David Quarrie Taking Two-Year Assignment to Manage ATLAS Software Project

David Quarrie, head of NERSC's High Energy and Nuclear Physics Computing Group, has accepted a two-year appointment as software project leader within the reorganized computing organization for the ATLAS experiment in Geneva, Switzerland. The ATLAS particle detector, scheduled to begin generating massive amounts of data in 2007, is part of the Large Hadron Collider under construction at CERN, the European Organization for Nuclear Research, the world's largest particle physics center.

For the past three years, Quarrie has served as chief software architect for ATLAS, with responsibility for developing the core software. In his new position, he will be responsible for reaching a key milestone -- producing the computing technical design report. The report will be a detailed description of the software infrastructure needed for collecting, transferring, storing and analyzing data from ATLAS. "This report will let us know exactly how we're doing leading up to turning on the experiment," Quarrie said. "It will be a major milestone to taking the first data."

Managing this project, Quarrie will encounter issues similar to those involved in creating the software framework -- he is responsible for a large project but does not have full control of the resources, which are distributed across many institutes and funding agencies worldwide.

"The primary difficulty is in getting a large, geographically dispersed group of people to work efficiently and productively and fill the holes in the project, without duplicating each other's efforts," Quarrie said. "Many of the issues are more sociological rather than technical. I think that's one of the more interesting things about this job."

Currently, ATLAS is a collaboration involving about 1,800 researchers from 150 institutions in 34 countries. Many of those institutions have software developers involved in the project, but persuading them to work on the nuts-and-bolts aspects, rather than the more interesting physics problems, is a challenge, especially as many of them are volunteering their time for the project. The ATLAS project recently reorganized its computing structure to clarify the areas of responsibility and authority within the computing organization, and particularly strengthens the authority of the software leader relative to those of the chief architect. As software project leader, Quarrie will become a member of the Computing Oversight Board and will sit on the overall Experiment Board, the main governing body of the project.

The technical challenges come from the large, complex nature of the collaborative experiments, David said. The ATLAS program is scheduled to begin conducting experiments in the year 2007 and is the next-generation data-intensive computing project in high-energy physics, similar to the experiments at Brookhaven, Fermilab and SLAC, but on a larger scale. While the STAR (Solenoidal Tracker at RHIC) will generate about 250 terabytes of data annually, ATLAS will yield up to 1.5 petabytes per year for 10 years.

Along the way to the major milestones are a number of computing "stepping stones," Quarrie said. These consist of a series of "data challenges," in which scientists will generate simulated data and feed it through the computing infrastructure to measure the system's ability to handle data once the experiments begin.

The five-story-high, 7,000-ton ATLAS detector is designed primarily to understand the origin of particle masses. It is expected to find the Higgs boson (or family of bosons) if it exists and to fully explore many other new possibilities including the predicted massive "sparticles" of supersymmetry theory.

For the next five months, Quarrie will be spending three weeks each month at CERN. In July his wife, Avril, will join him and they will take up full-time residency in the region. Quarrie's now sorting out such issues as health insurance and renting out his home here while taking on the new job and finding a place to live overseas.

But it's not like exploring a strange territory -- he's been spending about a third of his time at CERN for the past two years -- and earned his Ph. D. on an experiment at the center in 1974.

In his absence, Craig Tull (who recently spent a year himself working on ATLAS software at CERN) will be acting group lead.

Quarrie figures he was asked to take on the assignment due to his years of expertise. Trained as a physicist, Quarrie has been involved in high-energy physics computing since 1970 and has worked at Berkeley Lab since 1993. While at LBNL, he has served as the software project engineer for BaBar at SLAC. Members of his group hold similar jobs with the ICE CUBE and SNAP projects.

"I think it's a feather in our cap for the Lab to be recognized for its depth and proven record in this area -- it's clearly one of our institutional strengths," Quarrie said.