I had been a part of the University of Edinburgh Dark Matter Group (EdiDM) and University of Durham Institute of Particle Physics (IPPP) collaboration for the last one year. I had been working on data from the Large Underground Xenon Dark Matter Direct Detection Experiment (LUX). It is the world’s most sensitive Dark Matter Detection experiment.
It is based at Davis Cavern, Sanford Underground Research Facility (SURF), Lead, South Dakota, USA. Which happens to be the same place where the Nobel Prize winning Neutrino detection experiment was based roughly 50 years ago. The laboratory is 4850ft (roughly a mile) underground in a now decommissioned gold mine.
My trip was 4 weeks long and here is a pictorial outline of it:
After a weeks of safety training courses and videos, I was allowed to join the team down. In the background of the above picture you can see the cages used to enter and exit the mine it was a 10-15minutes ride from 4850ft to ground level.
We had to wear special reflective mining clothing while commuting up and down while carrying safety equipment such as the W65 carbon monoxide filter attached to my belt on the right in the upper picture.
A replica of the cage used to commute.
A map of the 4850 level.
Within the Davis Cavern where the actual experiment is based it’s a clean environment so external clothing had to be removed to enter.
Upper Davis Caven.
The big metal tank seen here, in the lower Davis Cavern, is filled with purified water which contains the xenon tank. The way the experiment works is that when a Dark Matter particle passes through the Xenon tank we see a light flash. The idea to be so deep underground is to be able to shield the experiment from all other radiation from Space so as to only allow the Dark Matter particles to pass through the Xenon tank.
This is a picture of all of us on the shift many of the people here are students from various universities worldwide lead by a DSCM who is a Post Doctorate researcher. My task was to help them with the day to day running of the experiment. We all were 24 hours on call in case something went wrong we had to go down. And things did go wrong quite often so we had to go down quite a few times out of hours. The experiment is quite sensitive, even lightening a mile above on ground could trigger it to trip. And if not reached and restarted within 3 hours it could die.
A model in the visiting centre of the tunnel network. The copper level is the one where the experiment is taking place.
The Homestake mine’s map where SURF is based.
This is a graphical depiction of the inside of the Water tank. However, this is of the LUX-Zeplin experiment which is the future planned experiment meant to replace the current LUX experiment after it is decommissioned in late 2016. LZ is planned to be even more sensitive and the one most likely to detect Dark Matter.
On the very last day we took a day off and went to the Devil’s Tower in Wyoming.