parameter[p0c] = 1e9

q1: quad, l = 0.5, k1 = 1, tilt = 0.01  ! Tilt to give some coupling.
q2: quad, l = 0.5, k1 = -1

d: drift, l = 0.3
b: sbend, l = 0.5, angle = pi/8

rf: rfcavity, l = 0.1, rf_frequency = 500e6, voltage = 1e5

sector: line = (d, q1, d, b, d, q2, d, rf, b)
ring: line = (16*sector)

use, ring