SLAC Today is available online at:

In this issue:
From the Director: Tragedy at Yale
Saint Lawrence String Quartet Noontime Concert Today
Word of the Week: Coherent Optical Transition Radiation

SLAC Today

Friday - April 15, 2011

From the Director: Tragedy at Yale

(Photo - Persis Drell)
(Photo by Brad Plummer.)

Many of you may have seen the news story. Michele Dufault, a Yale senior majoring in astronomy and physics, was found dead early Wednesday after her hair got caught in a lathe in a laboratory accident.

This tragedy really hit home for me. I spent many hours as a graduate student in the student machine shop at UC Berkeley. I had waist-length hair at the time, usually pulled back in a pony tail. I had been trained to use the machines so I knew that I shouldn't wear any jewelry in the shop, I should tie my hair back, I should avoid wearing loose clothing, and use proper eye protection.

In the early days, I was terrified of the machines and was extremely careful about following all of the rules. But as I became a better and more experienced machinist, I remember being less afraid and probably got sloppier about following the rules. I'm sure I started to cut corners a bit when I was in a hurry. Then a friend got hurt working alone late one night. She lost one of her front teeth when she forgot to remove the chuck key on the lathe and it flew up into her face. Luckily, this was not a life-threatening injury, but it taught me a lesson. While work planning and control was not something I consciously thought about in those days, as a result of that accident, I found myself doing a better job of thinking through the hazards of my work before I executed it and thinking about how to do future activities even more safely. It renewed my commitment to the discipline of working safely in the shop, and above all following the simple guidelines that helped ensure my safety and the safety of those working around me.  Read more...

Saint Lawrence String Quartet Noontime Concert Today

(Photo - The St. Lawrence String Quartet)
The Saint Lawrence String Quartet. (Photo by Anthony Parmelee.)

The Saint Lawrence String Quartet will present a concert today from noon to 1 p.m. in Kavli Auditorium. The SLSQ is an outstanding group of musicians, and it is the quartet-in-residence at Stanford. They have performed in venues across the country as well as abroad. We are indeed honored for them to come to us.

They will perform "Omaramor" for solo cello by Osvaldo Golijov, and the String Quartet No. 15 in G major, D. 887 by Franz Schubert. The program is free and open to all. Please join us!

Word of the Week:
Coherent Optical Transition Radiation

(Image courtesy Joe Frisch.)

When a high-energy electron passes through a thin metal foil, its electric field is reflected away from the electron beam in the form of visible light. Known as optical transition radiation, this light is generally rather dim, since in a typical electron beam the electrons hit the foil randomly and generate light in a scattershot fashion.

However, in the very bright beams of the Linac Coherent Light Source, electrons in a bunch can be further concentrated in "microbunches" at distances that correspond to wavelenghs of light. As the microbunches hit the foil they radiate energy in visible light that is as much as 10,000 times brighter than OTR, in a process known as coherent optical transition radiation. Unlike regular OTR, which is blue-white, this light can have a variety of colors, as shown by the bright red-orange light in the image.




 Lab Announcements

Community Bulletin Board


Lab Training

Upcoming Workshops & Classes


dividing line
(Office of Science/U.S. DOE Logo)

View online at