Live from Snowmass!

Nick Walker Presents GDE Summary Talk
 

After two-weeks of intense work, the GDE presented their summary talk on Friday morning. DESY physicist and GDE member Nick Walker found covering two weeks worth of work within the span of fifty minutes to be quite the challenge. “I hope that my talk will give you a feeling of the amount of work we accomplished over the last two weeks,” Walker said. “This workshop has been a great step forward in achieving the goals that we set out in the beginning.”

Walker discussed the list of top ten questions that the GDE needed to address during the workshop in order to move forward. “From these ten questions, addressing the luminosity and the gradient are probably the most important,” he said.

Global Group 1 recommended a nominal 500 GeV luminosity at 2 x 10^34 cm^-2 sec^-1. For a 500 GeV machine, based on the TESLA cavity, Global Group 1 recommends a qualified gradient of 35 megaVolts per meter and operating gradient of 31.5 MV/m with each linac 10.6 km long. For an eventual upgrade to 1 TeV, they recommend using higher gradient LL cavities having a gradient of 40 megaVolts per meter, which will add on 9.3 km to each linac. With the upgrade, the total length of the ILC would be about 40 km. “All 20,000 cavities will need a gradient of 35 megaVolts/meter, which will be quite a challenge,” Walker said. “We have a lot of work to do.”

While Walker could not cover all of the accomplishments made over the past two weeks, he emphasized the amount of progress made for the Cost and Engineering group. “They made very good progress on understanding how to do international costing,” said Walker. “I understand that they made a lot of progress in the last two weeks in putting down some guidelines and regulations.”

Between now and September, the GDE will collect and document all of the information that came out of the workshop. All recommendations will be posted on the ILC Web site. By mid-November, the GDE plans to produce a draft Baseline Configuration Design, which will also be available online. The BCD will be discussed at the next GDE meeting from December 7-10 in Frascati, Italy, where the final finishing touches will be made. “And then the real work will start,” Walker said. “We are all working very hard now, but it is nothing compared to what we have to do this next year.”

Walker concluded by thanking all of the Working Group leaders and conveners for their hard work. “The ILC project has attracted many of the best accelerator physicists and engineers from around the world. It is a great honor for me to be a part of this project,” he said. “Let us all continue to work together on this great adventure.”