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3.3.2 Units

The usual accelerator coordinate system is assumed (see ref)

In GMAD the SI units are used.

Length [m] (metres)
angle [rad] (radians)
quadrupole coefficient [m**(-2)]
multipole coefficient 2n poles [m**(-n)]
electric voltage [MV] (Megavolts)
electric field strength [MV/m]
particle energy [GeV]
particle mass [GeV/c**2]
particle momentum [GeV/c]
beam current [A] (Amperes)
particle charge [e] (elementary charges)
emittances [pi m mrad]

There are some predefined numerical values

pi 3.14159265358979
me electron rest mass
mp proton rest mass
GeV 1
eV 1^-9
KeV 10^-6
MeV 10^-3
TeV 10^3
m 1
mm 1^-3
cm 1^-2
rad 1
mrad 1^-3
clight 2.99792458e+8

for example, instead of one can write either 100 or 0.1 * KeV when energy constants are concerned.