SNO detects neutrinos because neutrino interactions in water produce small flashes of light which are detected by the array of photomultiplier tubes around SNO's volume of heavy water.
This is a photo taken with a fish-eye lens from the very bottom of the SNO detector just before the last photomultiplier tubes were installed.
Each photomultiplier can detect a single photon of light and determine its arrival time with an uncertainty 1.5 nanoseconds (billionths of a second). This accuracy allows analysis to figure out where the light was produced and to reconstruct the cone-like pattern of light produced.
Shown below is one such neutrino event. The cone structure of the light is very clearly defined. The red lines show the direction of the cone from the reconstructed position of the events. Each yellow circle is a photomultiplier tube which detected light.
Of course, our goal is to understand the ensemble of neutrino data from the sun, not just individual events. This exciting work is being done now and when the collaboration is ready, we will, as a collaboration, publish our results in recognized academic journals and conferences.
|URL: sno/queens/analysis.html (Last revised Feb 5, 2002)
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