Jul 01

Too Much Noise!

At one time or another, we have all “heard” our name called in public places when in reality no one was actually calling us.  It can be a problem when we mistake something we actually hear or see with something else.  When dealing with cosmic ray detectors, background noise can be an issue as well.

At NDQC, one of the projects of the cosmic ray group is to count muon coincidences.  They do this by placing a few detector paddles on top of one another and attaching them to a photo multiplier tube (PMT).  The muons are the only particle heavy enough to travel through all of the detectors on top of one another.  Because of this, the noise can be eliminated as a muon because it won’t be detected by all of the paddles at the same time.  The detectors will only make a count when the muon is detected by all of the paddles at the same time.

One problem that may also come up is the possibility of accidentals.  Two different muons may be counted as a muon coincidence if they happen close together in time.  Those have to be eliminated from the count as well as the noise.