From 6cb37ed6cb80fd01e69ab0306f1479858395616a Mon Sep 17 00:00:00 2001
From: Watanyu Foosang <watanyu.f@gmail.com>
Date: Thu, 22 Apr 2021 18:21:36 +0200
Subject: [PATCH] Fix ADTS handling algorithm and add its docstring
---
tracking/element.py | 15 ++++++++++-----
tracking/synchrotron.py | 13 +++++++++++++
2 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/tracking/element.py b/tracking/element.py
index 4fa5aea..de37ca8 100644
--- a/tracking/element.py
+++ b/tracking/element.py
@@ -154,10 +154,15 @@ class TransverseMap(Element):
self.dispersion = self.ring.optics.local_dispersion
self.phase_advance = self.ring.tune[0:2]*2*np.pi
- if self.ring.adts.all() == 0:
- self.adts_option = False
- else:
+ if self.ring.adts is not None:
self.adts_option = True
+ self.adts_poly = np.array([np.poly1d(self.ring.adts[0]),
+ np.poly1d(self.ring.adts[1]),
+ np.poly1d(self.ring.adts[2]),
+ np.poly1d(self.ring.adts[3])])
+
+ else:
+ self.adts_option = False
@Element.parallel
def track(self, bunch):
@@ -174,10 +179,10 @@ class TransverseMap(Element):
# Compute phase advance which depends on energy via chromaticity and ADTS
if self.adts_option is True:
phase_advance_x = self.phase_advance[0]*(1+self.ring.chro[0]*bunch["delta"]+
- self.ring.adts[0](bunch['x'])+self.ring.adts[2](bunch['y']))
+ self.adts_poly[0](bunch['x'])+self.adts_poly[2](bunch['y']))
phase_advance_y = self.phase_advance[1]*(1+self.ring.chro[1]*bunch["delta"]+
- self.ring.adts[1](bunch['x'])+self.ring.adts[3](bunch['y']))
+ self.adts_poly[1](bunch['x'])+self.adts_poly[3](bunch['y']))
else:
phase_advance_x = self.phase_advance[0]*(1+self.ring.chro[0]*bunch["delta"])
diff --git a/tracking/synchrotron.py b/tracking/synchrotron.py
index 093b274..34cca93 100644
--- a/tracking/synchrotron.py
+++ b/tracking/synchrotron.py
@@ -44,6 +44,19 @@ class Synchrotron:
Horizontal and vertical (non-normalized) chromaticities.
U0 : float, optional
Energy loss per turn in [eV].
+ adts : array of shape (4,) or None, optional
+ Array that contains arrays of polynomial's coefficients, in decreasing
+ powers, used to determine Amplitude-Dependent Tune Shifts (ADTS).
+ The order of the elements strictly needs to be
+ [coef_xx, coef_yx, coef_xy, coef_yy], where x and y denote the horizontal
+ and the vertical plane, respectively, and coef_PQ means the polynomial's
+ coefficients of the ADTS in plane P due to the offset in plane Q.
+
+ For example, if the tune shift in y due to the offset x is characterized
+ by the equation dQy(x) = 3*x**2 + 2*x + 1, then coef_yx takes the form
+ np.array([3, 2, 1]).
+
+ Use None, to exclude the ADTS calculation.
Attributes
----------
--
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