def __init__(self, baserf_gap):
"""
Constructor for the axis field RF gap.
E0L parameter is in GeV. Phases are in radians.
"""
AbstractRF_Gap.__init__(self,baserf_gap.getName())
self.setAsFirstRFGap(baserf_gap.isFirstRFGap())
self.baserf_gap = baserf_gap
self.setType("axis_field_rfgap")
self.addParam("E0TL",self.baserf_gap.getParam("E0TL"))
self.addParam("mode",self.baserf_gap.getParam("mode"))
self.addParam("gap_phase",self.baserf_gap.getParam("gap_phase"))
self.addParam("rfCavity",self.baserf_gap.getParam("rfCavity"))
self.addParam("E0L",self.baserf_gap.getParam("E0L"))
self.addParam("EzFile",self.baserf_gap.getParam("EzFile"))
self.setPosition(self.baserf_gap.getPosition())
#---- aperture parameters
if(baserf_gap.hasParam("aperture") and baserf_gap.hasParam("aprt_type")):
self.addParam("aperture",baserf_gap.getParam("aperture"))
self.addParam("aprt_type",baserf_gap.getParam("aprt_type"))
#---- axis field related parameters
self.axis_field_func = None
self.z_step = 0.01
self.z_min = 0.
self.z_max = 0.
self.z_tolerance = 0.000001 # in meters
self.phase_tolerance = 0.001 # in degrees
#---- gap_phase_vs_z_arr keeps [pos,phase] pairs after the tracking
self.gap_phase_vs_z_arr = []
#---- The position of the particle during the run.
#---- It is used for the path length accounting.
self.part_pos = 0.
#---- The RF gap model - three points model
self.cppGapModel = RfGapThreePointTTF()
def setLinacTracker(self, switch = True): """ This method will switch RF gap model to slower one where transformations coefficients are calculated for each particle in the bunch. """ AbstractRF_Gap.setLinacTracker(self,switch) if(switch): self.cppGapModel = RfGapThreePointTTF_slow() else: self.cppGapModel = RfGapThreePointTTF()
def __init__(self, axis_field_rf_gap):
"""
Constructor for the axis field RF gap.
The axis_field_rf_gap is the instance of the AbstractRF_Gap class.
E0L parameter is in GeV. Phases are in radians.
"""
AbstractRF_Gap.__init__(self, axis_field_rf_gap.getName())
self.setType("GAP&Q")
self.axis_field_rf_gap = axis_field_rf_gap
self.addParam("E0TL", self.axis_field_rf_gap.getParam("E0TL"))
self.addParam("mode", self.axis_field_rf_gap.getParam("mode"))
self.addParam("gap_phase",
self.axis_field_rf_gap.getParam("gap_phase"))
self.addParam("rfCavity", self.axis_field_rf_gap.getParam("rfCavity"))
self.addParam("E0L", self.axis_field_rf_gap.getParam("E0L"))
self.addParam("EzFile", self.axis_field_rf_gap.getParam("EzFile"))
self.setPosition(self.axis_field_rf_gap.getPosition())
#---- aperture parameters
if (axis_field_rf_gap.hasParam("aperture")
and axis_field_rf_gap.hasParam("aprt_type")):
self.addParam("aperture", axis_field_rf_gap.getParam("aperture"))
self.addParam("aprt_type", axis_field_rf_gap.getParam("aprt_type"))
#---- axis field related parameters
self.z_step = 0.01
self.z_min = 0.
self.z_max = 0.
#---- gap_phase_vs_z_arr keeps [pos,phase] pairs after the tracking
self.gap_phase_vs_z_arr = []
#---- The position of the particle during the run.
#---- It is used for the path length accounting.
self.part_pos = 0.
#---- The RF gap model - three points model
self.cppGapModel = RfGapThreePointTTF()
#---- If we going to use the longitudinal magnetic field component of quad
self.useLongField = False
#---- quadrupole field sources
#----quads_fields_arr is an array of [quad, fieldFunc, z_center_of_field]
self.quads_fields_arr = []
#---- If it is true then the this tracking will be in the reversed lattice
self.reversed_lattice = False
The script will compare TTF from the C++ class with the direct integration of the TTF integrals. """ import sys import math import random from bunch import Bunch from orbit_utils import GaussLegendreIntegrator # from linac import the RF gap classes from linac import BaseRfGap, MatrixRfGap, RfGapTTF, RfGapThreePointTTF from orbit.sns_linac import Drift rf_gap = RfGapThreePointTTF() rf_frequency = 400.0*1.0e+6 # in Hz dz = 0.01 # in m Em = 12.0e+6 # in V/m E0 = 13.2e+6 # in V/m Ep = 14.0e+6 # in V/m #kappa = 2*PI*frequency/(c*beta) c_light = 2.99792458e+8 beta = 0.5 kappa = 2*math.pi*rf_frequency/(c_light*beta) print "kappa =",kappa a_param = (Ep-Em)/(2*E0*dz) b_param = (Ep+Em-2*E0)/(2*E0*dz*dz)
class AxisFieldRF_Gap(AbstractRF_Gap):
"""
The RF gap representation that uses the RF axis field. User have to provide the
input file with this field. This function should be normalized to the integral of 1.
The absolute value of the field will be calculated as cavAmp*E0L*Field(z).
The three point tracker RfGapThreePointTTF will be used to track the Bunch instance.
The longitudinal step during the tracking z_step should be defined externally. The
default value is 1 cm. The minimal and maximal longitudinal coordinates z_min
and z_max could be used directly from the axis field file or can be corrected
externally to avoid overlapping of electric fields from neighboring gaps.
The instance of this class has the reference to the BaseRF_Gap instance and uses
it as a source of information.
"""
#---- static test bunch for the design phase calculation
static_test_bunch = Bunch()
def __init__(self, baserf_gap):
"""
Constructor for the axis field RF gap.
E0L parameter is in GeV. Phases are in radians.
"""
AbstractRF_Gap.__init__(self,baserf_gap.getName())
self.setAsFirstRFGap(baserf_gap.isFirstRFGap())
self.baserf_gap = baserf_gap
self.setType("axis_field_rfgap")
self.addParam("E0TL",self.baserf_gap.getParam("E0TL"))
self.addParam("mode",self.baserf_gap.getParam("mode"))
self.addParam("gap_phase",self.baserf_gap.getParam("gap_phase"))
self.addParam("rfCavity",self.baserf_gap.getParam("rfCavity"))
self.addParam("E0L",self.baserf_gap.getParam("E0L"))
self.addParam("EzFile",self.baserf_gap.getParam("EzFile"))
self.setPosition(self.baserf_gap.getPosition())
#---- aperture parameters
if(baserf_gap.hasParam("aperture") and baserf_gap.hasParam("aprt_type")):
self.addParam("aperture",baserf_gap.getParam("aperture"))
self.addParam("aprt_type",baserf_gap.getParam("aprt_type"))
#---- axis field related parameters
self.axis_field_func = None
self.z_step = 0.01
self.z_min = 0.
self.z_max = 0.
self.z_tolerance = 0.000001 # in meters
self.phase_tolerance = 0.001 # in degrees
#---- gap_phase_vs_z_arr keeps [pos,phase] pairs after the tracking
self.gap_phase_vs_z_arr = []
#---- The position of the particle during the run.
#---- It is used for the path length accounting.
self.part_pos = 0.
#---- The RF gap model - three points model
self.cppGapModel = RfGapThreePointTTF()
def setLinacTracker(self, switch = True):
"""
This method will switch RF gap model to slower one where transformations
coefficients are calculated for each particle in the bunch.
"""
AbstractRF_Gap.setLinacTracker(self,switch)
if(switch):
self.cppGapModel = RfGapThreePointTTF_slow()
else:
self.cppGapModel = RfGapThreePointTTF()
def readAxisFieldFile(self,dir_location = "", file_name = "", z_step = 0.01):
"""
Method. Reads the axis field from the file. User have to call this method.
There is no other source of information about the axis field.
"""
if(file_name == ""):
self.axis_field_func = RF_AxisFieldsStore.addAxisField(self.baserf_gap.getParam("EzFile"),dir_location)
else:
self.axis_field_func = RF_AxisFieldsStore.addAxisField(file_name,dir_location)
z_min = self.axis_field_func.getMinX()
z_max = self.axis_field_func.getMaxX()
self.z_step = z_step
self.setZ_Min_Max(z_min,z_max)
def getAxisFieldFunction(self):
"""
It returns the axis field function.
"""
return self.axis_field_func
def setAxisFieldFunction(self,axis_field_func):
"""
It sets the axis field function.
"""
self.axis_field_func = axis_field_func
def getZ_Step(self):
"""
Returns the longitudinal step during the tracking.
"""
return self.z_step
def setZ_Step(self,z_step):
if(self.axis_field_func == None):
msg = "Class AxisFieldRF_Gap: You have to get the axis field from a file first!"
msg = msg + os.linesep
msg = "Call readAxisFieldFile(dir_location,file_name) method first!"
orbitFinalize(msg)
length = self.getLength()
nParts = int(length*1.0000001/z_step)
if(nParts < 1): nParts = 1
self.z_step = length/nParts
#---- this will set the even distribution of the lengths between parts
self.setnParts(nParts)
def getZ_Min_Max(self):
"""
Returns the tuple (z_min,z_max) with the limits of the axis field.
These parameters define the length of the node. The center of the node
is at 0.
"""
return (self.z_min,self.z_max)
def setZ_Min_Max(self,z_min,z_max):
"""
Sets the actual longitudinal sizes of the node. It is used for small correction
of the length to avoid fields overlapping from neighbouring gaps.
"""
self.z_min = z_min
self.z_max = z_max
length = self.z_max - self.z_min
self.setLength(length)
self.setZ_Step(self.z_step)
def getEzFiled(self,z):
"""
Returns the Ez field on the axis of the RF gap in V/m.
"""
rfCavity = self.getRF_Cavity()
E0L = 1.0e+9*self.getParam("E0L")
rf_ampl = rfCavity.getAmp()
Ez = E0L*rf_ampl*self.axis_field_func.getY(z)
return Ez
def getRF_Cavity(self):
"""
Returns the parent RF Cavity.
"""
return self.getParam("rfCavity")
def track(self, paramsDict):
"""
The AxisFieldRF_Gap class implementation of
the AccNode class track(probe) method.
User have to track the design bunch first to setup all gaps arrival time.
"""
rfCavity = self.getRF_Cavity()
if(not rfCavity.isDesignSetUp()):
sequence = self.getSequence()
accLattice = sequence.getLinacAccLattice()
msg = "The AxisFieldRF_Gap class. "
msg += "You have to run trackDesign on the LinacAccLattice"
msg += "first to initialize all RF Cavities' phases!"
msg += os.linesep
if(accLattice != None):
msg = msg + "Lattice =" + accLattice.getName()
msg = msg + os.linesep
if(sequence != None):
msg = msg + "Sequence =" + sequence.getName()
msg = msg + os.linesep
msg = msg + "RF Cavity =" + rfCavity.getName()
msg = msg + os.linesep
msg = msg + "Name of element=" + self.getName()
msg = msg + os.linesep
msg = msg + "Type of element=" + self.getType()
msg = msg + os.linesep
orbitFinalize(msg)
#-----------------------------------------
nParts = self.getnParts()
index = self.getActivePartIndex()
part_length = self.getLength(index)
bunch = paramsDict["bunch"]
syncPart = bunch.getSyncParticle()
eKin_in = syncPart.kinEnergy()
E0L = 1.0e+9*self.getParam("E0L")
modePhase = self.baserf_gap.getParam("mode")*math.pi
frequency = rfCavity.getFrequency()
rf_ampl = rfCavity.getAmp()
arrival_time = syncPart.time()
designArrivalTime = rfCavity.getDesignArrivalTime()
phase_shift = rfCavity.getPhase() - rfCavity.getDesignPhase()
phase = rfCavity.getFirstGapEtnrancePhase() + phase_shift
#----------------------------------------
phase = math.fmod(frequency*(arrival_time - designArrivalTime)*2.0*math.pi + phase,2.0*math.pi)
if(index == 0):
self.part_pos = self.z_min
self.gap_phase_vs_z_arr = [[self.part_pos,phase],]
zm = self.part_pos
z0 = zm + part_length/2
zp = z0 + part_length/2
Em = E0L*rf_ampl*self.axis_field_func.getY(zm)
E0 = E0L*rf_ampl*self.axis_field_func.getY(z0)
Ep = E0L*rf_ampl*self.axis_field_func.getY(zp)
#---- advance the particle position
self.tracking_module.drift(bunch,part_length/2)
self.part_pos += part_length/2
#call rf gap model to track the bunch
time_middle_gap = syncPart.time() - arrival_time
delta_phase = math.fmod(2*math.pi*time_middle_gap*frequency,2.0*math.pi)
self.gap_phase_vs_z_arr.append([self.part_pos,phase+delta_phase])
#---- this part is the debugging ---START---
#eKin_out = syncPart.kinEnergy()
#s = "debug pos[mm]= %7.2f "%(self.part_pos*1000.)
#s += " ekin= %9.6f"%(syncPart.kinEnergy()*1000.)
#s += " phase = %9.2f "%(phaseNearTargetPhaseDeg((phase+delta_phase)*180./math.pi,0.))
#s += " dE= %9.6f "%((eKin_out-eKin_in)*1000.)
#print s
#---- this part is the debugging ---STOP---
self.cppGapModel.trackBunch(bunch,part_length/2,Em,E0,Ep,frequency,phase+delta_phase+modePhase)
self.tracking_module.drift(bunch,part_length/2)
#---- advance the particle position
self.part_pos += part_length/2
time_middle_gap = syncPart.time() - arrival_time
delta_phase = math.fmod(2*math.pi*time_middle_gap*frequency,2.0*math.pi)
self.gap_phase_vs_z_arr.append([self.part_pos,phase+delta_phase])
#---- this part is the debugging ---START---
#eKin_out = syncPart.kinEnergy()
#s = "debug pos[mm]= %7.2f "%(self.part_pos*1000.)
#s += " ekin= %9.6f"%(syncPart.kinEnergy()*1000.)
#s += " phase = %9.2f "%(phaseNearTargetPhaseDeg((phase+delta_phase)*180./math.pi,0.))
#s += " dE= %9.6f "%((eKin_out-eKin_in)*1000.)
#print s
#---- this part is the debugging ---STOP---
#---- Calculate the phase at the center
if(index == (nParts - 1)):
pos_old = self.gap_phase_vs_z_arr[0][0]
phase_gap = self.gap_phase_vs_z_arr[0][1]
ind_min = -1
for ind in range(1,len(self.gap_phase_vs_z_arr)):
[pos,phase_gap] = self.gap_phase_vs_z_arr[ind]
if(math.fabs(pos) >= math.fabs(pos_old)):
ind_min = ind -1
phase_gap = self.gap_phase_vs_z_arr[ind_min][1]
phase_gap = phaseNearTargetPhase(phase_gap,0.)
self.gap_phase_vs_z_arr[ind_min][1] = phase_gap
break
pos_old = pos
self.setGapPhase(phase_gap)
#---- wrap all gap part's phases around the central one
if(ind_min > 0):
for ind in range(ind_min-1,-1,-1):
[pos,phase_gap] = self.gap_phase_vs_z_arr[ind]
[pos,phase_gap1] = self.gap_phase_vs_z_arr[ind+1]
self.gap_phase_vs_z_arr[ind][1] = phaseNearTargetPhase(phase_gap,phase_gap1)
for ind in range(ind_min+1,len(self.gap_phase_vs_z_arr)):
[pos,phase_gap] = self.gap_phase_vs_z_arr[ind]
[pos,phase_gap1] = self.gap_phase_vs_z_arr[ind-1]
self.gap_phase_vs_z_arr[ind][1] = phaseNearTargetPhase(phase_gap,phase_gap1)
def trackDesign(self, paramsDict):
"""
The method is tracking the design synchronous particle through the RF Gap.
If the gap is a first gap in the cavity we put the arrival time as
a cavity parameter. The pair of the cavity design phase and this arrival time
at the first gap are used during the real bunch tracking.
"""
nParts = self.getnParts()
index = self.getActivePartIndex()
part_length = self.getLength(index)
bunch = paramsDict["bunch"]
syncPart = bunch.getSyncParticle()
eKin_in = syncPart.kinEnergy()
#---- parameter E0L is in GeV, but cppGapModel = RfGapThreePointTTF() uses fields in V/m
E0L = 1.0e+9*self.getParam("E0L")
modePhase = self.baserf_gap.getParam("mode")*math.pi
rfCavity = self.getRF_Cavity()
rf_ampl = rfCavity.getDesignAmp()
arrival_time = syncPart.time()
frequency = rfCavity.getFrequency()
phase = rfCavity.getFirstGapEtnrancePhase()
#---- calculate the entance phase
if(self.isFirstRFGap() and index == 0):
rfCavity.setDesignArrivalTime(arrival_time)
phase = self.__calculate_first_part_phase(bunch)
rfCavity.setFirstGapEtnrancePhase(phase)
rfCavity.setFirstGapEtnranceDesignPhase(phase)
rfCavity.setDesignSetUp(True)
rfCavity._setDesignPhase(rfCavity.getPhase())
rfCavity._setDesignAmp(rfCavity.getAmp())
#print "debug firs gap first part phase=",phase*180./math.pi," arr time=",arrival_time
else:
first_gap_arr_time = rfCavity.getDesignArrivalTime()
#print "debug name=",self.getName()," delta_phase=",frequency*(arrival_time - first_gap_arr_time)*360.0," phase=",phase*180/math.pi
phase = math.fmod(frequency*(arrival_time - first_gap_arr_time)*2.0*math.pi+phase,2.0*math.pi)
if(index == 0):
self.part_pos = self.z_min
self.gap_phase_vs_z_arr = [[self.part_pos,phase],]
#print "debug design name=",self.getName()," index=",index," pos=",self.part_pos," arr_time=",arrival_time," phase=",phase*180./math.pi," freq=",frequency
zm = self.part_pos
z0 = zm + part_length/2
zp = z0 + part_length/2
Em = E0L*rf_ampl*self.axis_field_func.getY(zm)
E0 = E0L*rf_ampl*self.axis_field_func.getY(z0)
Ep = E0L*rf_ampl*self.axis_field_func.getY(zp)
#---- advance the particle position
self.tracking_module.drift(bunch,part_length/2)
self.part_pos += part_length/2
#call rf gap model to track the bunch
time_middle_gap = syncPart.time() - arrival_time
delta_phase = math.fmod(2*math.pi*time_middle_gap*frequency,2.0*math.pi)
self.gap_phase_vs_z_arr.append([self.part_pos,phase+delta_phase])
#---- this part is the debugging ---START---
#eKin_out = syncPart.kinEnergy()
#s = "debug pos[mm]= %7.2f "%(self.part_pos*1000.)
#s += " ekin= %9.6f"%(syncPart.kinEnergy()*1000.)
#s += " phase = %9.2f "%(phaseNearTargetPhaseDeg((phase+delta_phase)*180./math.pi,0.))
#s += " dE= %9.6f "%((eKin_out-eKin_in)*1000.)
#print s
#---- this part is the debugging ---STOP---
self.cppGapModel.trackBunch(bunch,part_length/2,Em,E0,Ep,frequency,phase+delta_phase+modePhase)
self.tracking_module.drift(bunch,part_length/2)
#---- advance the particle position
self.part_pos += part_length/2
time_middle_gap = syncPart.time() - arrival_time
delta_phase = math.fmod(2*math.pi*time_middle_gap*frequency,2.0*math.pi)
self.gap_phase_vs_z_arr.append([self.part_pos,phase+delta_phase])
#---- this part is the debugging ---START---
#eKin_out = syncPart.kinEnergy()
#s = "debug pos[mm]= %7.2f "%(self.part_pos*1000.)
#s += " ekin= %9.6f"%(syncPart.kinEnergy()*1000.)
#s += " phase = %9.2f "%(phaseNearTargetPhaseDeg((phase+delta_phase)*180./math.pi,0.))
#s += " dE= %9.6f "%((eKin_out-eKin_in)*1000.)
#print s
#---- this part is the debugging ---STOP---
#---- Calculate the phase at the center
if(index == (nParts - 1)):
pos_old = self.gap_phase_vs_z_arr[0][0]
phase_gap = self.gap_phase_vs_z_arr[0][1]
ind_min = -1
for ind in range(1,len(self.gap_phase_vs_z_arr)):
[pos,phase_gap] = self.gap_phase_vs_z_arr[ind]
if(math.fabs(pos) >= math.fabs(pos_old)):
ind_min = ind -1
phase_gap = self.gap_phase_vs_z_arr[ind_min][1]
phase_gap = phaseNearTargetPhase(phase_gap,0.)
self.gap_phase_vs_z_arr[ind_min][1] = phase_gap
break
pos_old = pos
self.setGapPhase(phase_gap)
#---- wrap all gap part's phases around the central one
if(ind_min > 0):
for ind in range(ind_min-1,-1,-1):
[pos,phase_gap] = self.gap_phase_vs_z_arr[ind]
[pos,phase_gap1] = self.gap_phase_vs_z_arr[ind+1]
self.gap_phase_vs_z_arr[ind][1] = phaseNearTargetPhase(phase_gap,phase_gap1)
for ind in range(ind_min+1,len(self.gap_phase_vs_z_arr)):
[pos,phase_gap] = self.gap_phase_vs_z_arr[ind]
[pos,phase_gap1] = self.gap_phase_vs_z_arr[ind-1]
self.gap_phase_vs_z_arr[ind][1] = phaseNearTargetPhase(phase_gap,phase_gap1)
def calculate_first_part_phase(self,bunch_in):
"""
The privat method should be exposed to the AxisField_and_Quad_RF_Gap class
"""
phase_start = self.__calculate_first_part_phase(bunch_in)
return phase_start
def __calculate_first_part_phase(self,bunch_in):
rfCavity = self.getRF_Cavity()
#---- the design phase at the center of the RF gap
#---- (this is from a thin gap approach)
frequency = rfCavity.getFrequency()
modePhase = self.baserf_gap.getParam("mode")*math.pi
phase_cavity = rfCavity.getPhase()
#---- parameter E0L is in GeV, but cppGapModel = RfGapThreePointTTF() uses fields in V/m
E0L_local = 1.0e+9*rfCavity.getAmp()*self.getParam("E0L")
#---- we have to find the phase_start
#---- which is the phase at the distance z_min before the gap center
#---- z_min by defenition is negative
bunch = AxisFieldRF_Gap.static_test_bunch
bunch_in.copyEmptyBunchTo(bunch)
syncPart = bunch.getSyncParticle()
syncPart.time(0.)
eKin_init = syncPart.kinEnergy()
#print "debug eKin[MeV]= %9.5f"%(syncPart.kinEnergy()*1000.)
beta = syncPart.beta()
phase_adv = 2.0*math.pi*frequency*math.fabs(self.z_min)/(beta*speed_of_light)
#print "debug phase diff at start=",phase_adv*180./math.pi
phase_start = phaseNearTargetPhase(phase_cavity - phase_adv,0.)
#print "debug phase at start=",phase_start*180./math.pi
phase_cavity_new = phase_cavity + 10*self.phase_tolerance
while(math.fabs(phase_cavity_new-phase_cavity) > self.phase_tolerance*math.pi/180.):
bunch_in.copyEmptyBunchTo(bunch)
syncPart.time(0.)
syncPart.kinEnergy(eKin_init)
z_old = self.z_min
z = self.z_min + self.z_step
while(z < 0.):
if((z+ self.z_step) > 0.):
z = 0.
if(math.fabs(z - z_old) < self.z_tolerance):
break
half_step = (z - z_old)/2
zm = z_old
z0 = zm + half_step
zp = z0 + half_step
self.tracking_module.drift(bunch,half_step)
time_gap = syncPart.time()
delta_phase = 2*math.pi*time_gap*frequency
Em = E0L_local*self.axis_field_func.getY(zm)
E0 = E0L_local*self.axis_field_func.getY(z0)
Ep = E0L_local*self.axis_field_func.getY(zp)
#s = "debug z[mm]= %7.2f "%(z0*1000.)
#s += " ekin= %9.5f"%(syncPart.kinEnergy()*1000.)
#s += " phase = %9.2f "%(phaseNearTargetPhaseDeg((phase_start+delta_phase+modePhase)*180./math.pi,0.))
#print s
self.cppGapModel.trackBunch(bunch,half_step,Em,E0,Ep,frequency,phase_start+delta_phase+modePhase)
self.tracking_module.drift(bunch,half_step)
#time_gap = syncPart.time()
#delta_phase = 2*math.pi*time_gap*frequency
#s = "debug z[mm]= %7.2f "%(zp*1000.)
#s += " ekin= %9.5f"%(syncPart.kinEnergy()*1000.)
#s += " phase = %9.2f "%(phaseNearTargetPhaseDeg((phase_start+delta_phase+modePhase)*180./math.pi,0.))
#print s
z_old = z
z = z_old + self.z_step
time_gap = syncPart.time()
delta_phase =2*math.pi*time_gap*frequency
phase_cavity_new = phaseNearTargetPhase(phase_start+delta_phase,0.)
#s = " phase_diff = %8.4f "%(delta_phase*180./math.pi)
#s += " phase_cavity = %8.4f "%(phase_cavity*180./math.pi)
#s += " new = %8.4f "%(phase_cavity_new *180./math.pi)
#s += " phase_start = %8.4f "%(phase_start*180./math.pi)
#s += " eKin[MeV]= %9.5f "%(syncPart.kinEnergy()*1000.)
#s += " dE[MeV]= %9.6f "%(syncPart.kinEnergy()*1000. - 2.5)
#print "debug "+s
phase_start -= 0.8*(phase_cavity_new - phase_cavity)
#---- undo the last change in the while loop
phase_start += 0.8*(phase_cavity_new - phase_cavity)
#print "debug phase_start=",phase_start*180./math.pi
return phase_start
class AxisField_and_Quad_RF_Gap(AbstractRF_Gap):
"""
The class represents the part of the RF gap. It uses the part (longitudinally)
of the RF axis field that can be overlapped by quadrupole magnet field.
It is almost copy of the AxisFieldRF_Gap class, but it describes the part of
the whole RF gap because the axis field could cover the dipole correctors or
BPMs, and it has to be cut in peaces. It also could overlap the neighboring
quadrupoles, therefore it should account for the tracking inside quad fields.
The method setAsFirstRFGap(True/False) will be called by RF cavity.
User have to provide the instance of the AxisFieldRF_Gap at the constructor.
The instance of this class has the axis field for the whole gap.
"""
def __init__(self, axis_field_rf_gap):
"""
Constructor for the axis field RF gap.
The axis_field_rf_gap is the instance of the AbstractRF_Gap class.
E0L parameter is in GeV. Phases are in radians.
"""
AbstractRF_Gap.__init__(self, axis_field_rf_gap.getName())
self.setType("GAP&Q")
self.axis_field_rf_gap = axis_field_rf_gap
self.addParam("E0TL", self.axis_field_rf_gap.getParam("E0TL"))
self.addParam("mode", self.axis_field_rf_gap.getParam("mode"))
self.addParam("gap_phase",
self.axis_field_rf_gap.getParam("gap_phase"))
self.addParam("rfCavity", self.axis_field_rf_gap.getParam("rfCavity"))
self.addParam("E0L", self.axis_field_rf_gap.getParam("E0L"))
self.addParam("EzFile", self.axis_field_rf_gap.getParam("EzFile"))
self.setPosition(self.axis_field_rf_gap.getPosition())
#---- aperture parameters
if (axis_field_rf_gap.hasParam("aperture")
and axis_field_rf_gap.hasParam("aprt_type")):
self.addParam("aperture", axis_field_rf_gap.getParam("aperture"))
self.addParam("aprt_type", axis_field_rf_gap.getParam("aprt_type"))
#---- axis field related parameters
self.z_step = 0.01
self.z_min = 0.
self.z_max = 0.
#---- gap_phase_vs_z_arr keeps [pos,phase] pairs after the tracking
self.gap_phase_vs_z_arr = []
#---- The position of the particle during the run.
#---- It is used for the path length accounting.
self.part_pos = 0.
#---- The RF gap model - three points model
self.cppGapModel = RfGapThreePointTTF()
#---- If we going to use the longitudinal magnetic field component of quad
self.useLongField = False
#---- quadrupole field sources
#----quads_fields_arr is an array of [quad, fieldFunc, z_center_of_field]
self.quads_fields_arr = []
#---- If it is true then the this tracking will be in the reversed lattice
self.reversed_lattice = False
def setLinacTracker(self, switch=True):
"""
This method will switch RF gap model to slower one where transformations
coefficients are calculated for each particle in the bunch.
"""
BaseLinacNode.setLinacTracker(self, switch)
AbstractRF_Gap.setLinacTracker(self, switch)
if (switch):
self.cppGapModel = RfGapThreePointTTF_slow()
else:
self.cppGapModel = RfGapThreePointTTF()
def setUseLongitudinalFieldOfQuad(self, use):
"""
If we going to use the longitudinal magnetic field component of quad
"""
self.useLongField = use
def getUseLongitudinalFieldOfQuad(self):
"""
If we going to use the longitudinal magnetic field component of quad
"""
return self.useLongField
def getAxisFieldRF_Gap(self):
"""
It returns the AxisFieldRF_Gap instance for this gap.
"""
return self.axis_field_rf_gap
def getBaseRF_Gap(self):
"""
It returns the BaseRF_Gap instance for this gap.
"""
return self.axis_field_rf_gap.baserf_gap
def reverseOrderNodeSpecific(self):
"""
This method is used for a lattice reversal and a bunch backtracking
This is a node type specific method. The implementation of the abstract
method of AccNode class from the top level lattice package.
"""
self.reversed_lattice = not self.reversed_lattice
#---- Here the order of quads does not matter
for quad_ind in range(len(self.quads_fields_arr)):
[quad, fieldFunc,
z_center_of_field] = self.quads_fields_arr[quad_ind]
self.quads_fields_arr[quad_ind][2] = -z_center_of_field
(self.z_min, self.z_max) = (-self.z_max, -self.z_min)
def isNodeInReversedLattice(self):
"""
Returns True if this node in the reversed lattice or False if it otherwise.
"""
return self.reversed_lattice
def addQuad(self, quad, fieldFunc, z_center_of_field):
"""
Adds the quad with the field function and the position.
The position of the quad is relative to the center of
the parent rf gap node.
"""
self.quads_fields_arr.append([quad, fieldFunc, z_center_of_field])
def getQuads(self):
"""
Returns the list of quads in this node.
"""
quads = []
for [quad, fieldFunc, z_center_of_field] in self.quads_fields_arr:
quads.append(quad)
return quads
def getPosAndQuad_Arr(self):
"""
Return the array with pairs: the quad and the position of its center.
"""
quad_arr = []
for [quad, fieldFunc, z_center_of_field] in self.quads_fields_arr:
quad_arr.append([quad, z_center_of_field])
return quad_arr
def getTotalField(self, z_from_center):
"""
Returns the combined field of all overlapping quads.
z_from_center - is a distance from the center of the parent RF gap node.
"""
z = z_from_center
G = 0.
if (z < self.z_min or z > self.z_max): return G
for [quad, fieldFunc, z_center_of_field] in self.quads_fields_arr:
if (fieldFunc != None):
gl = quad.getParam("dB/dr") * quad.getLength()
G += gl * fieldFunc.getFuncValue(z - z_center_of_field)
else:
G += quad.getTotalField(z - z_center_of_field)
return G
def getTotalFieldDerivative(self, z_from_center):
"""
Returns the combined derivative of the field of all overlapping quads.
z_from_center - is a distance from the center of the parent RF gap node.
"""
z = z_from_center
GP = 0.
if (z < self.z_min or z > self.z_max): return GP
for [quad, fieldFunc, z_center_of_field] in self.quads_fields_arr:
if (fieldFunc != None):
gl = quad.getParam("dB/dr") * quad.getLength()
GP += gl * fieldFunc.getFuncDerivative(z - z_center_of_field)
else:
GP += 0.
return GP
def getZ_Step(self):
"""
Returns the longitudinal step during the tracking.
"""
return self.z_step
def setZ_Step(self, z_step):
if (self.axis_field_rf_gap.axis_field_func == None):
msg = "Class AxisFieldRF_Gap: You have to get the axis field from a file first!"
msg += os.linesep
msg += "Call readAxisFieldFile(dir_location,file_name) method first!"
msg += "Stop."
orbitFinalize(msg)
length = self.getLength()
nParts = int(length * 1.0000001 / z_step)
if (nParts < 1): nParts = 1
self.z_step = length / nParts
#---- this will set the even distribution of the lengths between parts
self.setnParts(nParts)
def getZ_Min_Max(self):
"""
Returns the tuple (z_min,z_max) with the limits of the axis field.
These parameters define the length of the node. The center of the node
is at 0.
"""
return (self.z_min, self.z_max)
def setZ_Min_Max(self, z_min, z_max):
"""
Sets the actual longitudinal sizes of the node. It is used for small correction
of the length to avoid fields overlapping from neighbouring gaps.
"""
self.z_min = z_min
self.z_max = z_max
length = self.z_max - self.z_min
self.setLength(length)
self.setZ_Step(self.z_step)
def getEzFiled(self, z):
"""
Returns the Ez field on the axis of the RF gap in V/m.
"""
rfCavity = self.getRF_Cavity()
E0L = 1.0e+9 * self.getParam("E0L")
rf_ampl = rfCavity.getAmp()
Ez = self.getEzFiledInternal(z, rfCavity, E0L, rf_ampl)
return Ez
def getEzFiledInternal(self, z, rfCavity, E0L, rf_ampl):
"""
Returns the Ez field on the axis of the RF gap in V/m.
"""
if (self.reversed_lattice): z *= -1
Ez = E0L * rf_ampl * self.axis_field_rf_gap.axis_field_func.getY(z)
return Ez
def getRF_Cavity(self):
"""
Returns the parent RF Cavity.
"""
return self.getParam("rfCavity")
def track(self, paramsDict):
"""
The AxisFieldRF_Gap class implementation of
the AccNode class track(probe) method.
User have to track the design bunch first to setup all gaps arrival time.
"""
rfCavity = self.getRF_Cavity()
if (not rfCavity.isDesignSetUp()):
sequence = self.getSequence()
accLattice = sequence.getLinacAccLattice()
msg = "The AxisFieldRF_Gap class. "
msg += "You have to run trackDesign on the LinacAccLattice"
msg += "first to initialize all RF Cavities' phases!"
msg += os.linesep
if (accLattice != None):
msg = msg + "Lattice =" + accLattice.getName()
msg = msg + os.linesep
if (sequence != None):
msg = msg + "Sequence =" + sequence.getName()
msg = msg + os.linesep
msg = msg + "RF Cavity =" + rfCavity.getName()
msg = msg + os.linesep
msg = msg + "Name of element=" + self.getName()
msg = msg + os.linesep
msg = msg + "Type of element=" + self.getType()
msg = msg + os.linesep
orbitFinalize(msg)
#-----------------------------------------
nParts = self.getnParts()
index = self.getActivePartIndex()
part_length = self.getLength(index)
bunch = paramsDict["bunch"]
syncPart = bunch.getSyncParticle()
eKin_in = syncPart.kinEnergy()
momentum = syncPart.momentum()
E0L = 1.0e+9 * self.getParam("E0L")
modePhase = self.axis_field_rf_gap.baserf_gap.getParam(
"mode") * math.pi
frequency = rfCavity.getFrequency()
rf_ampl = rfCavity.getAmp()
arrival_time = syncPart.time()
designArrivalTime = rfCavity.getDesignArrivalTime()
phase_shift = rfCavity.getPhase() - rfCavity.getDesignPhase()
phase = rfCavity.getFirstGapEtnrancePhase() + phase_shift
#----------------------------------------
phase = math.fmod(
frequency * (arrival_time - designArrivalTime) * 2.0 * math.pi +
phase, 2.0 * math.pi)
if (index == 0):
self.part_pos = self.z_min
self.gap_phase_vs_z_arr = [
[self.part_pos, phase],
]
zm = self.part_pos
z0 = zm + part_length / 2
zp = z0 + part_length / 2
Em = self.getEzFiledInternal(zm, rfCavity, E0L, rf_ampl)
E0 = self.getEzFiledInternal(z0, rfCavity, E0L, rf_ampl)
Ep = self.getEzFiledInternal(zp, rfCavity, E0L, rf_ampl)
#------- track through a quad
G = self.getTotalField((zm + z0) / 2)
GP = 0.
if (self.useLongField == True):
GP = self.getTotalFieldDerivative((zm + z0) / 2)
if (abs(G) != 0.):
kq = G / (3.335640952 * momentum)
#------- track through a quad
step = part_length / 2
self.tracking_module.quad1(bunch, step / 4.0, kq)
self.tracking_module.quad2(bunch, step / 2.0)
self.tracking_module.quad1(bunch, step / 2.0, kq)
self.tracking_module.quad2(bunch, step / 2.0)
self.tracking_module.quad1(bunch, step / 4.0, kq)
if (abs(GP) != 0.):
kqP = GP / (3.335640952 * momentum)
self.tracking_module.quad3(bunch, step, kqP)
else:
self.tracking_module.drift(bunch, part_length / 2)
self.part_pos += part_length / 2
#call rf gap model to track the bunch
time_middle_gap = syncPart.time() - arrival_time
delta_phase = math.fmod(2 * math.pi * time_middle_gap * frequency,
2.0 * math.pi)
self.gap_phase_vs_z_arr.append([self.part_pos, phase + delta_phase])
#---- this part is the debugging ---START---
#eKin_out = syncPart.kinEnergy()
#s = "debug pos[mm]= %7.2f "%(self.part_pos*1000.)
#s += " ekin= %9.6f"%(syncPart.kinEnergy()*1000.)
#s += " phase = %9.2f "%(phaseNearTargetPhaseDeg((phase+delta_phase)*180./math.pi,0.))
#s += " dE= %9.6f "%((eKin_out-eKin_in)*1000.)
#print s
#---- this part is the debugging ---STOP---
self.cppGapModel.trackBunch(bunch, part_length / 2, Em, E0, Ep,
frequency, phase + delta_phase + modePhase)
#------- track through a quad
G = self.getTotalField((z0 + zp) / 2)
GP = 0.
if (self.useLongField == True):
GP = self.getTotalFieldDerivative((z0 + zp) / 2)
if (abs(G) != 0.):
kq = G / (3.335640952 * momentum)
step = part_length / 2
self.tracking_module.quad1(bunch, step / 4.0, kq)
self.tracking_module.quad2(bunch, step / 2.0)
self.tracking_module.quad1(bunch, step / 2.0, kq)
self.tracking_module.quad2(bunch, step / 2.0)
self.tracking_module.quad1(bunch, step / 4.0, kq)
if (abs(GP) != 0.):
kqP = GP / (3.335640952 * momentum)
self.tracking_module.quad3(bunch, step, kqP)
else:
self.tracking_module.drift(bunch, part_length / 2)
#---- advance the particle position
self.part_pos += part_length / 2
time_middle_gap = syncPart.time() - arrival_time
delta_phase = math.fmod(2 * math.pi * time_middle_gap * frequency,
2.0 * math.pi)
self.gap_phase_vs_z_arr.append([self.part_pos, phase + delta_phase])
#---- this part is the debugging ---START---
#eKin_out = syncPart.kinEnergy()
#s = "debug pos[mm]= %7.2f "%(self.part_pos*1000.)
#s += " ekin= %9.6f"%(syncPart.kinEnergy()*1000.)
#s += " phase = %9.2f "%(phaseNearTargetPhaseDeg((phase+delta_phase)*180./math.pi,0.))
#s += " dE= %9.6f "%((eKin_out-eKin_in)*1000.)
#print s
#---- this part is the debugging ---STOP---
#---- Calculate the phase at the center
if (index == (nParts - 1)):
pos_old = self.gap_phase_vs_z_arr[0][0]
phase_gap = self.gap_phase_vs_z_arr[0][1]
ind_min = -1
for ind in range(1, len(self.gap_phase_vs_z_arr)):
[pos, phase_gap] = self.gap_phase_vs_z_arr[ind]
if (math.fabs(pos) >= math.fabs(pos_old)):
ind_min = ind - 1
phase_gap = self.gap_phase_vs_z_arr[ind_min][1]
phase_gap = phaseNearTargetPhase(phase_gap, 0.)
self.gap_phase_vs_z_arr[ind_min][1] = phase_gap
break
pos_old = pos
self.setGapPhase(phase_gap)
#---- wrap all gap part's phases around the central one
if (ind_min > 0):
for ind in range(ind_min - 1, -1, -1):
[pos, phase_gap] = self.gap_phase_vs_z_arr[ind]
[pos, phase_gap1] = self.gap_phase_vs_z_arr[ind + 1]
self.gap_phase_vs_z_arr[ind][1] = phaseNearTargetPhase(
phase_gap, phase_gap1)
for ind in range(ind_min + 1, len(self.gap_phase_vs_z_arr)):
[pos, phase_gap] = self.gap_phase_vs_z_arr[ind]
[pos, phase_gap1] = self.gap_phase_vs_z_arr[ind - 1]
self.gap_phase_vs_z_arr[ind][1] = phaseNearTargetPhase(
phase_gap, phase_gap1)
def trackDesign(self, paramsDict):
"""
The method is tracking the design synchronous particle through the RF Gap.
If the gap is a first gap in the cavity we put the arrival time as
a cavity parameter. The pair of the cavity design phase and this arrival time
at the first gap are used during the real bunch tracking.
"""
nParts = self.getnParts()
index = self.getActivePartIndex()
part_length = self.getLength(index)
bunch = paramsDict["bunch"]
syncPart = bunch.getSyncParticle()
eKin_in = syncPart.kinEnergy()
#---- parameter E0L is in GeV, but cppGapModel = RfGapThreePointTTF() uses fields in V/m
E0L = 1.0e+9 * self.getParam("E0L")
modePhase = self.axis_field_rf_gap.baserf_gap.getParam(
"mode") * math.pi
rfCavity = self.getRF_Cavity()
rf_ampl = rfCavity.getDesignAmp()
arrival_time = syncPart.time()
frequency = rfCavity.getFrequency()
phase = rfCavity.getFirstGapEtnrancePhase()
#---- calculate the entance phase
if (self.isFirstRFGap() and index == 0):
rfCavity.setDesignArrivalTime(arrival_time)
phase = self.axis_field_rf_gap.calculate_first_part_phase(bunch)
rfCavity.setFirstGapEtnrancePhase(phase)
rfCavity.setFirstGapEtnranceDesignPhase(phase)
rfCavity.setDesignSetUp(True)
rfCavity._setDesignPhase(rfCavity.getPhase())
rfCavity._setDesignAmp(rfCavity.getAmp())
#print "debug firs gap first part phase=",phase*180./math.pi," arr time=",arrival_time
else:
first_gap_arr_time = rfCavity.getDesignArrivalTime()
#print "debug name=",self.getName()," delta_phase=",frequency*(arrival_time - first_gap_arr_time)*360.0," phase=",phase*180/math.pi
phase = math.fmod(
frequency *
(arrival_time - first_gap_arr_time) * 2.0 * math.pi + phase,
2.0 * math.pi)
#print "debug design name=",self.getName()," arr_time=",arrival_time," phase=",phase*180./math.pi," E0TL=",E0TL*1.0e+3," freq=",frequency
if (index == 0):
self.part_pos = self.z_min
self.gap_phase_vs_z_arr = [
[self.part_pos, phase],
]
zm = self.part_pos
z0 = zm + part_length / 2
zp = z0 + part_length / 2
Em = self.getEzFiledInternal(zm, rfCavity, E0L, rf_ampl)
E0 = self.getEzFiledInternal(z0, rfCavity, E0L, rf_ampl)
Ep = self.getEzFiledInternal(zp, rfCavity, E0L, rf_ampl)
#---- advance the particle position
self.tracking_module.drift(bunch, part_length / 2)
self.part_pos += part_length / 2
#call rf gap model to track the bunch
time_middle_gap = syncPart.time() - arrival_time
delta_phase = math.fmod(2 * math.pi * time_middle_gap * frequency,
2.0 * math.pi)
self.gap_phase_vs_z_arr.append([self.part_pos, phase + delta_phase])
#---- this part is the debugging ---START---
#eKin_out = syncPart.kinEnergy()
#s = "debug pos[mm]= %7.2f "%(self.part_pos*1000.)
#s += " ekin= %9.6f"%(syncPart.kinEnergy()*1000.)
#s += " phase = %9.2f "%(phaseNearTargetPhaseDeg((phase+delta_phase)*180./math.pi,0.))
#s += " dE= %9.6f "%((eKin_out-eKin_in)*1000.)
#print s
#---- this part is the debugging ---STOP---
self.cppGapModel.trackBunch(bunch, part_length / 2, Em, E0, Ep,
frequency, phase + delta_phase + modePhase)
self.tracking_module.drift(bunch, part_length / 2)
#---- advance the particle position
self.part_pos += part_length / 2
time_middle_gap = syncPart.time() - arrival_time
delta_phase = math.fmod(2 * math.pi * time_middle_gap * frequency,
2.0 * math.pi)
self.gap_phase_vs_z_arr.append([self.part_pos, phase + delta_phase])
#---- this part is the debugging ---START---
#eKin_out = syncPart.kinEnergy()
#s = "debug pos[mm]= %7.2f "%(self.part_pos*1000.)
#s += " ekin= %9.6f"%(syncPart.kinEnergy()*1000.)
#s += " phase = %9.2f "%(phaseNearTargetPhaseDeg((phase+delta_phase)*180./math.pi,0.))
#s += " dE= %9.6f "%((eKin_out-eKin_in)*1000.)
#print s
#---- this part is the debugging ---STOP---
#---- Calculate the phase at the center
if (index == (nParts - 1)):
pos_old = self.gap_phase_vs_z_arr[0][0]
phase_gap = self.gap_phase_vs_z_arr[0][1]
ind_min = -1
for ind in range(1, len(self.gap_phase_vs_z_arr)):
[pos, phase_gap] = self.gap_phase_vs_z_arr[ind]
if (math.fabs(pos) >= math.fabs(pos_old)):
ind_min = ind - 1
phase_gap = self.gap_phase_vs_z_arr[ind_min][1]
phase_gap = phaseNearTargetPhase(phase_gap, 0.)
self.gap_phase_vs_z_arr[ind_min][1] = phase_gap
break
pos_old = pos
self.setGapPhase(phase_gap)
#---- wrap all gap part's phases around the central one
if (ind_min > 0):
for ind in range(ind_min - 1, -1, -1):
[pos, phase_gap] = self.gap_phase_vs_z_arr[ind]
[pos, phase_gap1] = self.gap_phase_vs_z_arr[ind + 1]
self.gap_phase_vs_z_arr[ind][1] = phaseNearTargetPhase(
phase_gap, phase_gap1)
for ind in range(ind_min + 1, len(self.gap_phase_vs_z_arr)):
[pos, phase_gap] = self.gap_phase_vs_z_arr[ind]
[pos, phase_gap1] = self.gap_phase_vs_z_arr[ind - 1]
self.gap_phase_vs_z_arr[ind][1] = phaseNearTargetPhase(
phase_gap, phase_gap1)