# fitting the collimator size into the hole through the concrete wall

I can express the distance as function of collimator size and electron beam energy E:




To fit the collimator size into the hole through the concrete wall with radius R = 8.73 cm we need to solve equation:




1) some solutions of this equation for different collimator sizes m are:





2) in general for arbitrary collimator size m the solutions are:

All energies above this line is good to run experiment for condition above

# critical collimator line condition

Also I can express the distance as function of collimator size and electron beam energy E:





If I would like that nothing hitting the 4" box to go through the collimator I need to solve equation:




1) some solutions of this equation for different collimator sizes m are:





2) in general for arbitrary collimator size m the solutions are:

All energies above this line is good to run experiment for condition above

# both solutions are together

All energies above this lines is good to run experiment for both conditions above