# Fermi Gas Model / Fermi energy and momentum

mmisk
Hi,

Hope somebody can help - I seem to be missing the obvious and bonking

In Wong and also in Feshbach/deShalit, they calculate the Fermi momentum,
Kf using the experimental value of Rho-0 and come up with Kf=1.3 fm-1

So far so good.

Where I stumble is in their calculation of the Fermi Energy, Ef. For
instance, Wong has Ef=(hbar*Kf)^2/2M, M=nucleon mass, giving
Ef about 37 Mev. But when I plug in the appropriate values I get an
Ef of 11.2 ish Mev with M = M neutron ~939.5 Mev/c^2.

I'm sure I'm missing the obvious 'adjustment' to the privously
calculated Kf, and suspect it is a geometrical consideration as I'm
off roughly pi.

Thanks

Mike