Bell’s Synchrotron Team
2010-04-12
By Nicole Sidebottom
It all started last summer when Ms. Hall went to visit the Canadian Light Source—a particle accelerator called a “synchroton”—in Saskatoon last summer, and found out about the Students on the Beamlines program. This program is an amazing opportunity for high school students to do original scientific research, and use the Canadian Light Source to analyze their results. Back at school in September, Ms. Hall shared this opportunity with her science classes, and soon a group was formed: the Bell Synchrotron Team, or BSYNC, for short, consisting of Eric Langlois, Sherry Chu, Dajian Lu, Tim Xu, and Nicole Sidebottom, as well as Bell grad Victor Malkov who helped us a lot along the way.
Of course, before we could come up with an idea for a project, we needed to figure out what exactly a synchrotron was, and what we could do with it. We found out that a synchrotron is a particle accelerator that, instead of smashing particles together, simply accelerates electrons around in a circular ring at speeds close to the speed of light. Why make electrons go round in circles, you might ask? Well, when an electron changes direction, it will emit light, in the form of photons. The electrons in the synchrotron’s storage ring emit light tangent to their circular path as they whiz around the ring, and this light travels through the straight beamlines that jut out of the storage ring. The beamlines have many “insertion devices”, “monochrometers”, and other devices that are used to make the light even brighter and pick out the specific frequency to be used in an experiment. This light is very useful to scientists, because it’s very intense (a million times brighter than sunlight), and also because, while the electrons emit all frequencies of light, a very specific frequency of light can be selected to be used. This light can be used to figure out the chemical structure of proteins and crystals, take medical images of live animals (and soon people too) and can be used to detect the amounts and different chemical forms of an element inside of something, for example, a plant.
After much brainstorming, the BSYNC team decided to grow bean plants in soil contaminated with different concentrations of titanium dioxide nanoparticles. Nanoparticles are particles that are less than 100 nanometers in size (about one quarter the size of the wavelength of visible light), and are, in a sense, halfway in between ordinary bulk matter, and individual atoms. Because they are so small, they have different physical properties than ordinary matter. For instance, pure gold nanoparticles are a deep red colour, and copper nanoparticles are classified as a super hard material, unlike ordinary copper wire which is easily bent. Nanoparticles have just recently become widely used in commercial products; titanium dioxide nanoparticles can be found in refrigerators, air fresheners, and most of all, sunscreen. Yet, scientists still know little about their properties, and what effect they might have on the ecosystems they wash up in. We submitted our research proposal to the Canadian Light Source, and were chosen to be one of only a few high school groups to be given 8 hours of beamtime to conduct our research. Beamtime, which usually costs scientists 500 dollars an hour, is the time that we were allotted to use one of the beamlines, called the “spherical grating monochrometer” beamline, which uses soft x-rays. So, we bought our nanoparticles from Sigma Aldrich, and beginning in November spent a lot of time in the chemistry room in lab coats and dust masks, carefully measuring and mixing nanoparticles and soil. We then grew our beans in the greenhouse, watering and measuring over 150 bean plants, even coming in over the winter break to tend to the beans. During this time, we were in contact with the scientists at the synchrotron, Dr. Blythe and Mr. Hodges, through video conferencing, and also Ms. Tracy Walker, who coordinates the Students on the Beamlines program. Ms. Walker came to visit Ottawa in January to help us with the project, and gave presentations about the Canadian Light Source to science classes here at Bell.
In late January, we harvested our crop of beans, selecting leaf, stem, and root samples from different concentrations. Then we dried them in an incubator and crushed them into a fine powder using a mortar and pestle (and dry ice for the difficult ones) so that they could be analyzed at the synchrotron. We ended up with 140 little glass vials of green and brown powder, and were a little concerned about what the airport security would think when we brought them on the plane! Early in February, we flew to Saskatoon. The first day we toured the synchrotron, prepared our samples to go into the synchrotron, and figured out which samples we would test in our 8 hours of beamtime the next day. The next morning, we tested our leaf sample grown in the highest concentration of titanium and found… no detectable levels of titanium! Though Ms. Walker and Dr. Blythe had told us many times that we should be prepared to scrap our plans at any minute because we would likely get results that we did not expect and were not prepared for, it was still a surprise not to find any titanium in our samples. After this first scan, we tested a few of our other samples to confirm the results. Then we tested for some other elements commonly found in plants, and found that the plants grown in contaminated soil had slightly lower levels of calcium and sodium than the control plants. However, since we only had 8 hours of beamtime, and we did not grow many plants at each concentration of nanoparticles, our experiment is far from conclusive. We can only hope that another scientist might find our results interesting and decide to pursue our findings with more experiments. The next and last day, we gave a presentation of our experiments and our finding to the scientists at the synchrotron, before flying home.
This opportunity was a truly exceptional one, and we all learned a lot about the research process, the importance of keeping good notes and labels, and of course about the synchrotron, the plants, and the nanoparticles themselves. The BSYNC team would like to thank Ms. Hall and Victor for their help throughout the project, without which this would never have happened. We also appreciated the help of Dr. Blythe and Ms. Tracy Walker, who gave us the information we needed while still making sure that we were the ones conducting the research.
You may have seen us on CBC, or if you haven’t, you can see the clip at http://tinyurl.com/bellsync.