Describe the effect upon the laboratory of a) the warm vs. cold decision b) choice of site

1. Describe the effect upon the laboratory of a) the warm vs. cold decision b) choice of site Norbert Holtkamp 6/29/2004 Disclaimer: This assessment is not based on physics, engineering or other sciences. It is largely a personal assessment taking into account what the lab directors and other proponents have said. It is a summary of what became obvious, and an attempt to provide information to judge which technology choice would do the least harm across the board.

2. LC would directly profit from XFEL 10% prototype experience with 180FTE’s working on this technology (see table) Official: More resources are necessary (but where do they come from since experts needed) Timescale fits with XFEL schedule since LC will take longer. Unofficial: Cold decision will drain resources much needed for XFEL. (Threat to DESY) Accel Div can not support both activities successfully ►can see efffect: LC group has 2 members at DESY Boost morale of HEP at DESY since there is no HEP future project aft ’07. Leverage for DESY to reconsider recommendation from German gov. Integrates well with the FRP6 programs under way from European union on SRF (CARE) DESY: Impact on the Laboratory: Cold

3. DESY: Impact on the Laboratory: warm • More resources are needed in this case too. • DESY Accel Div contribution is minimized and focused on XFEL • Detector and physics effort will be main contribution and the remaining HEP branch @ DESY after ’07. • Integrates well with the FRP6 program from EU for the Detector and physics part (Eurotev only). • Collaboration with CERN will be more favorable (E. Elsen, coordinator for Eurotev at DESY)

4. DESY as a site • Makes sense only if “cold” because of ground motion limitations. Warm machine will not work at DESY. • Planning for 500/800 GeV is done. Probably the fastest track to LC in that energy range. • “planfeststellungsverfahren” is done. • Engineering layout done • Environmental impact studies done • Inter-government agreement between states in Germany signed • BUT: German government has chosen N O T to bid for site @ Hamburg for the time being. … so it’s a mute point until this can be reversed. There is no plan for accelerator based HEP after ‘07 in Germany at this point. • Cold and DESY is little risk for successful construction • Warm and DESY, no way; but CERN would be more positive • Warm and other site means little support from DESY, but CERN would be more positive. • Cold and other site is helpful since 10% prototype is underway and technology can be transferred with much to offer from DESY.

5. KEK: Impact on the Laboratory • Warm or cold, the ITER decision and JPARC and its recent extensions will determine to a much larger extent how much and how deeply Japan can get involved in a LC. • JPARC schedule is consistent with more conservative LC schedule, but inconsistent with the “communities plan” (Totsuka san: “..might loose support for LC if decision is not soon”(2009) • As other projects roll off, it is intended to utilize these resources for LC, if LC comes in time.

6. KEK: Impact on the Laboratory: Warm • Would spark enthusiasm within KEK (and SLAC), but not so many other places. • KEK would have to do much of the remaining technical R&D (or SLAC), since there is no other labs with expertise in warm x-band rf. • Aligns industrialization effort with technology choice. Right now almost only x-band technology is transferred (apart from klystron for TESLA). LC Forum also supports warm. • KEK would keep the close tie to SLAC. • CERN could be attracted more easy. • Much of the expertise in Korea and China is in warm technology and can be utilized. • The conflict between c-band and x-band will remain. • Pretty much business like usual.

7. KEK: Impact on the Laboratory: cold • Lab management will have difficulties to support this decision • Justification to government agency for supporting warm for >10y would have to be made. • Significant manpower would have to move from x-band technology to cold. Also true for much of the infrastructure bought at KEK (see structures). • KEK would have to “redefine its position within the cold LC community rather than with SLAC and the continued focus on warm. • Totsuka san would have to do a lot of convincing to have people move to a cold LC rather then on something else in HEP (muon collider, high intensity proton beams etc)

8. KEK: Impact on the Laboratory: Site • Site decision is very important to Japanese HEP community. Probably even more so then technology. ACFA see LC as next big HEP project and the Asian region as its natural location. • An off shore LC would certainly have Japanese HEP look very soon for other opportunities in Japan and probably attract a large workforce and funding, which turns it away from the LC. • ASIA/ KEK would have a fully international HEP Laboratory • KEK itself as a site is impossible, which is recognized by everybody. • Technical possible to build cold or warm under Japanese ground conditions, but locations might be remote.

9. SLAC: Impact on the Laboratory • Independent of technology, SLAC has the majority of the expertise to operate a LC. This is a very different situation the in e+e- storage rings or other colliders. • This is good since that leads to a very professional approach • It is bad since man y decision are based on the specific SLAC experience • SLAC/J.Dorfan is the only director that made a convincing argument that the lab wants to be involved in any case to pretty much the same extent but may be with different focal points.

10. SLAC: Impact on the Laboratory: Warm • Would spark enthusiasm within SLAC (and KEK), but not so many other places. • It would fuel SLAC’s arrogance of being right after all and it would show. • All available expertise would be brought to work immediately with a fast track to realization (provided there is no more technology hick ups during the coming R&D) • SLAC would have to do much of the remaining technical R&D (or KEK), since there is no other labs with this expertise. A lot of R&D money would poor into SLAC for that reason(, but not into other places). • SLAC is more in a leadership position than in one of collaboration between equal partners. • Overall: Things would pretty much go like they have been over the last 10 years.

11. SLAC: Impact on the Laboratory: Cold • It would show that for whatever reason ITRP disregards the proposal by the two strongest LC proponents to use their preferred technology. • Cold is a difficult “sell” at SLAC and people can not be forced to work on it. It will need force to “push” this at SLAC. • Would lead to an attempt to built a small scale LC on the campus with very high gradient rf @ 300 GeV. • It would force SLAC into a “equal partnership” with other labs that have expertise in this area. • It would have an adverse affect on the KEK collaboration, since a decision has to be made to go with the ITRP recomm. or go with KEK to a warm LC. • It would significantly reduce warm rf R&D at SLAC (and therefore in the US). • It would SLAC leave with a vast infrastructure of no use for anything (other than B.Siemans R&D) and in position to defend why last 10 years DOE money was spend on it.

12. SLAC: Impact on the Laboratory: Site • SLAC itself as a site is impossible, which is recognized by everybody. • Technical possible to build cold or warm under CA ground conditions. • Cost of living, operations and traffic as well as environmental impact speaks against it. • A LC site close to SLAC would guarantee a larger workforce from SLAC on the LC (since nobody from SLAC wants to move out of the bay area: See Fermi experience). • A LC site close to SLAC would make it more likely to be accepted by KEK and Japanese/Asian collaborators.

13. CERN: Impact on all other Laboratories: • DESY does not represent European vision of HEP alone • CERN cold: • CERN will be very much against this, since it does not align with CERN’s technology choice. LC in Europe, threatens CERN position as lead HEP lab in Europe. Building cold a CERN, is unlikely. • CERN warm: • A warm linac will make CERN’s participation more like since it fits CERN’s goals. • A warm linac can not be build at DESY, which is good for CERN. • CERN present position is a devastating disaster for HEP community and ICFA. But unlikely to change. • It is hard to imagine how to get CERN on board for a near term LC, especially a cold one.

14. FERMI: Impact on all other Laboratories • SLAC and its user community represent the smaller fraction of HEP in the US. FERMI represents the majority, it is therefore much more important to get FERMI on board than SLAC (bluntly said). • The 40 y history of mistrust makes it very difficult to have the Fermi community agree on technology that is so dominated by SLAC and its sole expertise. • Ultimately it is more important for FERMI to be the site than to have the technology. It is a very controversial topic though since not everybody believes that a LC will be built. • FERMI needs a future for the Lab afte the Tevatron • FERMI can not be forced in position of compliance. That will create a veto for the LC. • This was underestimated by SLAC and by others. • Fermi has the most obvious site • Fermi has the vast majority of the HEP employees.

15. Summary • It’s no fun!! • It hasn’t been for more than 10 years. • Either decision will have negative impacts on a set of laboratories and individuals. • If the decision is warm, cold R&D will continues • If decision is cold warm R&D will probably only be done at CERN • The two biggest proponents and hardest working labs on LC want warm. • The larger community consensus is behind cold. • Either way, someone will loose and that’s the problem.