diff --git a/src/pg_rad/physics/__init__.py b/src/pg_rad/physics/__init__.py
new file mode 100644
index 0000000..fe9b62d
--- /dev/null
+++ b/src/pg_rad/physics/__init__.py
@@ -0,0 +1,10 @@
+# do not expose internal logger when running mkinit
+__ignore__ = ["logger"]
+from pg_rad.physics import attenuation
+from pg_rad.physics import fluence
+
+from pg_rad.physics.attenuation import (get_mass_attenuation_coeff,)
+from pg_rad.physics.fluence import (phi_single_source,)
+
+__all__ = ['attenuation', 'fluence', 'get_mass_attenuation_coeff',
+           'phi_single_source']