First exercise in Cohen-Tannoudji Volume 1

[daudaudaudau]

Hi. I'm trying to solve the very first exercise in Cohen-Tannoudji Volume 1, but I can't really get anywhere. Can someone give me a hint? This is not homework. We used Bransden and Joachain in the course I just finished, so I thought I'd take a look at Cohen now.

 

[Redbelly98]

This looks like a diffraction problem.

 

[L'Aviateur]

This looks like a diffraction problem.

I agree:

sin(θ)=pλ/l

here p=1

I don't know what to do with λ though...there must be some link between λ and energie...
keep in mind that the mass of a neutron is more like 1.67*10^-27 kg

 

[Redbelly98]

Welcome to Physics Forums L'Aviateur

I don't know what to do with λ though...there must be some link between λ and energie...

Yes, indeed there is. But we do need to let the OP do some of the work here, in accordance with the Forum rules and guidelines