Director's Corner
 

16 June 2005

Barry Barish

Last week in my first Director's Corner I primarily discussed this interim webpage and our plans to use it as a regular way of informing the community about what is going on with the GDE. I also discussed the importance of the Snowmass workshop in August, where we will take the first decisions on the configuration that we will use as the baseline for a conceptual design for the ILC. I will say more on Snowmass in later columns, but first I would like to put into context where we are and what we will be doing at that workshop.To do that, I will spend the next few Director's Corners giving my personal perspectives on where we are, how we got here and where we will go next.

Let's begin by going back a decade or so, to see how far we have come. At that time, for many of us the idea of proposing a 1 TeV scale linear collider seemed like a pipe dream. To get to such a high energy scale for e+e- collisions, a circular machine (like LEP) would no longer be practical due to the large synchrotron radiation for electrons in a circular orbit. Thus, the only solution was to try to develop the technologies for building a linear machine. This was a particularly challenging task because of the very large gradient needed to reach the desired energy while keeping the machine to a realistic length. In addition, because the beams only cross each other once, they need to be very bright, focused to an extremely small spot and directed accurately at each other, in order to have a reasonable probability of making collisions. The only example of such a machine was the Stanford Linear Collider, which provided a crucial proof of concept, but it was a very long extrapolation to the parameters contemplated for the linear collider.

I must admit that at that time I was among many doubters in our community as to whether such a machine was possible. Yet, by the beginning of the new millennium, most of the key issues had been addressed, and many of the concepts necessary to undertake construction of a linear collider had been demonstrated. Not only that, this had been done for two different technical approaches for the main linac, one using superconducting rf (the so-called cold technology) and the other using copper structures at room temperature (the so-called warm technology). The advantages and disadvantages of these two technologies made it difficult to decide which was the right technology to pursue, and a long and challenging period of sorting out that decision followed.

I will discuss the process of making the difficult technical decision between warm and cold technologies in a future message, but today I would like to pay tribute to the R&D effort that proved the ILC concept. Extensive accelerator R&D had been pursued on an international basis for over a decade. The investment led both to a proof of concept for the ILC and to many technical advances that will have applications far beyond this application. There are always many uncertainties in pursuing R&D programs that might lead to the next generation of instruments for our science, yet this type of investment and the advances of technology that result are essential if we are to continue addressing the key questions in our field. In my opinion, we have far too little appreciation and make far too little investment in developing the future technologies and instruments that we depend on to move our science forward. The success of the R&D program for the linear collider is a very important and visible example of how completely the foundation for the future depends on the results of a successful R&D effort.

I want to end today by announcing a very important early development for the GDE. Brian Foster has accepted my offer to become the European Regional Director for the GDE. He, Gerry Dugan for North America, and Fumihiko Takasaki for Asia now make up the Regional Directorate. An important aspect of the way the GDE effort is structured is that it does not directly control resources. Rather, resources will continue to be distributed regionally to the laboratories and universities by the various funding agencies. This presents a big challenge for centrally directing a global project and the Regional Directors are key to the development of programs and priorities within each region that match the GDE goals. We are very fortunate to have three such talented and respected Regional Directors, and I look forward to working very closely with all three of them as we develop our program.