Contamination Control Study on Mine Dust

In order to ensure that the Sudbury Neutrino Observatory (SNO) is clean, some simple methods need to be developed for the cleanliness monitoring program. Two methods arc selected and examined. The two methods. X-ray fluorescence and optical counting, can be used for detecting and quantifying the amount of mine dust on flat surfaces. X-ray fluorescence is based on element detection, a method that yields mine-dust mass measurement, whereas optical analysis is a particle counting technique that gives the number of mine-dust particles versus size. Samples with different amounts of mine dust are collected from the mine and/or generated with a modified glove-box at the lab by using tape-lift tests, wipe tests, and witness-plates. A standard procedure is developed, and the results of applying the two methods arc summarized and presented in both tabular and graphical forms. According to the study results. X-ray fluorescence is better in mine dust mass detection than optical counting. Also, the mass/cm^ correlates better with the number of particles/cm 2 having larger diameters. Finally, four sets of calibrated samples with mine dust level from 0.6 to 13.5 A*g/cm2 are made and will be used in the observatory’s cleanliness program.