added undulator

undulator.py

@@ -0,0 +1,189 @@
+from time import sleep
+import numpy as np
+from epics import PV
+
+from slic.core.adjustable import Adjustable
+from slic.core.adjustable import PVAdjustable
+from slic.core.scanner.scanbackend import wait_for_all #, stop_all
+
+
+# 14 is the CHIC
+n_unds = [
+    6, 7, 8, 9, 10, 11, 12, 13,
+    15, 16, 17, 18, 19, 20, 21, 22
+]
+
+und_names = [f"SATUN{n:02}-UIND030" for n in n_unds]
+und_name_cal = "SATUN13-UIND030"
+
+
+
+class Undulators(Adjustable):
+
+    def __init__(self, scaled=True, name="Athos Undulators", units="eV"):
+        super().__init__(name=name, units=units)
+        self.adjs = {name: Undulator(name) for name in und_names}
+        self.chic = CHIC(name, units)
+
+        self.scaled = scaled
+
+        self.convert = ConverterEK()
+
+        a = self.adjs[und_name_cal]
+        self.scale = ScalerEK(a)
+
+
+    def set_target_value(self, value, hold=False):
+        k = self.convert.K(value)
+        if np.isnan(k):
+            print("K is nan for", value)
+            return
+        print(f"{k} <- {value}")
+
+        ks_current = [a.get_current_value(readback=False) for a in self.adjs.values()]
+
+        if self.scaled:
+            header = "scaled:   "
+            ks_target = self.scale.K(value, ks_current)
+        else:
+            header = "all equal:"
+            ks_target = k * np.ones_like(ks_current)
+
+        print(header, ks_target)
+        print()
+
+        def change():
+            #TODO: replace by set_all_target_values_and_wait when print not needed anymore
+            tasks = []
+            for (name, a), k_old, k_new in zip(self.adjs.items(), ks_current, ks_target):
+                delta = k_old - k_new
+                print(f"{name}: {k_old}\t->\t{k_new}\t({delta})")
+                if np.isnan(k_new):
+                    print(f"{name} skipped since target K is nan")
+                    continue
+                t = a.set_target_value(k_new, hold=False)
+                tasks.append(t)
+            wait_for_all(tasks)
+            print("CHIC adjustment follows")
+            self.chic.set_target_value(value, hold=False).wait() #TODO: test whether an additional sleep is needed
+            print("CHIC adjustment done")
+
+        return self._as_task(change, hold=hold)
+
+
+    def get_current_value(self):
+        a = self.adjs[und_name_cal]
+        k = a.get_current_value()
+        energy = self.convert.E(k)
+
+        all_ks = [a.get_current_value() for a in self.adjs.values()]
+        checks = np.isclose(all_ks, k, rtol=0, atol=0.001)
+#        if not all(checks):
+#            print(f"Warning: Ks are not all close to {k}:")
+#            for name, k, chk in zip(self.adjs.keys(), all_ks, checks):
+#                if not chk:
+#                    print(name, k)
+
+        return energy
+
+
+    def is_moving(self):
+        return any(a.is_moving() for a in self.adjs)
+
+
+
+class Undulator(PVAdjustable):
+
+    def __init__(self, name, accuracy=0.0005):
+        pvname_setvalue = name + ":K_SET"
+        pvname_readback = name + ":K_READ"
+        super().__init__(pvname_setvalue, pvname_readback=pvname_readback, accuracy=accuracy, active_move=True, name=name)
+        self.adj_energy = PVAdjustable(name + ":FELPHOTENE")
+
+    @property
+    def energy(self):
+        return self.adj_energy.get_current_value() * 1000
+
+
+
+class ConverterEK:
+
+    h = 4.135667696e-15 # eV * s
+    c = 299792458 # m / s
+    lambda_u = 38e-3 # m
+    const = 2 * h * c / lambda_u # eV
+
+    electron_rest_energy = 0.51099895 # MeV
+
+    def __init__(self, pvname_electron_energy="SATCL01-MBND100:P-READ"):
+        self.pv_electron_energy = PV(pvname_electron_energy)
+
+    def K(self, energy):
+        f = self.get_factor()
+        v = f / energy - 1
+        return np.sqrt(2 * v)
+
+    def E(self, k_value):
+        f = self.get_factor()
+        v = 1 + k_value**2 / 2
+        return f / v
+
+    def get_factor(self):
+        return self.const * self.get_gamma_squared()
+
+    def get_gamma_squared(self):
+        electron_energy = self.pv_electron_energy.get()
+        gamma = electron_energy / self.electron_rest_energy
+        return gamma**2
+
+
+
+class ScalerEK:
+
+    def __init__(self, und_reference):
+        self.und = und_reference
+
+    def K(self, energy_target, K_current=None):
+        if K_current is None:
+            K_current = self.und.get_current_value()
+        K_current = np.asarray(K_current)
+        energy_current = self.und.energy
+        energy_ratio = energy_current / energy_target
+        K_target_squared = energy_ratio * (K_current**2 + 2) - 2
+        return np.sqrt(K_target_squared)
+
+
+
+class CHIC(PVAdjustable):
+
+    def __init__(self, name, units):
+        name += " CHIC Energy"
+        super().__init__("SATUN-CHIC:PHOTON-ENERGY", name=name)
+        self.pvs.start  = PV("SATUN-CHIC:APPLY-DELAY-OFFSET-PHASE")
+        self.units = units
+
+
+    def set_target_value(self, value, hold=False):
+        fudge_offset = 0
+        print("CHIC fudge offset is", fudge_offset)
+        value -= fudge_offset
+        value /= 1000
+
+        def change():
+            sleep(1)
+            print("CHIC setvalue")
+            self.pvs.setvalue.put(value, wait=True)
+            print("CHIC start")
+            self.pvs.start.put(1, wait=True)
+            #TODO: test whether an additional sleep is needed
+            sleep(1)
+
+        return self._as_task(change, hold=hold)
+
+
+    def get_current_value(self):
+        return super().get_current_value() * 1000
+
+
+
+