Electron probe tweaks (#661)

* Do not overwrite Probe unless requested. Fixes #2515
* Use electron Probe in two ED format classes that were missed before

newsfragments/661.bugfix

@@ -0,0 +1 @@
+The beam probe is no longer reset if any geometrical override is provided at import.

newsfragments/661.feature

@@ -0,0 +1 @@
+Set the beam probe to ``electron`` in both ``FormatNXmxED`` and ``FormatSER``.

src/dxtbx/format/FormatNXmxED.py

@@ -9,6 +9,7 @@
 from dxtbx.format.FormatNXmx import FormatNXmx
 from dxtbx.masking import mask_untrusted_circle, mask_untrusted_polygon
 from dxtbx.model import SimplePxMmStrategy
+from dxtbx.model.beam import Probe
 
 
 class FormatNXmxED(FormatNXmx):
@@ -65,6 +66,7 @@ def _beam(self, index=None):
 
         beam = super()._beam()
         beam.set_polarization_fraction(0.5)
+        beam.set_probe(Probe.electron)
 
         return beam
 

src/dxtbx/format/FormatSER.py

@@ -22,6 +22,7 @@
 from dxtbx import IncorrectFormatError
 from dxtbx.format.Format import Format
 from dxtbx.format.FormatMultiImage import FormatMultiImage
+from dxtbx.model.beam import Probe
 
 
 # The read_emi and _parseEntry_emi functions are taken from openNCEM project
@@ -334,6 +335,7 @@ def cal_wavelength(V0):
             wavelength=wavelength,
             polarization=(0, 1, 0),
             polarization_fraction=0.5,
+            probe=Probe.electron,
         )
 
     def _get_raw_data(self, index):

src/dxtbx/model/beam.py

@@ -122,7 +122,8 @@ def from_phil(
             beam.set_flux(params.beam.flux)
         if params.beam.sample_to_source_distance is not None:
             beam.set_sample_to_source_distance(params.beam.sample_to_source_distance)
-        beam.set_probe(Beam.get_probe_from_name(params.beam.probe))
+        if params.beam.probe != "x-ray":
+            beam.set_probe(Beam.get_probe_from_name(params.beam.probe))
 
         return beam