! Figure-8 ring using reversed elements and multipass.

no_digested

beginning[beta_a]   =  10; 
beginning[beta_b]   =   10
beginning[alpha_a]  =  0    
parameter[geometry] = closed
beginning[E_tot]    = 5.289e9

parameter[ptc_exact_model] =  false

!

ang = (twopi * 36.d0 / 360.d0)
Larc = 2.54948d0
brho = 1.2d0 * (Larc / ang)

kf =  2d0 / brho  ! Originally: 2.72 / brho
kd = -2d0 / brho  ! Originally: -1.92 / brho

d1 : drift, L= 2.28646d0
d2 : drift, L= 0.45d0

qf : quadrupole, l=0.5, k1= kf
qd : quadrupole, l=0.5, k1= kd 
b  : rbend,l_arc = larc, angle=ang 

bb: b, dg = -2*ang/larc

cell3 : LINE=  (d1, qd, d2, bb, d2, qf, d1)
cell4 : LINE=  (d1, qd, d2,  b, d2, qf, d1)


L3 : LINE = (bb, d2, qf, d1, 8*cell3, d1, qd, d2, bb)
L4 : LINE = ( b, d2, qf, d1, 8*cell4, d1, qd, d2,  b)


IR1: line[multipass] = (d1, qd, d2)
IR2: line[multipass] = (d2, qf, d1)

p1: patch, x_pitch = pi
p2: patch, x_pitch = -pi

*[num_steps] = 2

fig8 : line  = (ir1, L4, ir2, ir1, p1, --L3, p2, ir2);

use, fig8