1. 1 Comments concerning DESY and TESLA Albrecht Wagner Comments for the 5th meeting of the ITRP at Caltech 28 June 2004 DESY and the LC What could DESY contribute to a LC?

2. 2 Dedication of DESY to the LC DESY is firmly committed to a strong participation in a global Linear Collider, independent of the recommended technology : In the five year programme of DESY 2005-2009 (in the framework of our new funding scheme) the participation in a global Linear Collider will be one of the core activities in particle physics at DESY, especially after the end of HERA. The reviewers strongly endorsed this programme, as did the DESY Scientific Council. As a consequence DESY will receive a budget for the LC (amount to be decided by the Helmholtz Association in fall). This strategy is in accordance with the Research Policy Requirements issued by the Federal Government for DESY.

3. 3 Next Steps towards the LC DESY will submit a bid to host the Central Team of the GDI. DESY, as coordinator together with CERN, and European institutes and universities have submitted a proposal for a Linear Collider Design Study within the 6 th framework programme of the EU. The LC Design Study was ranked in first position among 130 proposal, together with the XFEL Design Study (focusing among other things on cryomodule technology) Scope: Technology independent aspects Key comments of the evaluations are:

4. 4 Overall Remarks EUROTeV This is an outstanding proposal, complete and compelling in every regard. It will prepare for major European participation and leadership in the most technically challenging accelerator ever built. The tasks are very well organised and the complementarity of the participants is fully exploited. Furthermore the anticipated scientific productivity of this machine is as high as any infrastructure of comparable scale in any field. The budgetary needs for this project are significant but justified.

5. 5 Special Remark EUROTeV The choice of the main linac technology by the International Technology Review Panel (ITRP), to be made shortly, will play a determining role in the prioritisation and exact technical description of the eight Work Packages. It should be emphasized also that this proposal should only be supported insofar as the EUROTeV collaboration is firmly committed to support and work within the framework of the international process for selection of the technology, leading to the construction of the ILC at the earliest possible time. EUROTeV will supply 100 FTEs over 3 years across 22 institutes, 50% from EU spending ~30 MEuro (of which 9 MEuro from EU funds)

6. 6 General Comments Independent of choice of technology Detailed planning / implementation must be made by an International Collaboration of Equal Partners –responsibility of GDI Exact details of such planning rely on available funds and resources of participating laboratories, and the World political stage

7. 7 DESY Actions if Technology Choice is COLD Actions will mostly be specific to LINAC technology Goals: –Participation in the implementation / construction of one or more SRF Module Test Facilities (wherever they are built) for testing LC-type prototype cryomodules –This facility should support the rapid transition from the TTF Cryomodule (CM)  LC CM –Participation in large scale industrialisation in all three world regions (in Europe this process was begun with the TESLA TDR, and its continuation is now funded through the EU FEL Design Study and the XFEL project)

8. 8 TESLA Collaboration Role as part of the GDI DESY (TESLA collaboration) role: –A large part of XFEL preparatory work & R&D is directly applicable (transferable) to LC industrialisation cavity production Klystrons & RF distribution LLRF, tuners etc. cryoplants reliability –~30% TTF-II beam time available for LC work Note: 100% of time will provide invaluable experience for a future cold LC, especially the ~40% stable operation of FEL users Will integrate interested LC collaborators in this process

9. 9 Cryomodule Work LC specific work: –Work on high gradient programme continues, main emphasis will be on yield (= quality control), procedures are established –CM with >35MV/m construction & test This will be done by TESLA collaboration over next 1-2 years –design of LC CM (quad position, length etc.) will require additional efforts Engineering only (not fundamental R&D) can be ramped up quickly connection with CARE SCRF Joint Research Activity

10. 10 Superconducting RF (SRF) CARE is funded at the level of 15.2 M€ over 5 years ~.7M€ ~0.3M€ ~0.45M€ 3.6M€ ~1M€ ~5M€ EU Funding - CARE

11. 11 Other Actions TESLA collaboration can supply TTF-like CM with 35MV/m cavities with current infrastructure/manpower/expertise (some additional resources are needed) –in parallel / synergy with XFEL preparation –to be shipped to new LC test facility In parallel (ramped up), R&D (within GDI context) on LC CM design In parallel work on large scale industrialisation –with industry (XFEL will play an important role in Europe) –with collaborating labs (US collaboration and Japan)

12. 12 DESY Actions if Technology Choice is WARM There is no detailed plan yet of what DESY would contribute to the design and construction of a warm LC. Some possible aspects of the work are defined within the scope of the EUROTeV proposal WG1: Overall Coordination * WG2:Beam Delivery System WG3:Damping Rings WG4:Polarised Positron Source WG5:Diagnostics WG6:Beam Dynamics Simulations WG7:Metrology & Stabilisation WG8:Controls (GAN) Participation Coordinating Role EUROTeV Work Packages * together with CERN