PMT Noise Generation

The routine MCNOIS.FOR handles the relatively simple job of addition of the PMT noise. The amount of noise is governed by the second entry in the PMT titles bank ANOIS and is distributed uniformly between the two times TSTART and TSTOP given as arguments to MCNOIS.FOR. ANOIS is the mean PMT noise rate in Hz. MCNOIS uses the Numerical Recipes routine POIDEV to select a random integer NNOIS from a Poisson distribution with mean rate calculated from ANOIS. NNOIS hits are then generated for randomly selected tubes at random times between TSTART and TSTOP, and LIFTPM is used to insure the proper time ordering of the PM banks is maintained. The pulse height from the tube is not currently assigned a meaningful value (all hits, noise or otherwise, are currently the same amplitude), in future they should be drawn from the proper distributions.