Flat Stanley Visits the CDMS Soudan Underground Lab
I arrived at Cal from Mrs. Costello’s 5th grade class at Havens Elementary School. My Science@Cal adventure took me far from the UC Berkeley campus, all the way to the CDMS underground laboratory at Soudan, Minnesota. The Cryogenic Dark Matter Search (CDMS) underground lab searches for unseen ‘dark matter’ particles in our universe. These particles are called ‘dark matter’ because they do not reflect light. I visited the Soudan mine with Dr. Nader Mirabolfathi, an associate researcher at Cal and Jeff Yen, a junior scientist at Cal, to see one of the most exciting experiments in action. Our journey began with a plane ride to Minneapolis, Minnesota, since there is no direct flight to Soudan. This is the plane we took to Minneapolis. After the plane ride, we had to drive 200 miles north to our destination… So we started driving… And driving… And driving. We finally arrived at the Soudan mine. Nader gave me a hard hat to put on before entering the mine. The temperature was about 32ºF outside. I was freezing! The elevator in a mine is called a shaft. After a 2-minute ride in the shaft, we reached deep underground, which is 2,341 feet beneath the earth’s surface. The experiment is operated at this deep underground level in order to shield it from particles other than dark matter particles. The CDMS experiment uses very sensitive detectors to look for these mysterious, invisible particles. Here are some of the tools I used to install our detectors. With these tools, I was able to… Build this amazing instrument…Yeah!!! This is the final configuration of the “4 towers” detector. Each hexagon is called a tower. They are actually very long (deep), but in this photo, you can only see them from the top. This is the Fridge we are going to use to cool down the towers to ~0.1K. This temperature is about -273 degrees Celsius—much colder than the ground temperature outside. This very cold temperature reduces the background noise and allows the clear signals to come through. ‘Noise’ is one of the biggest problems experimental physicists encounter every day. We also need a very cold temperature because our advanced equipment only works under this condition. Wow!!! So many pipes! It seems pretty hard to understand what each pipe does. This is where the scientists can control almost everything about the experiment. Look at all these cables. Each cable has a specific purpose. After a hard day’s work, we finally rode the shaft up to the surface. I learned so much about the CDMS experiment today. And it was fun!!