Black Hills Abstract 2013 - Cosmic Ray Muon Detector and Flow Meter

Madison Jilek, Drew Powers, Christopher Randolph, Rachel Williams

Cosmic Ray Muon Detector

The purpose of having underground labs is to get away from cosmic rays, which can create unwanted or harmful backgrounds in the results of hypersensitive experiments such as LUX and Majorana which are currently underground at the 4850 ft. level at SURF. One could use the cosmic ray muon detector to detect these potentially harmful rays. Inside the detectors, there is a photomultiplier tube (PMT) mated with a scintillator and when a muon hits the scintillator it loses energy in the form of a photon due to the change in medium, which is counted by the PMT. After taking data, someone could run flux studies, and when different people compared those studies to the atmospheric pressure, it was noticed that there was a correlation between the two. When pressure was at a low, more muons passed through our detectors, and when the pressure was at a high, less muons passed through.

Flow Meter

The flow meter project is an ongoing project at the 4850 level in the Sanford Underground Research Facility. The flow meters were built to monitor the air flow, temperature, and humidity of the ventilation. Ventilation is very important in a confined space environment wherein fresh air, radon gas expulsion, and coolant are necessary to keep the environment habitable. The flow meters were constructed, using Campbell Scientific equipment, and installed using sonic anemometers to measure air speed and flow, a pressure sensor, and a relative temperature and humidity probe to monitor the underground conditions. Our data collected showed us several correlations to the regular operations of the facility, such as the Orohondo Fan. The Orohondo Fan pulls air out of the levels in the facility with also brings out excess radon gas, old air, and heat to the surface. When the fan was turned off, air flow sharply decreased from around a consistent 70000 ft. per min to around 25000 ft. per min at the 17 Ledge, and decreased from around 80000 ft. per min to around 45000 ft. per min at the 4 Winze Wye. This shows that the data can be important to the facility when emergencies occur, such as carbon monoxide or fires, to see the direction of the emergency activity, and how to resolve the problem.



Cosmic Ray