26 January 2006
Our major theme for the past six months has been to establish a basic “configuration” for the International Linear Collider. The GDE process got underway last August at Snowmass and culminated in our approval of a “strawman” configuration at a meeting in Frascati, Italy in December. That work resulted in a Baseline Configuration Document (BCD) that now is forming the starting point and the basis for our new major theme for this calendar year, which is to develop a “design and cost” for this collider concept.
The process of transitioning to this new mode began in earnest this past week at the first meeting of “GDE Area Systems Leaders” at KEK . That meeting was organized by our regional accelerator leaders, Tor Raubenheimer, Nick Walker and Kaoru Yokoya. The goal of the meeting was to give guidance (or marching orders) to the leaders of the teams who are responsible for carrying out the actual design and costing. We are now calling these design teams “Area Systems” groups. These groups have evolved from the original working groups, who created the BCD. The six groups are e- source, e+ source, damping rings, ring to main linac, main linac and beam delivery systems. The names are changed to represent the fact that the groups now have decidedly more emphasis on engineering and costing. In doing the design and costing, these groups will be supported by other groups in a matrix like structure that cross these different areas of the machine -- either technical systems like vacuum systems, magnet systems, instrumentation, etc., or global systems like controls, conventional facilities and reliability. These pieces all have to work together in a way that produces a coherent design with reliable costing.
All of this sounds rather complicated, but what I have just described is only a way to break down the problem of doing the design into its pieces. At the KEK meeting, the charges for the area systems were discussed in the context of a timeline that will produce a Reference Design Report (RDR) this calendar year. This report is to be a technical document describing the collider with a construction cost and schedule. To achieve this goal, we delineated a set of major milestones for the GDE meetings in Bangalore in March and in Vancouver in July.
Within all this seemingly cumbersome, but essential, discussion of organizational issues at KEK (see accompanying meeting summary by Peter Garbincius), were some very lively discussions of technical issues. One discussion that particularly stood out at the KEK meeting involved a presentation of timing issues for the damping rings by Andy Wolski, and in particular, the allowed flexibility for different fill patterns depending on the relationship between the diameter of the damping ring and other critical lengths in the collider. This may sound like an academic issue, but in fact it reflects itself in the final operational flexibility of the collider, in terms of allowing different bunch spacing and fill patterns while maintaining beam collisions.
I believe that, upon reflection, we will mark the KEK meeting as the beginning of this new and challenging phase of our work within the GDE -- one where we are concentrating on developing a design and costing for the reference design, and especially one with cost consciousness built into every corner of our process. Our goals and time scales are very ambitious, but if we can capture the momentum that was developed at KEK we will quickly be on our way.