Appendix A Units and Constants
300
Energy
1 electron volt (eV) =1.602 × 10 −^12 erg
1 kiloelectron volt (keV) =1.602 × 10 −^9 erg
1 million electron volts (MeV)=1.602 × 10 −^6 erg
1 joule (J) = 107 ergs
1 watt (W) = 107 ergs/s
=1 J/s
1 rad = 1 × 10 −^2 J/kg
=100 ergs/g
1 gray (Gy) =100 rad
=1 J/kg
1 sievert (Sv) =100 rem
=1 J/kg
1 horsepower (HP) =746 W
1 calorie (cal) =4.184 J
Charge
1 electronic charge =4.8 × 10 −^10 electrostatic unit
=1.6 × 10 −^19 C
1 coulomb (C) =6.28 × 1018 charges
1 ampere (A) =1 C/s
Mass and Energy
1 atomic mass unit (amu) =1.66 × 10 −^24 g
=1/12 the atomic weight of^12 C
=931 MeV
1 electron rest mass =0.511 MeV
1 proton rest mass =938.78 MeV
1 neutron rest mass =939.07 MeV
1 pound =453.6 g
Length
1 micrometer, or micron (mm) = 10 −^6 m
= 104 Å