From bc81dcce00bf9fdcd40a10a959971c7e4820f234 Mon Sep 17 00:00:00 2001
From: Sven <sven.reiche@psi.ch>
Date: Mon, 16 Feb 2026 10:40:26 +0100
Subject: [PATCH] Added radia fit of K-dependent roll-off parameters for Athos
 Apple-X undulators.

---
 model.py | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/model.py b/model.py
index 6e1609f..84e921f 100644
--- a/model.py
+++ b/model.py
@@ -90,14 +90,18 @@ class Model:
         if 'UIND' in name:
             self.om.setRegExpElement(name[0:7], name[8:15], 'K', float(val[0]))
             if 'SATUN' in name:
-                kx = 0
-                ky = 1
-                if 'LV' in val[1]:
-                    kx = 1
-                    ky = 0
-                if 'C' in val[1]:
+                if 'LV' in val[1] or 'LH' in val[1]:
+                    K = float(val[0])
+                    fit = 0.04701805*K*K+ 0.20133565*K+ 0.83336356
+                    if 'LH' in val[1]:
+                        kx = fit
+                        ky = 1 - kx
+                    else:
+                        ky = fit
+                        kx = 1- ky
+                else:
                     kx = 0.5
-                    ky=0.5
+                    ky = 0.5
                 self.om.setRegExpElement(name[0:7], name[8:15], 'kx', kx)
                 self.om.setRegExpElement(name[0:7], name[8:15], 'ky', ky)
         if 'RSYS' in name:
@@ -105,7 +109,6 @@ class Model:
             phase = float(val[1])
             if 'CB' in name[0:7]:
                 grad = grad/ 4.
-            elif 'XB' in name[0:7] or 'SINSB03' in name or 'SINSB04' in name:
                 grad = grad/2
             L = self.om.getRegExpElement(name[0:7], 'RACC', 'Length')[0]
             self.om.setRegExpElement(name[0:7], 'RACC', 'Gradient', grad/L)