Function k_squared 

pub fn k_squared(energy_ev: f64, awr: f64) -> f64

Neutron wave number squared k² in fm⁻².

k² = 2·μ·E_cm / (ℏc)² = 2·m_n·[AWR/(1+AWR)]²·E_lab / (ℏc)²

where μ = m_n · AWR / (1 + AWR) is the reduced mass, E_cm = E_lab · AWR / (1 + AWR) is the center-of-mass energy, and the two factors of AWR/(1+AWR) come from μ and E_cm respectively.

SAMMY Reference

• rml/mrml03.f Fxradi: Zke = Twomhb × √(Redmas × Factor) where Redmas = AWR/(1+AWR) and Factor = AWR/(1+AWR).

Arguments

• energy_ev — Neutron energy in eV (lab frame, as stored in ENDF).
• awr — Ratio of target mass to neutron mass (from ENDF).