the canadian light source

Sup peeps! As previously mentioned, here are a few photos from the Canadian Light Source. The CLS is a third generation 2.9 GeV synchrotron located in Saskatoon, Saskachewan. And it's friggin' awesome:



That's a view of the ring from the north end. The outer donut ring shaped structure is the hutch that covers the storage ring (where electrons go screaming around in a circle, spewing out photons all willy nilly). The inner shaped donut is the injection ring, which spits electrons into the storage ring twice a day to maintain a current of ca. 250 mAmps.

I can't claim to understand much of how synchrotron radiation is produced or the reasons behind its awesomeness, but Wikipedia sure can. For my purposes, synchrotrons are frigging awesome at producing metric buttloads of photons over a huge energy range, making them ideal for any kinds of spectroscopy. Furthermore, they usually are coupled with state-of-the-art optics systems to harness that light, such as monochromators and detectors. This makes science a very happy person.



Positioned tangentially around the outside of the ring, are beamlines optimized to look at certain ranges of photon energies (measured in electron volts) for a range of applications. The CLS has six operational beamlines ranging in energies from the far IR to extremely high energy X-rays (up to 40,000 eV!), with another five almost ready and two more in the wings. This photo above is of the Spherical Grating Monochromator (SGM) and Planar Grating Monochromator (PGM) beamlines, which together cover the soft X-ray energy range (from about 5 to 2000 eV). X-rays are of sufficient energy to cause changes in the electronic state of a material; basically, the photon headbutts a core level electron (like, say, one occupying a 1s orbital), causing it to jump into a valence electron. These transitions require just the right amount of photon energy, depending on the atom and orbitals involved. In the energy range covered by the SGM and PGM beamlines at the CLS, there are a lot of elements that will absorb the X-rays, so much so that the beamline has to be kept under high vacuum so that X-rays will reach your sample.



The above picture is of the analysis chamber on the PGM. The sample is held in the middle of the vacuum chamber, where incoming photons will hit it, causing X-ray fluorescence or other relaxation events to occur such as Auger electron emission. There are several detectors inside the chamber to record these relaxation events; the X-ray fluorescence detector is attached to the grey cylinder upon which the lamp sits in the photo above.

Running these types of experiments at a synchrotron is pretty dang complicated. As I mentioned above, the beamline has to be kept under high vacuum the whole time; Loading and pumping down your samples can be a rather time consuming process. As well, since time at any synchrotron is in extremely high demand, they run the beamlines 24 hours a day, 7 days a week. People run their experiments as fast as they can during their beamtime. It's the norm to work in shifts around the clock so that you are continually running samples. This can make for a rather wearying work schedule; I usually sleep about 8 hours over 2 and a half days and that's with two other grad students trading shifts.



However, the synchrotron sometimes don't always want to stick to that schedule. Being driven by a collosal number of power supplies, vacuum pumps, water coolers, etc etc that are prone to malfunctioning, there are a lot of factors that can contribute to a loss of beamtime. Usually it gets fixed almost immediately by the engineering staff, but sometimes it can be hours if not days if there's a major glitch. Last year a smoke alarm got tripped accidently, immediately cutting power to the whole ring and putting all research out of commission for three days! That's pretty much a lifetime at a synchrotron.

Anyway, they graph the beam stability on televisions scattered around the building, plotting beam current versus time. That sharp drop on the graph = "injection problems". That immediate spike back up = engineers doing their thang. The CLS as of late has been really really stable *knock on wood*. Hopefully as it continues to mature it will be able to maintain such a high level of excellence!



Since the CLS is located in Saskatchewan, a province with extremely strong roots in agriculture, and because the University of Saskatoon has a world class Vet School, it is involved in some pretty funky research areas, including a beamline set up to analyze live animals! It uses an imaging technique known as diffraction-enhanced imaging, and actually just recently acquired its first images of an animal.

Anyway, I'm back from an exhausting but rewarding trip. Sorry for clogging up all your internet tubes with a giant synchrotron post!

Lecture "Gig posters"

As a lover of both science and music concerts, I am desperately in love with this series of posters put out by UNC's Biology Department for visiting scientists.

They're printed by Chapel Hill screenprinters The Merch. I would totally put that on my wall!

(via BoingBoing)

Daniel Nocera's big secret paper

That mystery paper that Daniel Nocera presented on at the CSC? It finally came out in Science today (doi: 10.1126/science.1162018) as a ScienceXpress [1].

It's all electrochemistry mumbo-jumbo, which uses some sort of implied Co2+ catalyst to split water. I can neither claim to understand or describe it, so here's an idea: the first person to respond in the comments with a plain English explanation of the concepts gets a prize. A prize of solid gold![2]

(Via Digg, if you can believe it or not. Science news travels quickly!)

1. Lamest name ever, seriously. The AAAS should rename it ScienceXXpress (science-double-x-press)!

2. Okay, maybe just gold nanoparticles. Okay, maybe just a mixtape and a piece of science memorabilia. Of solid gold! Actually, you can negotiate the prize after you explain the science. Prize money tops $25.

live from the CSC!

Hi there internet,

I've been running around this week like a headless chicken[1] trying to absorb as much of the science as possible at this year's CSC, albeit unfortunately missing some probably amazing talks. My body can only take so much, you know. I'm actually supposed to run off to a mixer right now, with the enticement of free drinks and food. Hmmm. maybe that's part of why I have been able to go to as many talks as I wanted?

Apart from the colossal disappointment that has been the conference food[2], I have seen a really great time, and actually enjoyed some amazing talks. So, brief recap:

-Daniel Nocera from MIT gave a BADASS talk on global energy needs and solar conversion. That man has guts, probably because he has the science to back it up. The climax of his talk was results that he didn't even present- he just told everyone to watch Science. Nonetheless, he still had some wicked stats on energy; well worth the read:

• “Powering the Planet: Chemical Challenges in Solar Energy Utilization”; Nathan S. Lewis and Daniel G. Nocera, Proc. Natl. Acad. Sci. 2006, 103, 15729-15735.
  
  
• “The Global Energy Future: The Challenge for Science in the 21st Century”; Daniel G. Nocera, Daedalus 2006, 135, 112-5.

-Right after that, Greg Scholes gave a pretty sweet talk, though I was distracted by his amazingly hip wardrobe and accent. I swear, I thought I saw him playing bass last year when Interpol played. I've never seen a cardigan/tight pants combo so fashionable with so much quantum to back it up.

• Gregory D. Scholes, "Controlling the Optical Properties of Nanoscale Systems” Adv. Funct. Mater. 18, 115–1172 (2008).
  
• Gregory D. Scholes, “Insights into Excitons Confined to Nanoscale Systems: Electron–hole Interaction, Binding Energy and Photodissociation” ACS Nano 2, 523–537 (2008).
• Gregory D. Scholes & Garry Rumbles, “Excitons in Nanoscale Systems” Nature Materials 5, 683–696 (2006).

- Being from the U of A, I helped with the organization of a symposium, though it was a little out of my subject area. While I respect and admire Chemical Education research, especially as a new TA, I have to admit my expectations were kind of lowish as I missed some other presentations that looked nifty. However, and I should disclose that one of my favourite talks was from my first-year chemistry prof, I was blown away by the session. Teaching is equal parts public speaking, thoughtful communication, personality and some really innovative visualization techniques. It was genuinely exciting to be there as a chemistry major who knows just how much non-chemists dislike the discipline, and the people who are working to fix that. I feel a little guilty for being such a nob in first year. If you happen to be a teaching prof, please please please go check out this links that will definitely merit some further blogging:

• The King's Center for Visualization in Science: free visualization applets and course material for teachers (disclosure: these are my peeps)!
  
• Scivee.tv: very web 2.0 way to publish, if you're into that sort of thing. who knows, maybe it'll be the next Nature!
  

Anyway, I'll try to post some more with cool things I encountered. Infiniflux, forever!

From your chemistry pal,
Joel


[1]. I kid you not, I typed that phrase into the google with no knowledge of the random weirdness that resulted.


[2]. Not including the free food at this mixer, but the general lack of food at coffee breaks and poster sessions has made me grumpy. I won't name any names (I guess apart from linking to the conference page, whoops), but if you are ever going to a major conference here in Edmonton, make sure to pack a lunch.