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- type: Setup command.
- function: Set basic ring parameters necessary to calculate
synchrotron frequency, bunch length, and so on. Once the
namelist is processed and written to the standard output file, a
list of dependent quantities used in the growth rate
calculations are written to the standard output file.
&ringParameters
STRING twissFile = NULL;
double energyGeV = 0.0
double circumference = 0.0
double energyLossPerTurnMeV = 0.0
double rfVoltageMV = 0.0
long harmonicNumber = 1
double momentumCompaction = 0.0
double relativeEnergySpread = 0.0
double bunchLengtheningFactor = 1.0
STRING bunchLengthTableFile = NULL;
STRING bunchLengthUsedFile = NULL;
double longDampingTime = 0.0
double transDampingTime = 0.0
double horizontalTune = 0
double verticalTune = 0
double betaxAtRFCavities = 0
double betayAtRFCavities = 0
STRING parameters = NULL;
&end
- twissFile -- If not blank, then parameters of the lattice are
taken from the named file, which is assumed to be an elegant twiss output
file. You must turn on the radiation-integral calculation in elegant or
clinchor will complain of missing data. The data taken from the file are
energy, circumference, energy loss per turn, momentum compaction, relative
energy spread, damping times, tunes, and beta functions at the cavities.
For the last item, clinchor looks for elements of type RFCA and
RFCW. It averages the beta functions over all elements found.
If you wish to override the values in the file, simply give a nonzero
value to the appropriate namelist variable.
- energyGeV -- Energy of the stored beam in units of GeV.
- circumference -- Circumference of the storage ring in
meters. Used to calculate revolution frequency .
- energyLossPerTurnMeV -- Energy loss per turn in units of MeV.
- rfVoltageMV -- Peak RF voltage in unit of MV of cavities in ring.
- harmonicNumber -- Ratio between external RF frequency
and the revolution frequency . Used to
determine .
- momentumCompaction -- Momentum compaction factor. Used to
determine unperturbed bunch length.
- relativeEnergySpread -- Relative energy spread. Used to
determine unperturbed bunch length.
- bunchLengtheningFactor -- Ratio of expected bunch length
and unperturbed bunch length, which might be obtained from a
separate potential well calculation. This quantity doesn't
affect the calculation coherent synchrotron frequency. The bunch
lengthening factor appears only in the bunch form factor in the
effective HOM impedance expression. This bunch lengh applies to
all bunches in the calculation irrespective of the charge they contain.
- bunchLengthTableFile -- Input file of bunch length in units of seconds
as a function of charge to be used for individual bunches in the
calculation. This bunch length is used as form factor to reduce the
wake fields for a given resonator. This should be used instead of
bunchLengtheningFactor when possible.
- bunchLengthUsedFile -- Output file of bunch lengths for each
bunch defined in the calculation. Columns are bucket number, bunch current and
bucnh length. There will be one row entry for every
bucket filled. The output files is created only when
the file bunchLengthTableFile is specified. Recommended value is ``%s.bl'' where the ``%s'' is replaced with the rootname of the command file.
- longDampingTime, transDampingTime -- Coherent damping
time constants in seconds for the motions in the longitudinal
and transverse planes. If one doesn't know the coherent damping
times, one may use the synchrotron radiation damping times,
which are longer. Damping rates are calculated from the damping
times, and are simply added to the CBM growth rates to give the
final growth rates. When doing Monte Carlo studies, I prefer to
ignore the damping rates by making them explicitly zero in the namelist
by setting longDampingTime, and transDampingTime to
zero.
- horizontalTune, verticalTune -- Tunes of the stored
beam. Values are required if command doTransverseMotion is
used.
- betaxAtRFCavities, betayAtRFCavities -- Beta functions at
the RF cavities. Values are required if command doTransverseMotion is used. The transverse growth
rates will scale with one of the two values, depending on which
direction is specified in the doTransverseMotion command.
- parameters -- Output file containing above parameters
plus some calculated ones.
Next: monopoleHOMs
Up: List of Namelist Commands
Previous: List of Namelist Commands
Randy Flood
2006-11-06