Blogging from Brookhaven

Jay Brandes writes:

Dear Readers: I am spending this week conducting research at the National Synchrotron Light Source up in Brookhaven, New York. Now you might ask, “Why do you need to go to New York?”. jay-brandes-a.jpgThe answer has to do with a very special instrument I am using, called a soft x-ray microscope. Everyone is familiar with x-rays in the Doctor’s or Dentist’s office. Those x-rays are high energy and go right through your body, being absorbed a bit more by bones and teeth. The kind of x-rays that I am using are called “soft” x-rays, and they wouldn’t pass through a sheet of paper. Comparing the two is sort of like the comparing ultraviolet light (hard) and infrared light (soft). So what good are they? Well, soft x-rays interact with matter in interesting ways. The microscope I use has the ability to use these x-rays to give me information on incredibly tiny scales, about 50 nanometers or 50 billionths of a meter. For comparison a red blood cell is 100 times as big. The information I get is in the form of maps of different matter types at this resolution. So I can, with this instrument, literally look inside of a cell and see what is going on, where everything is located and, more importantly, what each structure is made of.

The facility I am using is one of only a handful in the country that can do this kind of analysis. These microscopes depend on a powerful source of x-ray light, generated by a “synchrotron”. A synchrotron is a beam of electrons whizzing around in a big metal tube. As these electrons go by my instrument, a device makes them wiggle a little bit, and this wiggle produces intense X-ray radiation. These x-rays are a million times brighter than those produced in your doctor’s office! These X-rays travel away from the synchrotron and to my microscope. So in one sense this big, multi-hundred million dollar facility is just a big light bulb for my instrument (as well as dozens of others around the synchrotron).

There is lots of interesting science done at these facilities, including a great deal of medical research. Many of the structures of proteins in diseases and in normal cells have been determined here by x-ray crystallography. I can’t do justice to all of this research, but please check out the NSLS web page for more details.

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