Add normalised emittance

desy-ml · Sep 3, 2023 · 1d709e6 · 1d709e6
1 parent cab991f
commit 1d709e6
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Showing 2 changed files with 10 additions and 0 deletions.
diff --git a/cheetah/particles.py b/cheetah/particles.py
@@ -181,6 +181,10 @@ def emittance_x(self) -> torch.Tensor:
             self.sigma_x**2 * self.sigma_xp**2 - (self.sigma_x * self.sigma_xp) ** 2
         )
 
+    @property
+    def normalized_emittance_x(self) -> torch.Tensor:
+        return self.emittance_x / self.energy  # TODO: Is this correct?
+
     @property
     def beta_x(self) -> torch.Tensor:
         return self.sigma_x**2 / self.emittance_x
@@ -195,6 +199,10 @@ def emittance_y(self) -> torch.Tensor:
             self.sigma_y**2 * self.sigma_yp**2 - (self.sigma_y * self.sigma_yp) ** 2
         )
 
+    @property
+    def normalized_emittance_y(self) -> torch.Tensor:
+        return self.emittance_y / self.energy  # TODO: Is this correct?
+
     @property
     def beta_y(self) -> torch.Tensor:
         return self.sigma_y**2 / self.emittance_y

diff --git a/test/test_compare_ocelot.py b/test/test_compare_ocelot.py
@@ -223,8 +223,10 @@ def test_twiss():
 
     # Compare
     assert np.isclose(particle_beam.emittance_x, ocelot_twiss.emit_x)
+    assert np.isclose(particle_beam.normalized_emittance_x, ocelot_twiss.emit_xn)
     assert np.isclose(particle_beam.beta_x, ocelot_twiss.beta_x)
     assert np.isclose(particle_beam.alpha_x, ocelot_twiss.alpha_x)
     assert np.isclose(particle_beam.emittance_y, ocelot_twiss.emit_y)
+    assert np.isclose(particle_beam.normalized_emittance_y, ocelot_twiss.emit_yn)
     assert np.isclose(particle_beam.beta_y, ocelot_twiss.beta_y)
     assert np.isclose(particle_beam.alpha_y, ocelot_twiss.alpha_y)