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In this issue:
Extraordinary EXO
Safety Today: Construction Sites Off Limits
New Issue of symmetry
Safety Seconds

SLAC Today

Tuesday - April 3, 2007

EXO physicist Peter Rowson adjusts part of the cryostat thermal vacuum system. (Click on image for larger version.)

Extraordinary EXO

Later this year, the prototype Enriched Xenon Observatory (EXO) will be shipped to the New Mexico desert and lowered 2,100 feet below ground in an old mining elevator. For now, though, the observatory is in a cavernous hall on the Stanford campus, ensconced in a set of modular clean rooms to protect the equipment from radioactive materials, including human skin cells.

The observatory will search for something never seen before: a neutrinoless double beta decay, a radioactive decay that turns xenon136 into barium136 and two electrons without emitting any neutrinos. Finding neutrinoless decays will prove that neutrinos are their own anti-particle, and will tell scientists more about the mass of these nearly massless particles.

To get to the heart of the observatory, you first pull on bright white tennis shoes, turquoise gloves and a cleanroom suit. After suiting up, you enter a chamber where puffs of air from the walls blow away dust. In the innermost room, a cylindrical cryostat contains the cooling system to keep xenon—normally a noble gas—in a liquid state at about 185 degrees Fahrenheit below the freezing point of water. The detector, still being assembled in a nearby clean room, will fit inside the cryostat.   Read more...

(Column - Safety Today)

Reminder: Construction Sites Off Limits

(Photo - construction site)
Construction on the Linac Coherent Light Source (LCLS) continues to gain momentum and the site along PEP Ring Road is active with heavy equipment. This construction site represents an extreme danger to anyone who is not directly involved in the project and unauthorized SLAC employees must stay away from the construction zones. In fact, no one is allowed within the LCLS construction site unless escorted by a member of the Turner Construction Company staff.

Although the gates to the site occasionally remain open to allow for increased construction traffic, venturing out for a "peek" at the activity violates the construction safety regulations. 

Beginning this week, a guard will be posted at the gates to monitor traffic during working hours and to prevent unauthorized access to the site. Safety is always SLAC's top priority, and reinforcing this during LCLS construction is imperative. It is important that no one enters the construction zones unless specifically authorized by Turner so that everyone remains out of harm's way.


(Photo - ESHAC)
The Environment, Safety and Health Advisory Committee with Jonathan Dorfan, from left to right: Kevin Norris, Bruce Murdoch, "Griff" Griffing, Bob Casey, Larry Papay, Dorfan, and Rick Ford.

For three days this week, the Environment, Safety and Health Advisory Committee (ESHAC) convenes at SLAC. Created in 2004 on the recommendation of a university panel, this external committee visits SLAC periodically to examine the lab's ES&H programs. This year, the committee will make recommendations on which programs work and which could use updating or restructuring.

New Issue of symmetry

The most recent issue of symmetry hit virtual newsstands yesterday. This month's issue features a number of SLAC researchers as it describes the "concordance model," a cosmic recipe that unifies all astronomical observations to date. The issue also includes a commentary by DOE Under Secretary for Science Raymond Orbach about the future of the International Linear Collider. The magazine is now posted online, and print editions will arrive at mailboxes around SLAC next week.

Safety Seconds

When accused of being a risk-taker, Ed Viesturs replies "I'm not a risk-taker; I'm a risk-manager." In his effort to climb all 14 peaks over 8,000 meters high, he reached the top 20 times and had to turn back 10 other times. In all cases he turned back due to the dangers presented by the mountain and/or weather, and never due to his lack of preparation, strength, or desire.

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