Thursday, January 20, 2011

Sci-Tech @ MIT-Bates Accelerator

Dr. Genya Tsentalovich explains a
bit about particle physics, and the
creation of the universe.
The first visit of the Sci-Tech club this year began as we arrived at the MIT-Bates particle accelerator up the street in Middleton, MA.  After checking out way through the security gates, we signed in, got our group's radiation film badge, and met our guide.

Dr. Genya Tsentalovich turned out to be a really entertaining guide, and in addition to taking us through the MIT linear accelerator, taught us a lot about all of the technology that is used in running this machine.  It also turns out that he is from Siberia, which is home to one of the world's best Universities for particle physics.  According to Genya, a warm day at home in the winter is 0 F.  Woah - bring on winter!

In Physics the "Standard Model" explains how particles and the 
forces that connect them form the world we live in.

And here are some of the systems that we saw - join us on our next trip, or any Thursday when we meet to talk shop!  Next, our friends at Bates will set us up with some liquid nitrogen - wonder what we'll do with that?  Stay tuned!

High Voltage pressure relief system.  In case of a big-time electrical emergency, gigantic bolts of lightning will flow across these conductors and down to ground.

Genya assured us that it was terrifying.  Rare, but terrifying.

Here, Genya points out a fairly amazing part of the linear accelerator - a pulsed laser is piped onto a thin wafer of Gallium Arsenide.  Because Ga-As is a semi-conductor, this produces electrons, also since the laser light is polarized, the electrons produced are also polarized.  The super-control of electrons is one of the features that sets this accelerator apart from others around the world.

Describing how to control a beam of electrons with 
magnets.  Turns out it isn't as hard as you might think.

The linear accelerator isn't infinite, but it's pretty darn close. The machine itself is actually about two football fields long, and it could accelerate electrons to around 1 GeV.  At this energy, electrons travel at 99.999% the speed of light.

Just for comparison, the new CERN particle accelerator, called the LHC will have a top energy of 14 TeV, which is 1400 times higher.  Due to Einstein's theory of relativity, a proton traveling at this speed will have the same momentum as a housefly cruising around in your kitchen.  And that's a lot for a proton to have!

Here, Minh, Jake, Nick, Kevin, Jason and Raj check out a fairly

amazing system called the Siberian Snake.  This super-conducting
magnet system is used to keep the electron beam at Bates polarized.
The Siberian snake was just one of the many amazing pieces of 
technology the Bates physicists used to crank out world-class research.

Monday, November 1, 2010

Sci-Tech @ Brown

This is a bit of a serious way to begin, but it's the truth. I have known several students over the years that have lost a parent, and more often than not, cancer has been responsible for their early passing.  So the conference that I attended this weekend was exciting and full of hope on a couple of different levels.  There were at least a half-dozen speakers who addressed nanotechnology in some way. One researcher was mainly concerned with developing gene therapies, and was working on putting DNA where he wanted it using nanostructures and electric fields.

Mark Reed of Yale was another great speaker, and you can catch my very brief summary of his talk on my RET blog if you're so inclined. For me, however, the wife and husband team of Naomi Halas and Peter Nordlander of Rice University were impossible to top.  Both of them had excellent talks, and clearly work together to support each other in their research in the field of nanotechnology, but their work has such a clear and powerful human side that I have been thinking a lot about it ever since I saw them.

Naomi's story was a little bit surprising, to be honest.  I sort of expected that really bright young women would have a lot easier time becoming researchers than Naomi did, but her story speaks for itself, and demonstrates how she pushed on and in the process blazed a path for others.  Click on the link and you'll be taken to the NOVA program from several years ago in which Naomi explains quite a bit about her background and her research.  The scientific essence of her talk was fantastic: I'd heard about quantum dot particles and gold nanospheres, and I knew that they were both potentially really useful in detecting and fighting cancer.  I just had no idea how advanced the field was. It was 2002 when Naomi and colleague Jennifer West founded their spinoff company, Nanospectra Biosciences which they hoped to use to develop and market their invention, the gold nanosphere.

What makes this invention so fantastic is that depending on its design, the shell and core of the nanosphere work together to determine what wavelengths of light it will absorb.  In soft tissue cancers, such as breast and neck cancers, these nanospheres can be tuned to absorb light of around 800 nm wavelength.  Why this type of light wave? The answer's simple - you and I are mostly made of water, and water mostly doesn't want anything to do with 800 nm light waves, and so they pass through cells without anything happening to them... Until they hit the gold nanoparticles, that is!  This is where many other bits of knowledge come together: because cancer cells grow rapidly, they tend to throw out inefficient, leaky blood vessels to fuel themselves.  Gold nanoparticles are small enough to sneak in through these blood vessels, so about 1% of the nanoparticles injected into mice end up in the cancer site, while the other 99% wash harmlessly out of the body.  Infrared light from a laser is then used to illuminate the tumor site. The gold nanospheres, which were designed to absorb this color of light, get very warm, and cook off the tumor cells, which die when the temperature exceeds 54 C.

I couldn't find the exact images of the photos Naomi showed in her talk from the internet, but these give you the picture.  In the span of ten days, 100% of the mice that had cancer were free of the disease, and all of them live out their normal life spans, which is about two and a half years for mice.  What's just as amazing is that there were no side-effects whatsoever - there is no known interaction of any type in the human body for gold, so this method is potentially the safest of any cancer therapy available.  At this moment, Naomi's company is in human trials for individuals with brain cancer, a disease for which there are really no good options available to doctors.  I could explain why her company favors rods instead of spheres, but to get the real explanation, you'll have to come to the next Sci-Tech Club meeting in the Benjamin Physics Lab B129, after school.  Listen for announcements!