Talk:Nuclear weapon yield/@comment-79.78.77.58-20170629124832

            Estimate of the yield of the Hiroshima bomb.

U 235 enrichment 80 %, q = 0.8 Mf = 64 Kg, Tungsten carbide tamper Mr = 322 Kg. Mt = 372 Kg.

Over the range of q = 0.8 to 1, the critical radius Rc to a first approximation is given by :-

Rc = ( pi Aw) / (2 p Av) { 1/ [3(n – 1) Gf* Gs* ]}^1/2.

Aw = atomic mass, Av = Avogadro constant, p = density, n = neutron yield, and Gf*, Gs* are the effective neutron cross-section for fission and scatter respectively.

Gf* = Gf235q + Gf238( 1– q ) and Gs* = Gs235q + Gs238 ( 1 –q ). ________ Gf_____ Gs. U235____ 1.24____ 4.56 x10^-24 cm2. U235____ 0.3_____ 4.8.

Gf* = 1.052×10^-24cm2, Gs* = 4.6 x 10^-24cm2, n = 3, p =18.95 gm/cm3.

Rc =6.63cm, Mc = 23 Kg.

M =64 Kg, R = 9.3 cm, n = 2.64, t = 1 x10-8 sec.

Et = Mt/2 { ( R – Rc )( 1 – (Rc/R)^2)( n – 1)/4t }^2 **.

Et = 5.39 x10^20 ergs and at 4.2 x10^16 ergs/ton TNT :- yield = 12.800 tons TNT.

Dr. Penney estimated from a ground survey a yield of 12+-1 Kilo ton TNT.
 * Based on a lecture given by Werner Heisenberg 1945.