Definition of cross sections 1 - Moodle

The SLBW formula 2The parameter σ 0 is defined as(29)σ 0 = 4π̷λ 2 g Jγ n,1 (e exc )γ 1= 2π2m 0√eexcv l (e exc )g Jγ l n,1γ 1where the expression for γ n,1 (e exc ) and ̷λ 2 were recovered from Eqs. (19) and (21),respectively. In this relation, γ l n,1 is constant. The statistical spin factor g J is defined as(30)g J =2J +1(2I +1)(2K +1)=2J +12(2I +1)since K = 1/2 for the neutron. The excited level of the compound nucleus has a spin Jfunction of the angular momentum quantum numberland consistent with the selection rules.ENE6101: Week 4 Cross sections – 25/37