEL beam distribution) Beam diagnostics …. If the chosen technology is ‘warm’, a major rethinking is necessary. In this case the role of DESY (and possibly some of the TESLA partners?) will be less pronounced, due to the commitment to the X-FEL.

New SC Projects High Energy Physics TESLA 200 MHz for Neutrinos High Energy Physics TESLA Neutrino Factories and Muon Colliders Kaon Beam Separation at FNAL New TEVATRON Injector Nuclear Physics RIA EURISOL CEBAF Upgrade High Power Proton Linacs for Spallation SNS, Joint-Project, Korea, ESS ADS for Waste Transmutation New Generation Light Sources Recirculating Linacs (Energy Recovery) SASE FELs SNS

Global Linear Collider Center All (ILCSG) agree that it would be highly desirable to form a precursor to the Global Linear Collider Center: Core group to begin making an international design, based on accumulated work to date, but reexamined in a completely international context. In parallel to the work of the design group: preparation of political decision, definition of organisational structure, site analysis Aim at approval of LC around 2006/2007

Global Linear Collider Center – European Branch Many other R&D activities have been co-ordinated by the TESLA partners and others in preparation of the 6FP (-> ESGARD, CARE…) A draft proposal (‘Design Study’) for the European branch of such an international design team is presently being prepared for the EU. Meeting of interested people took place yesterday, chaired by Nick

FP6 LC Design Study Use to form core R&D group within Europe for future Global LC (GLC) Proposal must remain flexible with respect to linac technology decision (2004) Focus DS on sub-systems other than linac technology (sources, DR, BDS etc) DS will be based on existing LC net formed for CARE FP6 proposal Proposal will be drafted by ELCSC Accelerator sub-group (and coordinated by N. Walker).

Next Steps X-FEL Continuation of the R&D work for the X-FEL accelerator Formation of a planning group with all interested partners (including future users) Analysis of the present concept for the linear accelerator, as described in the TDR supplement, and the laser facility by the planning group Adaptation of the project parameters to include the findings and recommendations of the planning group Linear Collider Continuation of the high gradient programme (construction, optimisation and tests of cavities with 35 MV/m) Build-up of a European LC Design Teams as part of an international Design Team Participation in the LC working groups of ICFA and ECFA

Next Steps - 2 Establish list of work packages (already discussed by WG 1) and responsibilities to get ready for mass production of cryomodules Re-discuss during September meeting Collaboration Board endorsed these steps

Final Comments Next TESLA meeting 15-17 September 2003 in Zeuthen Many thanks to our hosts at Frascati for a very pleasant and efficiently run meeting