beginning[beta_a] = 10.   ! m  a-mode beta function
    beginning[beta_b] = 10.   ! m  b-mode beta function
    beginning[p0c] = 1e8   ! eV  

    parameter[geometry] = open      ! or closed
    parameter[particle] = He+ 

    q1: quad, l = 0.1, k1 = 0.14
    q2: quad, l = 0.1, b1_gradient = parameter[p0c] * q1[k1] / c_light
    lc: lcavity, l = 1, voltage = 10e8, rf_frequency = 1e9
    rf: rfcavity, l = 1, voltage = 10e8, phi0 = 0.25

    lat: line = (q1, q2, lc, q1, q2, rf)
    use, lat