In March, I traveled to Lead, South Dakota to visit the Large Underground Xenon (LUX) dark matter detector, located in the defunct Homestake Gold Mine. That location has a storied history: it was the site of the Homestake experiments that provided the first hints of neutrino oscillation. It’s a good place for a lab, since it’s a seismically quiet region, and the deep tunnels of a mine provide shielding from cosmic rays.
LUX is both a simple and incredibly sophisticated experiment, consisting of a lot of cold ultra-pure xenon in both liquid and gaseous states. It’s also inside a huge tank of water, so you can’t exactly get close to the apparatus, but I was still able to tour the lab, talk to some of the researchers, and generally get a feel for how modern dark matter-hunting happens. I wrote about my experience — and the experiment itself — for Ars Technica. It’s a tale of rattling mining cages, snowfalls in March, graduate student life a mile underground, and combustion toilets.
However rustic the approach, the lab itself is a typical, sleek modern facility: all shiny pipes, metal stairways, and tile floors. The typical accoutrements of office life abound. There are computers, white boards, water coolers, and (that most necessary piece of lab equipment) espresso machines all underground. University College London PhD student Sally Shaw told me “You kind of forget you’re underground down there.” Additionally, the researchers have adorned the lab with personal touches. A warning sign admonishes visitors to not feed the scientists, and when I looked around, I spotted a few paper unicorns sitting on various shelves. Shaw said the unicorns probably started as a late-night boredom project, but they grew into an inside joke. After all, hunting for dark matter is like looking for unicorns. [Read more…]
This article is the first installment of a three-part series on dark matter. Keep an eye out for parts 2 and 3 (which will be less elaborate, but hopefully still interesting!).