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In this issue:
Clearing Clouds
Safety Today: JHAMs: It's All About The Details
Dish Area Reopens Following Fires
Safety Seconds

SLAC Today

Tuesday - July 31, 2007

The circular device inside this accelerator structure coats the structure with titanium nitride to keep electron clouds in check. (Click on image for larger version.)

Clearing Clouds

Clouds might be welcome during a drought, but you definitely don't want them in your beam pipes. Researchers around the world are working out how to keep a section of the proposed International Linear Collider—the positron damping ring—clear of electron clouds.

In curved sections of accelerators, such as a damping ring, the beam throws off synchrotron radiation that plows into the beam pipe walls, kicking up electrons embedded in the wall. The newly freed electrons get pulled along with the next bunch of positrons in the beam, but then some hit the wall, freeing so-called secondary electrons. Soon a cloud of electrons clogs up the beam pipe.

"When the beam passes through a cloud, it's like a plane passing through turbulence," said Mauro Pivi, of SLAC's ILC Accelerator Design group.  Read more...

(Column - Safety Today)

JHAMs:
It's All About the Details

Performing a thorough annual Job Hazard Analysis and Mitigation (JHAM) process is an important step toward increasing safety at SLAC. Thinking about the potential risks associated with job activities helps remind employees of dangers they may encounter. And though the JHAM form is only four columns wide, there is one key element that separates an exceptional JHAM from an average one—the details.

"There are only four steps to the process," said Environmental Safety and Health Chemical and General Safety Coordinator Jim Healy. "They are listing tasks, recognizing their dangers, identifying how to control the hazards, and obtaining training that may help avoid accidents or injuries. The key is for the employee and supervisor to really take some time to think about these four things. After all, nobody knows the hazards of a job better than the employee and the supervisor."

The most common JHAM oversight seen by Karen Holtemann, who helped design the JHAM process and online examples, is a lack of detail.

"Many JHAMs don't define the tasks and associated hazards well enough," said Holtemann. "And if you don't have specifics on the hazards, you can't be specific with the controls to mitigate them."

For example, for an employee who works with chemicals, a non-specific JHAM might say something like: Task: work with chemicals. Hazard: exposure to chemicals. Controls: wear appropriate personal protective equipment. This doesn’t provide the worker with enough detail to properly protect him or herself. Quality JHAMs will dig much deeper. What parts of the body could be exposed, and how? Could there be inhalation of solvents, chemical splashes in the eyes, or acid burns to skin? What specific controls or personal protective equipment can then be used to control each of the identified potential hazards?

"It helps to sit down and ask, 'What part of the body could get hurt and how?'" says Holtemann. "From those questions, the controls will automatically fall out."

Additionally, it helps for employees with similar jobs to collaborate on their JHAMs. For more information and assistance with the development and implementation of JHAMs, please contact your Division Safety Coordinator. If you have program questions, please contact Jim Healy or Stephen Hauptman.

Dish Area Reopens Following Fires


The Stanford Dish Area

Stanford University has reopened the Dish walking paths, following a four-week closure necessitated by two brushfires that burned nearly 200 acres.

The Dish paths may again close for short periods of time when the fire danger is high. Details on the status of the paths are available on the "Foothills Hotline" at (650) 926-0275 and at the Dish gates.

University officials have been concerned about the safety of local residents and the thousands of people who use Dish paths because the fire danger has remained extremely high over the last several weeks. While fire and law enforcement officials have been investigating the cause of the two blazes, the university used the time during the closure to make improvements to reduce the risk of a catastrophic fire.

Director of Community Relations Jean McCown said university crews have expanded and enhanced firebreaks in the foothills area. In addition, the university has initiated plans to install fire hydrants behind homes on Junipero Serra Boulevard.

According to Stanford Public Safety officials, two juveniles sparked the June 25 grass fire that burned about 171 acres. The cause of the 20-acre fire in the foothills on July 5 is still under investigation. No homes or structures were damaged in either fire, and no residents were evacuated, but two firefighters at the second blaze were treated for heat exhaustion.

Safety Seconds

The average person sees a beautiful warm, blue, friendly ocean in Hawaii. But living in it makes you realize that the ocean is predictably unpredictable—large waves tend to show up in small groups every 10 to 20 minutes—so you always look for the highest wet line on the beach/rocks and stay above it. And you never turn your back to the ocean. Every year we hear of a few fishermen along the California coast who perish by ignoring the same rules.

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