Octupoles

label:OCTUPOLE,TYPE=string,APERTURE=real-vector,L=real,K3=real,K3S=real;

An OCTUPOLE has three real attributes:

L

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

K3

The normal sextupole component $K_3=\frac{1}{B \rho}\frac{\partial^3 B_y}{\partial x^3}$. The default is $0 \mathrm{m}^{-4}$. The component is positive, if $B_y$ is positive on the positive $x$-axis.

K3S

The skew sextupole component $K_{3s}=\frac{1}{B \rho}\frac{\partial^3 B_x}{\partial x^3}$. The default is $0 \mathrm{m}^{-4}$. The component is negative, if $B_x$ is positive on the positive $x$-axis.

Example:

O3:OCTUPOLE,L=0.3,K3=0.543;

The reference system for an octupole is a Cartesian coordinate system.