From 8a09649dd88883d34d88f886791664fcd7e26411 Mon Sep 17 00:00:00 2001
From: Alexis Gamelin <alexis.gamelin@synchrotron-soleil.fr>
Date: Thu, 16 May 2024 17:20:51 +0200
Subject: [PATCH] Document modifications
---
mbtrack2/impedance/wakefield.py | 16 ++++++++++---
mbtrack2/tracking/rf.py | 37 ++++++++++++++++---------------
mbtrack2/tracking/synchrotron.py | 25 ++++++++++++++++++---
mbtrack2/utilities/beamloading.py | 10 +++++++++
4 files changed, 64 insertions(+), 24 deletions(-)
diff --git a/mbtrack2/impedance/wakefield.py b/mbtrack2/impedance/wakefield.py
index ee83e57..5ef7bea 100644
--- a/mbtrack2/impedance/wakefield.py
+++ b/mbtrack2/impedance/wakefield.py
@@ -600,6 +600,8 @@ class Impedance(ComplexData):
Return a WakeFunction object from the impedance data.
plot()
Plot the impedance data.
+ to_pycolleff()
+ Convenience method to export impedance to pycolleff.
"""
def __init__(self,
@@ -782,7 +784,18 @@ class Impedance(ComplexData):
return ax
def to_pycolleff(self):
+ """
+ Convenience method to export impedance to pycolleff.
+ Only implemented for longitudinal impedance.
+
+ Returns
+ -------
+ imp : pycolleff.longitudinal_equilibrium.ImpedanceSource
+ pycolleff ImpedanceSource object
+ """
+ # pycolleff is a soft dependency
from pycolleff.longitudinal_equilibrium import ImpedanceSource
+ # avoid circular import
from mbtrack2.utilities.misc import double_sided_impedance
imp = ImpedanceSource()
if self.component_type == "long":
@@ -793,10 +806,7 @@ class Impedance(ComplexData):
else:
raise NotImplementedError()
- # Methods: Impedance or Wake
imp.calc_method = ImpedanceSource.Methods.ImpedanceDFT
-
- # Device type: Active of Passive
imp.active_passive = ImpedanceSource.ActivePassive.Passive
return imp
diff --git a/mbtrack2/tracking/rf.py b/mbtrack2/tracking/rf.py
index 149b03e..41284a1 100644
--- a/mbtrack2/tracking/rf.py
+++ b/mbtrack2/tracking/rf.py
@@ -191,6 +191,8 @@ class CavityResonator():
Force feedback update from current CavityResonator parameters.
sample_voltage()
Sample the voltage seen by a zero charge particle during an RF period.
+ to_pycolleff()
+ Convenience method to export a CavityResonator to pycolleff.
References
----------
@@ -1143,6 +1145,22 @@ class CavityResonator():
return pos, voltage_rec
def to_pycolleff(self, Impedance=True):
+ """
+ Convenience method to export a CavityResonator to pycolleff.
+
+ Parameters
+ ----------
+ Impedance : bool, optional
+ If True, export as impedance (i.e. ImpedanceSource.Methods.ImpedanceDFT).
+ If False, export as wake (i.e. ImpedanceSource.Methods.Wake).
+ Default is True.
+
+ Returns
+ -------
+ cav : pycolleff ImpedanceSource object
+
+ """
+ # pycolleff is a soft dependency
from pycolleff.longitudinal_equilibrium import ImpedanceSource
cav = ImpedanceSource()
@@ -1156,24 +1174,7 @@ class CavityResonator():
if self.Vg != 0:
cav.active_passive = ImpedanceSource.ActivePassive.Active
if Impedance:
- cav.calc_method = ImpedanceSource.Methods.ImpedanceDFT
- # Define PID transfer function for control loop
- def pid_transfer_func(w, wrf, gain=1, kp=1, ki=1, kd=0, delay=0):
- phase = wrf * delay
- exp_delay = np.exp(-1j * delay * w)
- exp_phase = np.exp(1j * phase)
- eps = 1e-16
- pid_ctrl = kp + ki / 1j / (w - wrf + eps) + kd * 1j * (w - wrf)
- transfer = gain * pid_ctrl * exp_delay * exp_phase
- return transfer
-
- delay = 1.9e-6
- ki = 0.01
- kp = 2.96e-6
- kd = 0
- cav.loop_ctrl_ang_freq = self.ring.omega1
- cav.loop_ctrl_transfer = partial(pid_transfer_func, kp=kp, ki=ki, delay=delay)
- # cav.loop_ctrl_transfer = partial(pid_transfer_func, kp=0, ki=1, delay=0)
+ raise NotImplementedError()
else:
cav.calc_method = ImpedanceSource.Methods.Wake
else:
diff --git a/mbtrack2/tracking/synchrotron.py b/mbtrack2/tracking/synchrotron.py
index 8a4dd02..fa37923 100644
--- a/mbtrack2/tracking/synchrotron.py
+++ b/mbtrack2/tracking/synchrotron.py
@@ -116,6 +116,8 @@ class Synchrotron:
single or multi-harmonic RF systems.
to_pyat(Vrf)
Return a pyAT simple_ring element from the Synchrotron element data.
+ to_pycolleff(I0, Vrf, bunch_number)
+ Return a pycolleff Ring element from the Synchrotron element data.
"""
def __init__(self, h, optics, particle, **kwargs):
@@ -585,7 +587,26 @@ class Synchrotron:
TimeLag=TimeLag)
return at_simple_ring
- def to_pycolleff(self, I0, Vrf, bunch_number, delta=0):
+ def to_pycolleff(self, I0, Vrf, bunch_number):
+ """
+ Return a pycolleff Ring element from the Synchrotron element data.
+
+ Parameters
+ ----------
+ I0 : float
+ Beam current in [A].
+ Vrf : float
+ RF voltage in [V].
+ bunch_number : int
+ Total number of bunches filled.
+
+ Returns
+ -------
+ ring : pycolleff.colleff.Ring
+ pycolleff Ring object.
+
+ """
+ # pycolleff is a soft dependency
from pycolleff.colleff import Ring
ring = Ring()
@@ -599,7 +620,6 @@ class Synchrotron:
ring.chromy = self.chro[1] # vertical chromaticity
ring.harm_num = self.h # harmonic Number
ring.num_bun = bunch_number # number of bunches filled
-
ring.total_current = I0 # total current [A]
ring.sync_tune = self.synchrotron_tune(Vrf) # synchrotron tune
ring.espread = self.sigma_delta
@@ -609,7 +629,6 @@ class Synchrotron:
ring.dampte = self.tau[2] # [s]
ring.en_lost_rad = self.U0 # [eV]
ring.gap_voltage = Vrf # [V]
- ring.delta_HC = delta
return ring
diff --git a/mbtrack2/utilities/beamloading.py b/mbtrack2/utilities/beamloading.py
index 041741b..b51554f 100644
--- a/mbtrack2/utilities/beamloading.py
+++ b/mbtrack2/utilities/beamloading.py
@@ -397,6 +397,16 @@ class BeamLoadingEquilibrium():
@property
def R_factor(self):
+ """
+ Touschek lifetime ratio as defined in [1].
+
+ Reference
+ ---------
+ [1] : Byrd, J. M., and M. Georgsson. "Lifetime increase using passive
+ harmonic cavities in synchrotron light sources." Physical Review
+ Special Topics-Accelerators and Beams 4.3 (2001): 030701.
+
+ """
rho0 = gaussian_bunch(self.tau0, self.ring.sigma_0)/c
R = trapz(rho0**2, self.tau0)/trapz(self.rho0**2, self.tau0)
return R
--
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