First Impressions of SURF at the 4850 Level

Sanford Laboratory Director Walter Weinig (far right) guides a group of DUNE collaborators at the 4850L; pictured in the Davis Campus near the Yates Shaft.

Wednesday, May 18 was a nice day for driving from Rapid City to Lead for an underground tour of SURF.

DUNE will be installed at the foot of the Ross Shaft, but since the shaft is being upgraded, our group of about thirty met in the surface building at the Yates Shaft. There we went over the safety instructions and gathered the required personal protection equipment (PPE) before piling into a cage like sardines to descend to the 4850 level.

The seemingly long ride was a bit noisy, with occasional drips of water coming through the top. The temperature was mild and the air was fresh. The ride actually took only about ten minutes — we are not used to slow, open-top, mining cages.

At the bottom is the well-lit Davis Campus, where Majorana Demonstrator and LUX are located. Shotcrete covers the rock surface in this area and the flooring is epoxied, likely similar to what DUNE will have. Folks in coveralls worked inside the ultra-clean experimental area of the Majorana Demonstrator. An energetic young experimenter introduced us to the LUX experiment and the future LZ project.

Our headlamps provided the only light for the kilometer-long walk through the tunnel from the Davis to the Ross Campus, giving us a taste of the daily life of the miners. The rock surface was covered with wire mesh to prevent rock fall and the floor was rough. Even with PPE boots on, we walked slowly and watched our steps.

Currently the underground Ross Campus houses an electroforming laboratory, a laboratory for biological research, a low-background counting facility, and CASPAR, all of which look adequately equipped. However, nobody was there working, so we just took a peek and moved on. We stopped by the test blast site and learned about the tests. That is as close as we could get to where the detector caverns will be excavated.

Our four-hour tour gave us a good idea of the future working conditions for DUNE – nicer than what the miners had! The key difference between working at the 4850L and on the surface is the safety requirements; otherwise, it doesn’t feel so different.

I look forward to a future trip when I can see a huge detector cavern!