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In this issue:
BaBar Collaboration Meeting Starts Today
Safety Today: Ergonomics: Safe Material Handling
symmetry Explains the Positron in 60 Seconds
Safety Seconds

SLAC Today

Tuesday - June 5, 2007

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BaBar Collaboration Meeting Starts Today

This morning marks the start of a busy week for the BaBar collaboration with the opening session of this year's spring collaboration meeting. From Tuesday through Saturday, about 300 BaBarians will meet at SLAC for several days of intensive review, discussion, and planning.

"The collaboration will be looking at the performance of the PEP-II and the BaBar detector up to now and the future plans of the experiment," said BaBar Spokesman Hassan Jawahery. "We will also be reviewing more than a hundred physics measurements, which will be presented at the upcoming summer conferences."

For collaboration members, the week will be busy with plenary sessions covering topics of broad interest to collaborators, parallel sessions to allow detailed review and discussion of everything from hardware operations to physics working groups, and additional meetings related to the management and organization of the collaboration.

(Column - Safety Today)

Ergonomics: Safe Material Handling

In March, SLAC launched the SAFE '07 Campaign with an online presentation on slips, trips and falls. Ergonomics: Safe Material Handling, the second presentation in this series, is now also available on the Environment, Safety and Health (ES&H) website.

This short safety program has been designed to introduce the basic concepts of ergonomics, with special emphasis on back safety and body mechanics. Injuries from poor ergonomics—including overexertion, lifting and repetitive stress—account for about one third of medical cases diagnosed at SLAC and industry in general. A large percentage of these are due to material handling, including lifting, pushing and pulling.

The online presentation will introduce the risk factors associated with Musculoskeletal Disorders (MSDs), provide ideas on reducing those risks, and help viewers recognize early warning signs and symptoms of injuries related to material handling.

The brief (5 ½ min.) presentation, Ergonomics: Safe Material Handling, is now available. The Safe '07 Ergonomic: Material Handling website also allows you to print out a tip-sheet for reminders and offers online material for supervisors and managers to use in staff meetings or safety "tailgate" sessions.

In addition, if you haven't yet gone through the slips, trips, and falls presentation, it is still available on the same website. With more people walking about the site enjoying the warm weather, increased awareness is important in preventing this type of accident as well.

The ES&H Division is very interested in hearing what you have to say about this program. On the website is an automated survey for your feedback on this topic, as well as to suggest any others you would like to see. Have a Safe '07!

symmetry Explains the Positron in 60 Seconds

A positron is the antimatter partner of an electron. It has exactly the same mass as an electron but has the opposite electric charge. When kept separate from matter, positrons can exist forever. However, when a positron meets an electron, the two particles annihilate into a flash of energy.

Theorist Paul Dirac predicted positrons and other antiparticles in 1928. Combining the classical description of an electron's motion with the new theories of relativity and quantum mechanics, Dirac found a puzzling solution to his equations: an electron moving with negative energy, which is impossible in classical physics. He interpreted his result as an antiparticle moving with positive energy. Four years later, physicist Carl Anderson observed in a cloud chamber experiment the positron predicted by Dirac. For their discoveries, both Dirac and Anderson received Nobel Prizes.

Today, positrons have numerous applications in particle physics research and medical imaging techniques. Scientists can "reverse" the annihilation process and create large numbers of positrons by, for example, bombarding a piece of metal with an intense electron beam. Another source of positrons are radioactive isotopes such as carbon-11. Hospitals use accelerators to produce these short-lived isotopes and use them as medical markers in Positron Emission Tomography. The PET technique allows for the visualization of biological processes and systems such as blood flow, metabolism, and neuron receptors.

The latest issue of symmetry is now online.

Safety Seconds

Studies show that one or more things must go "wrong" or go "off normal" for any injury to occur during a common activity like walking around. As you engage in these activities daily, are you prepared to either make sure nothing goes “wrong”, or that you can safely deal with it if something does (like if you trip or stumble)?

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