Calculate Flux & Current at Intersection of Neutron Beams

  • Thread starter Thread starter timman_24
  • Start date Start date
  • Tags Tags
    Current Flux
timman_24
Messages
52
Reaction score
0

Homework Statement


Two monoenergetic neutron beams I1=2*10^10 and I2=1*10^10 intersect at an angle of 30 degrees. Calculate both the flux and current in the region where they intersect.


Homework Equations





The Attempt at a Solution



I lined the first I1 up parallel to the x-axis and tilted I2 30 degrees below I1 to make the calculations easier.

attachment.php?attachmentid=32029&stc=1&d=1297136282.png


Flux:

I believe flux is the amount of neutrons passing between the left side to the right side across this arbitrary surface area. I took the surface area to span the y-z axis with the flux passing along the x-axis.

To calculate the flux, I simple did:

I1 + I2*cos(30) = 2.866*10^10 n/(cm^2-s)

Current:

I believe the current to be the vector representation of the net flow. For this I did the following:

J(Jx,Jy) = Jx + Jy
Jx= I1 + I2*cos(30)
Jy= I2*sin(30)

J(Jx,Jy) = 2.866*10^10 i +.5*10^10 j

I am not 100% positive if this is the correct way to do this. I get confused sometimes between current and flux.

Any help would be much appreciated!
 

Attachments

  • cart.png
    cart.png
    612 bytes · Views: 992
Physics news on Phys.org
I guess a lot of people have trouble with flux and current? :-p
 
Thread 'Need help understanding this figure on energy levels'
This figure is from "Introduction to Quantum Mechanics" by Griffiths (3rd edition). It is available to download. It is from page 142. I am hoping the usual people on this site will give me a hand understanding what is going on in the figure. After the equation (4.50) it says "It is customary to introduce the principal quantum number, ##n##, which simply orders the allowed energies, starting with 1 for the ground state. (see the figure)" I still don't understand the figure :( Here is...
Thread 'Understanding how to "tack on" the time wiggle factor'
The last problem I posted on QM made it into advanced homework help, that is why I am putting it here. I am sorry for any hassle imposed on the moderators by myself. Part (a) is quite easy. We get $$\sigma_1 = 2\lambda, \mathbf{v}_1 = \begin{pmatrix} 0 \\ 0 \\ 1 \end{pmatrix} \sigma_2 = \lambda, \mathbf{v}_2 = \begin{pmatrix} 1/\sqrt{2} \\ 1/\sqrt{2} \\ 0 \end{pmatrix} \sigma_3 = -\lambda, \mathbf{v}_3 = \begin{pmatrix} 1/\sqrt{2} \\ -1/\sqrt{2} \\ 0 \end{pmatrix} $$ There are two ways...
Back
Top