Re: signal detector question

*To*: mathgroup at smc.vnet.net*Subject*: [mg39633] Re: signal detector question*From*: "Kevin J. McCann" <kjm@KevinMcCann>*Date*: Thu, 27 Feb 2003 00:27:08 -0500 (EST)*References*: <b3hs60$ikb$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Although it is sometimes possible to "see" the signal from a pileup, it is not usually detectable from the signal itself. There are a couple of things to look at. First, you should look at the width of the PMT signal to see the maximum number of distinguishable pulses you could handle per second say 1/(2*pulsewidth). If you are approaching this count rate you can bet that you are getting pileup. I don't know your application, but if you can put a selection of neutral density filters in to reduce the photon count, then you should see (count rate) * 10^ND ~= constant If pileup is occuring, then you will see a deviation from this for low ND (lots of photons). Hope this helps. Kevin J. McCann "The Leddons" <jleddon1 at attbi.com> wrote in message news:b3hs60$ikb$1 at smc.vnet.net... > > Hi, > Does anyone know of an example of pulse pile up and how it is detected > in a data set? This is when two photons or particles hit a detector at > the same time and get counted as one particle/or photon. Is there a way > to uncover this problem in a residuals analysis of the data distribution > for example? Would appreciate an example notebook. > > Thanks if you guys can help. > Debi-lyn > >