Physics and Engineering of Radiation Detection

750 Appendix-B B. Constants and Conversion Factors

B.2 MassesandElectricalChargesofParticles

Particle Symbol Charge (multiples ofe) Mass

alpha α,^42 He++ +2 6. 644 × 10 −^27 kg

3727.379MeV

deuteron d,^21 H+ +1 3. 343 × 10 −^27 kg

1875.612MeV

electron, beta e,β -1 9. 109 × 10 −^31 kg

0.511MeV

neutron n 0 1. 675 × 10 −^27 kg

939.565MeV

positron e+,β+ +1 9. 109 × 10 −^31 kg

0.511MeV

proton p,^11 H+ +1 1. 672 × 10 −^27 kg

938.171MeV