A simple traveling or standing wave deflecting RF cavity.
Parallel capable? : yes
GPU capable? : no
Backtracking capable? : no
Parameter Name  Units  Type  Default  Description 
L  M  double  0.0  length 
PHASE  DEG  double  0.0  phase 
TILT  RAD  double  0.0  rotation about longitudinal axis 
FREQUENCY  HZ  double  2856000000  frequency 
VOLTAGE  V  double  0.0  voltage 
FSE  double  0.0  Fractional Strength Error 

B2  double  0.0  Normalized sextupole strength, kick=(1+b2*(xy)/2)... 

TIME_OFFSET  S  double  0.0  time offset (adds to phase) 
N_KICKS  long  0  number of kicks (0=autoscale) 

PHASE_REFERENCE  long  0  phase reference number (to link with other timedependent elements) 

STANDING_WAVE  short  0  If nonzero, then cavity is standing wave. 

VOLTAGE_WAVEFORM  STRING  NULL  <filename>=<x>+<y> form specification of input file giving voltage waveform factor vs time 

VOLTAGE_PERIODIC  short  0  If nonzero, voltage waveform is periodic with period given by time span. 

ALIGN_WAVEFORMS  short  0  If nonzero, waveforms’ t=0 is aligned with first bunch arrival time. 

VOLTAGE_NOISE  double  0.0  Rms fractional noise level for voltage. 

PHASE_NOISE  DEG  double  0.0  Rms noise level for phase. 
GROUP_VOLTAGE_NOISE  double  0.0  Rms fractional noise level for voltage linked to group. 

GROUP_PHASE_NOISE  DEG  double  0.0  Rms noise level for phase linked to group. 
VOLTAGE_NOISE_GROUP  long  0  Group number for voltage noise. 

RFDF continued
A simple traveling or standing wave deflecting RF cavity.
Parameter Name  Units  Type  Default  Description 
PHASE_NOISE_GROUP  long  0  Group number for phase noise. 

START_PASS  long  1  If nonnegative, pass on which to start modeling cavity. 

END_PASS  long  1  If nonnegative, pass on which to end modeling cavity. 

DRIFT_MATRIX  short  0  If nonzero, calculations involving matrices assume this element is a drift space. 

DX  M  double  0.0  misalignment 
DY  M  double  0.0  misalignment 
DZ  M  double  0.0  misalignment 
MAGNETIC_DEFLECTION  short  0  If nonzero, deflection is assumed to be performed by a magnetic field, rather than electric field (default). 

GROUP  string  NULL  Optionally used to assign an element to a group, with a userdefined name. Group names will appear in the parameter output file in the column ElementGroup 

This cavity provides a transverse deflection that is constant as a function of transverse coordinates. It is probably the best model for a real cavity, because real cavities contain a mixture of TM and TElike modes that result in a uniform deflection.
For simplicity of use, the deflection is specified as a voltage, even though it originates in a magnetic field. The magnetic field is
 (128) 
The corresponding electric field is obtained from Faraday’s law (MKS units)
 (129) 
Assuming E_{x} = E_{y} = 0, we have
 (130) 
The change in momenta (in units of mc) in passing through a slice of length ΔL is
If we want to think in terms of a deflecting voltage, we can rewrite this as
Explanation of <filename>=<x>+<y> format: Several elements in elegant make use of data from external files to provide input waveforms. The external files are SDDS files, which may have many columns. In order to provide a convenient way to specify both the filename and the columns to use, we frequently employ <filename>=<x>+<y> format for the parameter value. For example, if the parameter value is waveform.sdds=t+A, then it means that columns t and A will be taken from file waveform.sdds. The first column is always the independent variable (e.g., time, position, or frequency), while the second column is the dependent quantity.
RFMODE