# Use the result of Problem 15 and the method of Problem 18 to find the cosine of the scattering angle

Use the result of Problem 15 and the method of Problem 18 to

find the cosine of the scattering angle in the LAB system, cos( ) _ LAB

. Does the result show that scattering in the LAB system is backward,

isotropic, or forward scattering?

Problem 18

Find the probability of isotropic scattering into a

differential solid angle is d_/4_r2 where the

differential solid angle d_ is given as 2_rsin(_COM)(rd_COM).

[Hint: Integrate over _ to get scattering in the segment]