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B Factory Resumes Operations
By Matthew Early Wright
After a
nearly five month shutdown, the B Factory experiment is back on-line and
gathering data in earnest. The BABAR detector produced its first
collisions since the restart on April 16.
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Cross-sectional view of the
BABAR
detector, showing one of the
first Run 5 examples of an e+e- collision producing multiple
long-lived charged and neutral hadrons in the inner parts of the
detector. Hits from traversing charged particles are visible in
the silicon vertex tracker and drift chamber, showing curved
trajectories in the solenoidal magnetic field.
(Image courtesy of David MacFarlane) |
“After more than two weeks of collisions, PEP-II has over 65 percent of
its former peak luminosity,” said John Seeman (AD), head of the
Accelerator Department. “This has been the best beam turn-on so far, and
we are very pleased. The support personnel and maintenance staff have
done an excellent job.”
Director Jonathan
Dorfan suspended operations of all accelerators at the Laboratory last
October, when an electrical accident left a contract electrician
seriously injured. The Lab has since been working to address safety
concerns raised by the DOE’s review board.
Dorfan assembled
validation teams to ensure the safe restart of operations for the Lab’s
major accelerator facilities. SPEAR3 completed its validation in January
and was operational soon thereafter. The B Factory’s validation team
approved the restart on Thursday, March 24. Since then, the staff has
been working hard to restore operations after the lengthy shutdown.
“I don’t remember the
last time the accelerator complex was off for this long,” said David
MacFarlane, spokesman for BABAR. “Everyone involved with the B Factory
is excited to resume data collection.” This excitement is tempered by a
renewed commitment to safety at the Lab.
According to Seeman,
the B Factory staff has updated key protocols and made several hardware
upgrades to enhance safety. “We are thrilled to be up and running
safely, starting to provide data to the BABAR detector,” he added.
The B Factory is
addressing some of the most perplexing questions in physics. Stated
broadly, the experiment hopes to answer why matter won out over
antimatter in the first few milliseconds following the Big Bang.
But the B Factory is
not the only experiment pursuing this goal. The Belle detector, at KEK
in Japan, has been collecting data while the BABAR detector sat idle.
“We’ve been watching
the competition collect data steadily over the last five months,”
MacFarlane said. “Now that the B Factory is running again, people are
feeling much more upbeat.”
MacFarlane said recent
upgrades will eventually allow the B Factory to collect data 40 percent
faster than before. At this rate, the team should be able to double the
total data set by next summer.
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