Simple feedback class

mbtrack2/tracking/SimpleFeedBack.py

+# -*- coding: utf-8 -*-
+"""
+Created on Wed Jun  8 16:24:19 2022
+
+@author: sauret
+"""
+from mbtrack2.tracking.element import Element
+import numpy as np
+
+class SimpleFB(Element) : 
+    """ 
+   Simple feedback system proceeding bunch by bunch correction to counter beam 
+   instabilities
+   
+   Parameters
+   ----------
+   ring : Synchrotron object
+   damping_time : array of shape (3,), optional
+       Contains the desired damping time in seconds for each plane in the same 
+       order sepcified in plane.
+   phase_diff : float, optional
+       Phase of the damper kick in degrees.
+   plane : bool array of shape (3,), optional
+       Allow to choose on which plane the feedback is active. State True to
+       turn on the feedback or False otherwise. Element 0 of the array defines
+       the longitunal plane as 1 and 2 define the horizontal and vertical plane
+       respectively.
+    """
+    
+    def __init__(self, ring,phase_diff = 90, damping_time = np.array([2e-3,2e-5,2e-5]),plane = np.ones((3,), dtype= bool)):
+        self.ring = ring
+        self.damping_time = damping_time
+        self.phase_diff = phase_diff
+        self.plane = plane 
+        
+    @Element.parallel 
+    def track(self, bunch):
+        """
+        Tracking method for the feedback system
+        No bunch to bunch interaction, so written for Bunch object and
+        @Element.parallel is used to handle Beam object.
+        
+        Parameters
+        ----------
+        bunch : Bunch or Beam object
+        """
+        if(self.plane[0] == True):
+            bunch["delta"] -= (2*self.ring.T0/self.damping_time[0])*np.sin(self.phase_diff)*bunch.mean[5]
+        
+        if(self.plane[1] == True):
+            bunch["xp"] -= (2*self.ring.T0/self.damping_time[1])*np.sin(self.phase_diff)*bunch.mean[1]
+        
+        if(self.plane[2] == True):
+            bunch["yp"] -= (2*self.ring.T0/self.damping_time[2])*np.sin(self.phase_diff)*bunch.mean[3]
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