There is an infinite non-multiplying medium with diffusion length 3 cm and diffusion coefficient 1 cm. There are 3 point sources of neutrons on the x-y plane:

Question

„h Source S1 = 108 s-1 at (x, y) = (2 cm, 0)
„h Source S2 = 2*108 s-1 at (x, y) = (0, 2 cm)
„h Source S3 = 4*109 s-1 at the origin.
At the point (x, y) = (2 cm, 4 cm), find:
(a) the total neutron flux
(b) the magnitude and direction of the total neutron current.

Thanks