Question

Calculate the minimum amount of energy which a gamma ray photon should possess in order to produce a proton and an anti-proton pair.

Answer 1

Given: Mass of proton (m_p) = 1.67 × 10⁻²⁷ kg

c = 3 × 10⁸

Formula: E = 2mc²

E = 2 × 1.67 × 10⁻²⁷ × (3 × 10⁸)²

= 2 × 1.67 × 10⁻²⁷ × 9 × 10¹⁶

= 30.06 × 10⁻¹¹

= 3.0 × 10⁻¹⁰ J

∴ 1 MeV = 1.6 × 10⁻¹³ J

= `(3.0 xx 10^-10)/(1.6 xx 10^-13)`

= 1.875 × 10³

= 1875 MeV