Recent content by ElectricEel1

Homework Statement 5.5 MeV alphas hit Be-9 and produce carbon with a gamma. the Q value is 10.65 I have to find the kinetic energy of the carbon nucleus and the gamma and I am to ignore the gamma ray momentum. Homework Equations T = p^2 / 2*m Q = T_be + T_alpha - T_c - T_gam[/B]The Attempt...

This is to clarify the meV thing. "However let me clarify what occupancy in meV means. If you have a band or subband filled up to a Fermi energy, then the occupancy in meV means the energy from the bottom of the band up to the Fermi energy. In other words this is the range of states in meV...

I don't know either to be honest. So I'll use the fermi function and the 2D density of states. I know to use 50mev for the Fermi energy but what will E be? 30mev for both so theyhave equal occupancy?

is it the product of the fermi function to find probability and the density of states?

I figure I need E= (hbar^2 * pi^2 * n^2) / (2*m_eff * d^2) but then I haven't been given effective mass or well width so not sure where to go

Im taking a guess since I couldn't find any definition in the course materials but is it the number of occupied states within the band? I am not sure which other equations I need.

Homework Statement A quantum well is doped with electrons such that if it had one only one confined sub-band the Fermi energy would be 50meV. In reality the quantum well has two sub-bands with energy separation between the bottoms of the sub-bands of 30meV. Deduce what are the resultant...

i had 0.034c as the velocity of the lambda in the sigma rest frame. then using 2gev as the energy of the sigma in the lab frame, I calculated the momentum and used the relativistic momentum equation to find the sigma velocity. Then I used u' = (u-v)/(1-uv/c^2) to where u = 0.034c and v = 0.69c...

Awesome. So I already calculated the energy and now I have the configuration too? Thanks

The lambda forwards and photon backward sorry

It the lambda keeps moving forward relative to the sigma and the lambda moves backwards? The speeds of the photon and sigma are c and 0.69c

i understood the idea of the rocket part but I've been trying to use a transform to get from the speed in the sigma rest frame and got 0.7c for the speed of the lambda in the lab frame then got the energy from the momentum. i think that's the point I am missing. which velocities am i adding...

realised i did the above part wrong. I found the velocity of the sigma in the lab frame using the 2Gev energy given in the question then used that to transform from rest frame to that frame and got lambda velocity as 0.7c then found momentum as 1.085gev/c and energy 1.56Gev but maybe vanadium is...

they asked for the configuration which gives the lambda maximum energy and to calculate the energy. no, i got the velocity using the relativistic momentum equation then tried to use u' = (u-v)/(1-(uv/c^2)) to switch to the other frame but since its the rest frame i used u=0 so it just canceled...

so to switch to the moving frame i found the lambda velocity to be 0.034c and doing the velocity equation i calculated that that means the lab frame is moving at 0.034c. I am not sure if this was the right step to make