Geometry (44 Mev LINAC exit port)

Critical angle calculation

[math]\Theta = \frac{m_ec^2}{E_{beam}} = \frac{0.511\ MeV}{44\ MeV} = 0.67\ ^o[/math]

Beam displacement

[math]\Delta = 285.75cm\ *\ \tan(0.67^o) = 3.34cm[/math]

Experimental 90 degree exit port geometry

Off-axis collimation geometry

Off-axis calculation of critical angle

1) [math]\Delta = 3.34 cm \ \ \Rightarrow\ \ \tan^{-1}\left(\frac{3.34}{285.75}\right) = 0.67\ ^o[/math]

2) [math]\Delta = 4.72 cm \ \ \Rightarrow\ \ \tan^{-1}\left(\frac{4.72}{285.75}\right) = 0.95\ ^o[/math]