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In this issue:
Light in Lock-step
Safety Today: Staying Warm and Safe With Space Heaters
DOE Establishes New Safety and Health Program
Safety Seconds
On the Web: ILC Symposium at Fermilab

SLAC Today

Tuesday - March 6, 2007

(Graphic - Coherent Light)

Light in Lock-step

Laser light, like the light that will be produced by the Linac Coherent Light Source (LCLS), has a unique property that makes it very different from more familiar sources like light bulbs or the sun. This property, called "coherence," is a unique feature of lasers and is the same property that enables a laser pointer to shine a thin beam that holds its shape over a great distance. But what does it mean to say that light is coherent?

Light can be understood as a series of waves of electromagnetic energy—just like radio waves, but oscillating at a much higher frequency. Light is said to be coherent when all the waves in a beam are oscillating at exactly the same frequency, in lock-step with one another, with their peaks and valleys overlapping perfectly. Achieving this lock-step is a bit like making light waves march together like soldiers in formation. Normal incoherent light, by contrast, is more like a disorganized parade, with everyone walking in various directions at their own leisure.

As a light source, the LCLS will differ in this regard from SLAC's other light source, SPEAR3, which produces incoherent x-ray light. The tiny wavelength of the x-rays make synchrotron light much easier to focus into a tight spot than visible light, giving SPEAR3 the power to make images of objects that are extremely small. However, coherent x-rays from the LCLS will take light-source science one step further, enabling images of even smaller objects as they vibrate and change on extremely rapid timescales. With the LCLS, researchers hope to one day make "molecular movies" of chemistry in action, giving us a direct glimpse of the frenetic motion of the molecular world.

(Column - Safety Today)

Staying Warm and Safe With Space Heaters

(Photo - space heater)Although the weather is warming, it's important to remember space heater safety when staving off winter's lingering chill. The improper use of space heaters can cause electrical problems.

Before plugging in an approved space heater, please have a Conventional and Experimental Facilities (CEF) electrician inspect the wall plug to reduce the chances of overloading an existing circuit and causing power failure. The building manager should also check to make sure the space heater will not cause problems and that the area can't be warmed by adjusting the building's HVAC system.

During use, a heater should be kept away from all objects, especially those made of combustible materials. It should be kept in plain sight, and plugged directly into a wall outlet—not an extension cord or power strip.

When it isn't warming an occupied space, the space heater should be turned off. To avoid breaking the plug, melting the cord, or causing minor shocks and shorts, a space heater should be given ten minutes to cool before it is unplugged at its head—not pulled from the socket by the cord.

Please contact the Electrical Safety Officer at x2039 with additional questions, or see chapters 8 and 12 of the ES&H Manual.

Safety Seconds

The cockpit voice recorder from the recent plane crash in Kentucky caused by pilots using the wrong runway shows the pilots not only breaking the sterile cockpit rule (described in a previous article) to talk about sick children and a pilot who failed a simulator test, but also commenting during the takeoff roll "that is weird with no lights," referring to the fact that they were taking off on an unlit runway. Unfortunately, ignoring both the sterile rule and the mountain goat proved to be a fatal combination. They also failed to use another quick safety check—read next week's column to learn more.

On the Web:
ILC Symposium

The Fermilab Community Symposium on the International Linear Collider will take place at Fermilab tomorrow at 11:00 a.m. PST (not 9:00 a.m. as previously published in SLAC Today). Speakers include Fermilab Theorist Chris Quigg, Global Design Effort Director Barry Barish, and Fermilab Director Pier Oddone. Streaming video of the symposium will be available here.

DOE Establishes
New Safety and
Health Program

The Department of Energy has recently established a new Worker Safety and Health Program (WSHP). The program makes practices already in existence at SLAC enforceable by law.

Like all DOE contractors, the lab is now required to submit a written WSHP—a master document which serves as a "roadmap" to safety and health regulations—to the Stanford Site Office. The new regulations combine DOE worker safety and health orders and a variety of national safety standards, including Occupational Safety and Health Administration and National Fire Protection Association orders. The WSHP also incorporates into one document existing Integrated Safety and Environmental Management Systems (ISEMS) and all ES&H chapters associated with worker safety and health.

The program covers non-radiological safety and health issues comprising a large portion of activities at SLAC, and includes information about the rights and responsibilities of all employees. Although most of the practices have long been implemented here, new posters will soon be displayed emphasizing workers' rights to:

- Notify the DOE site office about
   hazards,without reprisal.
- Access all safety and health
   documents that apply to the
- Have an employee-appointed
   representative accompany the
   DOE during an inspection.
- Observe monitoring and
   measuring of hazardous agents
   and receive the results of that
- Decline to perform a task it
   appears to pose a threat of
   serious physical harm.

Access the full program description here. Contact Brian Sherin, the WSHP program manager, at x5082 with additional questions.

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