cavity2_reverse: lcavity, tracking_method = runge_kutta, mat6_calc_method = tracking, n_cell = 2, 
rf_frequency = 1.3e9, 
field_calc = fieldmap,
L = 	0.470	, !Grid extends to 0.484
grid_field = call::cavity2_reverse_grid.bmad

!cavity2[voltage] = 5e6 ! Maximum on-axis Ez in V/m


CALL, FILE = cavity2_reverse_wall.bmad