3.3.9 octupole

octupole defines an octupole. Attributes:

• l - length [m] (default 0)
• k3 - normal octupole coefficient k3 = 1/(B \rho) d^3 B_y / dx^3 [m^-4] Positive k3 means horizontal focusing of positively charged particles. (default 0)
• ks3 - skew octupole coefficient ks3 = 1/(B \rho) d^3 B_y / dx^3 [m^-4] where (x,y) is now a coordinate system rotated by 30 degrees around s with respect to the normal one.(default 0).
• tilt - roll angle [rad] about the longitudinal axis, clockwise.
• outR - external radius [m] of magnet (default set to aper+22cm)
• material - the magnet material (default set to “Iron”)

Example :

     
     of : octupole, l=0.5*m , k3 = 0.5 , tilt = 0.01;