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From the ATLAS e-News: Trigger Time!
Kids Day Is Coming!

SLAC Today

Wednesday - June 16, 2010

From the ATLAS e-News: Trigger Time!

Racks of XPUs (Interchangeable Processing Units) that run the HLT trigger algorithms.
(Image: ATLAS eNews.)

Even though the Large Hadron Collider is currently delivering five orders of magnitude below its design luminosity, already the collision rate that this provides ATLAS is too high for the experiment to be able to store it all. With the most recent jumps in luminosity, the time has come for the High Level Trigger system to step up and get seriously involved…

"There are several stages of turning on the trigger," explains Wojtek Fedorko, who is involved with trigger operations, and affectionately describes the system as "a somewhat complicated beast."

The Level 1 Trigger—the hardware system that bases its snap decisions on the characteristics of energy clusters and energy sums in the calorimeter, or hits in the muon trigger system—has been active since the very first collisions at 900 GeV last year. It also has a number of direct inputs, including the MBTS and the forward detectors. Essentially every proton-proton collision is flagged by these detectors when charged particles from collisions hit them, and up until just a few weeks ago, every such 'minimum bias' trigger was accepted by the Level 1. At that time the calorimeter and muon triggers were a small subset of events being recorded

Read more in the ATLAS e-News...

A Kid's Day 2009 participant launches a soda bottle water rocket. (Photo by Nicholas Bock.)

Kids Day Is Coming!

The date is set: Kids Day 2010 will be held on Friday, August 20, just in time for some out-of-the classroom science before the school year starts. This year's Kids Day will include science talks, workshops, lunch and an ice cream social.

The event is open to children ages 9–16 who are sponsored by a SLAC employee or user. So bring along your son, daughter, grandchild, niece, nephew or neighbor. At last year's Kids Day, more than 250 budding scientists descended on SLAC for a day of hands-on experiments. Previous workshops have included topics as diverse as paleontology, magnetism, biology and astrophysics.

"Kids Day is a fun opportunity for kids to explore SLAC science," said director Persis Drell. "But it's also an opportunity for staff to learn about what is going on in other areas of the lab, so I encourage staff to volunteer and ask supervisors to allow participation."

Registration will be open from Monday, July 12, through Sunday, August 1. Stay tuned for future announcements!

Donations and Volunteers Needed

Workshop leaders are looking for cereal boxes and two-liter soda bottles. Please contact Richard Burgess (x4766) to donate cardboard food boxes or Natalie Cramar (x3648) to donate bottles.

Volunteers are needed to help with the Kids Day festivities. If you are interested, please contact Michelle Steger (x3011).

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