7 Design and Principles of Linear Accelerators and Colliders
315
Table 7.5
Symbols and constants used in the text
Symbol
Description
Notes
Symbol
Description
Notes
e
Absolute electron charge
1.6
× 10 −19
C
L
0
Length of the linac
(m)
c
Speed of light
299,792,458 m/s
k
β
Average lattice focusing strength
(1/m)
N
Bunch population
Number of particles
Z
Impedance
(
q
Bunch charge
q
= Ne
W
, 0
Wake: longitudinal monopole
(V/C/m)
σ
z
r.m.s. bunch length
(m)
W
⊥, 1
Wake: transverse dipole
(V/C/m/mm)
E
Bunch energy
(GeV)
W
⊥, 2
Wake: transverse quadrupole
(V/C/m/mm 2
)
l
b
Bunch-to-bunch distance
(m)
V
Cavity voltage
V
= GL
L
Length of a cavity
(m)
G
Cavity accelerating gradient
(V/m)