diff --git a/tracking/rf.py b/tracking/rf.py
index b1fc6056920b7451c743c087d57fc5db73cb4063..3194e75cff031ea3a68d55dbd8032a344acbe521 100644
--- a/tracking/rf.py
+++ b/tracking/rf.py
@@ -169,14 +169,13 @@ class CavityResonator():
def init_tracking(self, beam):
"""
- Initialization of the tracking
+ Initialization of the tracking.
Parameters
----------
beam : Beam object
"""
-
if beam.mpi_switch:
self.bunch_index = beam.mpi.bunch_num # Number of the tracked bunch in this processor
@@ -185,10 +184,19 @@ class CavityResonator():
self.tracking = True
self.nturn = 0
- def track(self, beam, ref_frame="beam"):
- """version type mbtrack + formule analytique
+ def track(self, beam):
+ """
+ Track a Beam object through the CavityResonator object.
- phasor is given at t=0 synchronous particle of the bunch 0
+ Can be used with or without mpi.
+
+ The beam phasor is given at t=0 (synchronous particle) of the first
+ non empty bunch.
+
+ Parameters
+ ----------
+ beam : Beam object
+
"""
if self.tracking is False:
@@ -200,7 +208,6 @@ class CavityResonator():
if beam.mpi_switch:
# get shared bunch profile for current bunch
- bins = beam.mpi.bins_all[j]
center = beam.mpi.center_all[j]
profile = beam.mpi.profile_all[j]
bin_length = center[1]-center[0]
@@ -216,19 +223,18 @@ class CavityResonator():
energy_change = bunch["tau"]*0
- # phasor is given at t=0 synchronous particle of the bunch
- # remove part of beam phasor decay to be at the start of the binning
- self.phasor_decay(bins[0], ref_frame=ref_frame)
+ # remove part of beam phasor decay to be at the start of the binning (=bins[0])
+ self.phasor_decay(center[0] - bin_length/2, ref_frame="beam")
if index != self.bunch_index:
- self.phasor_evol(profile, bin_length, charge_per_mp, ref_frame=ref_frame)
+ self.phasor_evol(profile, bin_length, charge_per_mp, ref_frame="beam")
else:
# modify beam phasor
for i, center0 in enumerate(center):
mp_per_bin = profile[i]
if mp_per_bin == 0:
- self.phasor_decay(bin_length, ref_frame=ref_frame)
+ self.phasor_decay(bin_length, ref_frame="beam")
continue
ind = (sorted_index == i)
@@ -239,22 +245,32 @@ class CavityResonator():
energy_change[ind] = Vtot / self.ring.E0
self.beam_phasor -= 2*charge_per_mp*self.loss_factor*mp_per_bin
- self.phasor_decay(bin_length, ref_frame=ref_frame)
-
- self.phasor_decay(-1*bins[-1], ref_frame=ref_frame)
- self.phasor_decay(self.distance[index] * self.ring.T1, ref_frame=ref_frame)
+ self.phasor_decay(bin_length, ref_frame="beam")
+
+ # phasor decay to be at t=0 of the current bunch (=-1*bins[-1])
+ self.phasor_decay(-1 * (center[-1] + bin_length/2), ref_frame="beam")
+ # phasor decay to be at t=0 of the next bunch
+ self.phasor_decay( (self.distance[index] * self.ring.T1), ref_frame="beam")
if index == self.bunch_index:
# apply kick
bunch["delta"] += energy_change
- bunch.energy_change = energy_change
self.nturn += 1
def init_phasor(self, beam):
- """version type mbtrack + formule analytique"""
+ """
+ Initialize the beam phasor for a given beam distribution.
+ Follow the same steps as the track method but in the "rf" reference
+ frame and without any modifications on the beam.
+
+ Parameters
+ ----------
+ beam : Beam object
+
+ """
if self.tracking is False:
self.init_tracking(beam)
@@ -267,7 +283,6 @@ class CavityResonator():
if beam.mpi_switch:
# get shared bunch profile for current bunch
- bins = beam.mpi.bins_all[j]
center = beam.mpi.center_all[j]
profile = beam.mpi.profile_all[j]
bin_length = center[1]-center[0]
@@ -278,11 +293,10 @@ class CavityResonator():
bin_length = center[1]-center[0]
charge_per_mp = bunch.charge_per_mp
- # phasor is given at t=0 synchronous particle of the bunch
- # remove part of beam phasor decay to be at the start of the binning
- self.phasor_decay(bins[0], ref_frame="rf")
+ self.phasor_decay(center[0] - bin_length/2, ref_frame="rf")
self.phasor_evol(profile, bin_length, charge_per_mp, ref_frame="rf")
- self.phasor_decay( (self.distance[index] * self.ring.T1) - bins[-1], ref_frame="rf")
+ self.phasor_decay(-1 * (center[-1] + bin_length/2), ref_frame="rf")
+ self.phasor_decay( (self.distance[index] * self.ring.T1), ref_frame="rf")
def phasor_decay(self, time, ref_frame="beam"):
"""
@@ -293,6 +307,8 @@ class CavityResonator():
----------
time : float
Time span in [s], can be positive or negative.
+ ref_frame : string, optional
+ Reference frame to be used, can be "beam" or "rf".
"""
if ref_frame == "beam":
@@ -305,6 +321,8 @@ class CavityResonator():
def phasor_evol(self, profile, bin_length, charge_per_mp, ref_frame="beam"):
"""
Compute the beam phasor evolution during the crossing of a bunch.
+
+ Assume that the phasor decay happens before the beam loading.
Parameters
----------
@@ -314,6 +332,9 @@ class CavityResonator():
Length of a bin in [s].
charge_per_mp : float
Charge per macro-particle in [C].
+ ref_frame : string, optional
+ Reference frame to be used, can be "beam" or "rf".
+
"""
if ref_frame == "beam":
delta = self.wr