# Plastic Scintillator Calculation

Below is the calculations done to determine the probability of pair production depending on thickness of the scintillator.

Molecules per (NOTE: is just the density of the scintillator material and N[A] is Avogadro's number)

Molecules per

Weighted cross-section

Probability of interaction (%)

All cross sections listed here are pair production cross-sections

For carbon or

For carbon or

For hydrogen or

For hydrogen or

Molecular formula for PVT

Density of polyvinyl toluene (a common scintillator material) (NOTE: this value is from Rexon RP 200 )

or is it   H/C = 11/10   (TF)


For the sample calculation the thickness will be set to 1 cm just to get probability per cm

So entering all the numbers into the 4 initial equations gives the following answers:

Molecules per

Molecules per

Weighted cross-section

Probability of interaction (%)

Doing the same calculations using the Bicron BC 408 PVT with anthracene  for the material yields a probability of

# A different way to calculate probability of interaction

I checked out a few of the physics material supply sites and most of them list with their products the amounts of each individual atom per . Therefore there is a quicker way to calculate the probability of interaction which is listed below.

Probability of interaction per cm thickness

Using this method of calculation for Rexon RP 200 yields a probability

Using this method for Bicron BC 408 yields a probabiltiy