Added correction for defocused beam calculation

debye_bec/bec_widgets/widgets/digital_twin/calculations/calc_varia.py

@@ -264,14 +264,24 @@ def fm_ideal_pitch(
         assert fm_focx is not None, "fm_focx must be provided for Defocused mode"
         assert fm_focy is not None, "fm_focy must be provided for Defocused mode"
         a = 2 * np.tan(sldi_hacc) * bl.fm.center[1]  # Beam width at focusing mirror
+        # logger.info(f"a: {a}")
+        # logger.info(f"sldi_hacc: {sldi_hacc}")
+        # logger.info(f"bl.fm.center[1]: {bl.fm.center[1]}")
+        # logger.info(f"p: {p}")
+        # logger.info(f"q: {q}")
         b = (
             2 * np.tan(sldi_vacc) * bl.cm.center[1]
         )  # Beam height at focusing mirror (collimated beam)
         x = fm_focx
+        # logger.info(f"x: {x}")
+        x = 0.098821 * x**2 + 0.512344 * x  # polynom to correct for spot size
+        # logger.info(f"x (corrected): {x}")
         y = fm_focy
         qx = q + x * p / a
-        qy = q + y * p / b
+        qy = q + y * q / b
         f = (p * qx) / (p + qx)  # focal length
+        # logger.info(f"qx: {qx}")
+        # logger.info(f"f: {f}")
     else:  # Calculate for focused beam on sample in "manual" and "focused" mode
         qy = None
         f = (p * q) / (p + q)  # focal length
@@ -280,6 +290,7 @@ def fm_ideal_pitch(
         pitch = np.arcsin(bl.fm.r[0] / (2 * f))  # ideal pitch for FM
     if "Pt" in fm_stripe:
         pitch = np.arcsin(bl.fm.r[1] / (2 * f))  # ideal pitch for FM
+    # logger.info(f"pitch: {pitch}")
     return pitch, qy