From ebe345cd3df0f3dbb4fe7d8451399a415ff58317 Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Mon, 20 Jul 2026 09:05:03 -0500
Subject: [PATCH] Change name to displacement_energy, remove test

---
 openmc/data/njoy.py                   | 18 +++++++-----------
 tests/unit_tests/test_data_neutron.py |  8 --------
 2 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/openmc/data/njoy.py b/openmc/data/njoy.py
index 3d0fcc110..7c99637f0 100644
--- a/openmc/data/njoy.py
+++ b/openmc/data/njoy.py
@@ -259,14 +259,14 @@ broadr / %%%%%%%%%%%%%%%%%%%%%%% Doppler broaden XS %%%%%%%%%%%%%%%%%%%%%%%%%%%%
 _TEMPLATE_HEATR = """
 heatr / %%%%%%%%%%%%%%%%%%%%%%%%% Add heating kerma %%%%%%%%%%%%%%%%%%%%%%%%%%%%
 {nendf} {nheatr_in} {nheatr} /
-{mat} 4 0 0 0 0 {damage_threshold}/
+{mat} 4 0 0 0 0 {ed}/
 302 318 402 444 /
 """
 
 _TEMPLATE_HEATR_LOCAL = """
 heatr / %%%%%%%%%%%%%%%%% Add heating kerma (local photons) %%%%%%%%%%%%%%%%%%%%
 {nendf} {nheatr_in} {nheatr_local} /
-{mat} 4 0 0 1 0 {damage_threshold}/
+{mat} 4 0 0 1 0 {ed}/
 302 318 402 444 /
 """
 
@@ -411,7 +411,7 @@ def make_pendf(filename, pendf='pendf', **kwargs):
 def make_ace(filename, temperatures=None, acer=True, xsdir=None,
              output_dir=None, pendf=False, error=0.001, broadr=True,
              heatr=True, gaspr=True, purr=True, evaluation=None,
-             smoothing=True, damage_threshold=None, **kwargs):
+             smoothing=True, displacement_energy=None, **kwargs):
     """Generate incident neutron ACE file from an ENDF file
 
     File names can be passed to
@@ -463,8 +463,9 @@ def make_ace(filename, temperatures=None, acer=True, xsdir=None,
         indicates which evaluation should be used.
     smoothing : bool, optional
         If the smoothing option (ACER card 6) is on (True) or off (False).
-    damage_threshold : float, optional
-        Displacement damage threshold in eV. Used in heatr to calculate damage-energy cross section. When None use NJOY defaults.
+    displacement_energy : float, optional
+        Threshold displacement energy in [eV]. Used in HEATR to calculate
+        damage-energy cross section. When None, use NJOY defaults.
     **kwargs
         Keyword arguments passed to :func:`openmc.data.njoy.run`
 
@@ -517,12 +518,7 @@ def make_ace(filename, temperatures=None, acer=True, xsdir=None,
 
     # heatr
     if heatr:
-        # prevent using NJOY default by setting to a small number
-        if damage_threshold == 0.0:
-            damage_threshold = 1e-5
-        # the NJOY default is 0
-        if damage_threshold is None:
-            damage_threshold = 0.0
+        ed = displacement_energy if displacement_energy is not None else 0
         nheatr_in = nlast
         nheatr_local = nheatr_in + 1
         tapeout[nheatr_local] = (output_dir / "heatr_local") if heatr is True \
diff --git a/tests/unit_tests/test_data_neutron.py b/tests/unit_tests/test_data_neutron.py
index 115541a06..c767f0171 100644
--- a/tests/unit_tests/test_data_neutron.py
+++ b/tests/unit_tests/test_data_neutron.py
@@ -244,14 +244,6 @@ def test_kerma(run_in_tmpdir, am244, h2):
     assert 901 in read_in
     assert np.all(read_in[901].xs['300K'].y == h2[901].xs['300K'].y)
 
-@needs_njoy
-def test_damage_energy(tmpdir, endf_data):
-    endf_file = os.path.join(endf_data, 'neutrons', 'n-014_Si_030.endf')
-    si30 = openmc.data.IncidentNeutron.from_njoy(endf_file)
-
-    si30_copy = openmc.data.IncidentNeutron.from_njoy(endf_file, damage_threshold=100)
-    assert not np.allclose(si30[444].xs['294K'].y, si30_copy[444].xs['294K'](si30[444].xs['294K'].x))
-                            
 
 def test_urr(pu239):
     for T, ptable in pu239.urr.items():