Fermilab-designed beam position monitors go to KEK

Members of the beam position monitoring collaboration for KEK's Accelerator Test Facility. First row from left: Brian Fellenz, Andrea Saewert, Manfred Wendt and Eliana Gianfelice. Second row from left: Duane Voy, Dehong Zhang, Charlie Briegel, John Van Bogaert, Alexey Semenov and Nathan Eddy. Not pictured: Peter Prieto.

Last May, in only two weeks' time, a team of Accelerator Division Instrumentation Department employees installed, powered, debugged and started up a brand new, home-made beam position monitoring system at KEK's Accelerator Test Facility. It worked flawlessly.

"I'm very happy with the BPM's operational performance just after installation," said KEK physicist Nobuhiro Terunuma. "It was a result of the professional work by our Fermilab colleagues."

The development of ATF's new beam position monitoring system began in 2007, when Fermilab scientists helped upgrade 20 of 96 damping ring BPMs with Echotek digitizer boards, which process the beam signals. It later became clear that if KEK continued to purchase commercially available products, upgrading all 96 BPMs would be cost-prohibitive. So members of Fermilab's Instrumentation Department, led by Manfred Wendt, set out to design from scratch a new board - and a whole new system to go with it.

Commissioning a Fermilab original gave KEK the advantages of a customizable BPM system without breaking the bank.

"A commercial system may or may not be adaptable to your specific needs," said AD electrical engineer Peter Prieto, who oversaw the system's implementation. "We have experience in engineering the solution, so we can really tailor-make it to a specific machine."

Beam position monitors give accelerator scientists the data they need to characterize the beam's orbit and related information. An optimal beam trajectory should be perfectly centered inside the quadrupoles, the magnets that focus beam particles. That "golden" beam orbit will provide the ultimate low emittance, an indicator of good beam quality.

The Fermilab-built system, using completely rewritten software and re-engineered firmware and hardware, provides KEK with ultra-high-resolution BPMs needed to optimize and confirm low-emittance beams. It also self-calibrates the BPMs on the fly. The digitizers are flexible enough to work in different system configurations, so they can be used in almost any accelerator.

"We can make the system do just about anything they can dream up," said Fermilab physicist Nathan Eddy.

"The success of this collaboration is due to the good team spirit of our instrumentation experts, their enthusiasm and their willingness to work far beyond what is typically required," Wendt said.

-- Leah Hesla

KEK collaborators Nobuhiro Terunuma and Junji Urakawa sit next to a display of the first ATF beam orbit measured by the Fermilab-designed BPM system.

Citizen science: People power

From Nature News, Aug. 3, 2010

Networks of human minds are taking citizen science to a new level, reports Eric Hand.

The whole thing began by accident, says David Baker, a biochemist at the University of Washington in Seattle. It was 2005, and he and his colleagues had just unveiled Rosetta@home - one of those distributed-computing projects in which volunteers download a small piece of software and let their home computers do some extracurricular work when the machines would otherwise be idle. The downloaded program was devoted to the notoriously difficult problem of protein folding: determining how a linear chain of amino acids curls up into a three-dimensional shape that minimizes the internal stresses and strains - presumably the protein's natural shape. If the users wanted, they could watch on a screen saver as their computer methodically tugged and twisted the protein in search of a more favourable configuration.

Thousands of people were signing up for Rosetta@home, says Baker, which was gratifying, but not entirely surprising; this kind of digital citizen science had become almost routine by then. It was first popularized in 1999 by the SETI@home project at the University of California, Berkeley (UCB), which harnessed volunteers' computers to sift through radio telescope data in search of alien signals. And in 2002, UCB engineers had released a generalized version of the software known as the Berkeley Open Infrastructure for Network Computing (BOINC). By 2005, there were dozens of active BOINC projects - Rosetta@home among them - and hundreds of thousands of users worldwide.

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