3.3.7 quadrupole

quadrupole defines a quadrupole. Attributes:

• l - length [m] (default 0)
• k1 - normal quadrupole coefficient k1 = 1/(B \rho) dB_y / dx [m^-2] Positive k1 means horizontal focusing of positively charged particles (default 0). dB_y / dx is the magnetic field gradient, while (B \rho) is the magnetic “rigidity”: B\rho (T*m) = p(GeV)/(0.299792458 * |charge(e)|)
• ks1 - skew quadrupole coefficient ks1 = 1/(B \rho) dB_y / dx [m^-2] where (x,y) is now a coordinate system rotated by 45 degrees around s with respect to the normal one.(default 0).
• tilt - roll angle [rad] about the longitudinal axis, clockwise.
• aper - aperture [m] (default same as beampipe radius)
• outR - external radius [m] of magnet (default set to aper+22cm)
• material - the magnet material (default set to “Iron”)

Example :

     
     qf : quadrupole, l=0.5*m , k1 = 0.5 , tilt = 0.01;