Sextupoles

label: SEXTUPOLE,TYPE=string,APERTURE=real-vector,L=real,K2=real,K2S=real;

A SEXTUPOLE has three real attributes:

L

The sextupole length (default: 0 m). A thin sextupole is defined by setting the length to zero.

K2

The normal sextupole component $K_2=\frac{1}{B \rho}\frac{\partial^2 B_y}{\partial x^2}$. The default is $0 \mathrm{m}^{-3}$. The component is positive, if $B_y$ is positive on the positive $x$-axis.

K2S

The skew sextupole component $K_{2s}=\frac{1}{B \rho}\frac{\partial^2 B_x}{\partial x^2}$. The default is $0 \mathrm{m}^{-3}$. The component is negative, if $B_x$ is positive on the positive $x$-axis.

Example:

S:SEXTUPOLE,L=0.4,K2=0.00134;

The reference system for a sextupole is a Cartesian coordinate system.