Calculating the Number of Collisions Required for Neutron Moderation

[clynne21]

Homework Statement

How many collisions will be necessary to slow a neutron down from 14.1 MeV to thermal energy (0.0253 eV)? A=24

Homework Equations

E'=[(A-1)/(A+1)]^2 x E

The Attempt at a Solution

The calculation is not an issue- I understand how to use the equation and what numbers go where.
I can use this calculation a hundred or so times to get to the thermal energy, but I'm hoping there is an equation I am missing that will give me the number of collisions instead of the energy after each collision. Any help on this would be greatly appreciated and a huge timesaver for me!

 

[tiny-tim]

hi clynne21!

(try using the X² icon just above the Reply box )

if E' = kE, then after n times E_n = kⁿE, or kⁿ = E_n/E …

can you take it from there? ​

 

[clynne21]

Hi tiny-tim!
Awesome- yes I absolutely can take it from there- thank you so much! Just have a seriously tired brain and couldn't wrap it around making that easy :-)