Fermi Distribution Radial Dependence of Charge Density

# Fermi (or wood-saxon) distribution- Radial dependence of charge density (Suitable for medium and heavy ryclei) So P(r) = ris dist. from It e (r-c)/a the centre 1. Charge density in nuclei is Constant within nuclear interior & falls rapidly to zero at nuclear Surface. 2. C is half way radius, where density falls to half its value than that at the centre. At the centre (r=0), Po e -c/a is very Plr) = + e la small I -classi

P(r) Po t Po/2 t 0 C r r2 r, r=0 P(r) = Po For-C r= C Po Po = p(r) = lte° 2 3 a is a Constant and its called. diffusion diffuseness. It is same Constant for all nuclei 'a' has a relation with thick ness t. Thick ness-t of a nuclear surface is defined as the distance b/w the points at 10% and 90% of the maximum density fo at the centre. t= 4.49 a= 0.55fm t = 2.42fm same forall nucki

10% of s. r=r, Po Plr) = 0.1P. = It e (ri-c)/a 90% of Po r=r2 Po 2 p(r) = 0.990 = lte (ri-c)/a t= r- r2= 4.49 O r/fm) 10