RF Cavities

An RFCAVITY has seven real attributes and one integer attribute:

label:RFCAVITY,TYPE=string,APERTURE=real-vector,L=real,VOLT=real,LAG=real,
      HARMON=integer,BETRF=real,PG=real,SHUNT=real,TFILL=real;

L

The length of the cavity (default: 0 m)

VOLT

The peak RF voltage (default: 0 MV). The effect of the cavity is $\delta E=\mathtt{VOLT}\sin(2\pi(\mathtt{LAG}-\mathtt{HARMON}\cdot f_0 t))$.

LAG

The phase lag [$2\pi$] (default: 0).

HARMON

The harmonic number $h$ (no default). Note that the RF frequency is computed from the harmonic number and the revolution frequency $f_0$. The frequency attribute FREQ must no longer be used.

BETRF

RF coupling factor (default: 0).

PG

The RF power per cavity (default: 0 mW).

SHUNT

The relative shunt impedance (default: $0 M\Omega/\mathrm{m}$).

TFILL

The filling time of the cavity $T_\mathrm{fill}$ (default: $0 \mu\mathrm{s}$).

Use of a cavity requires the particle momentum P and the particle charge CHARGE to be set on the relevant optics command before any calculations is performed.

Example:

CAVITY:RFCAVITY,L=10.0,VOLT=150.0,LAG=0.0,HARMON=31320;
STATIC,P=50.0,PARTICLE=ELECTRON;

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