# Neutron Current Question

1. Sep 19, 2012

### doublemint

Hello!

J(Ω) = ∫n(Ω)vΩ

This is a neutron current question. It wants me to figure out the net neutron flux (and direction) through a unit area of the xy plane. It gives an equation for n(Ω) = (1/4π)(1-cosθ), but I am trying to figure out what Ω is inside the intergrand because that is where the direction comes from.
I know it is the unit vector, but what is it?? Since I am integrating over a solid angle, the vector should be in spherical coordinate notation? I feel like I should know this, but I am just confusing myself in the process of figuring it out.
Any help is appreciated!

n(Ω) - expected neutron density
v - neutron speed - 2200m/s
dΩ - solid angle

DM

2. Sep 19, 2012

### doublemint

Never mind, I think I got it..