diff --git a/smi_analysis/Detector.py b/smi_analysis/Detector.py
index bc13c15..2c04d5b 100644
--- a/smi_analysis/Detector.py
+++ b/smi_analysis/Detector.py
@@ -1,6 +1,6 @@
 import numpy as np
 from pyFAI import detectors
-from pyFAI.detectors import Pilatus, Pilatus300kw, Pilatus1M, Pilatus100k, Pilatus300k, Eiger1M
+from pyFAI.detectors import Pilatus, Pilatus300kw, Pilatus1M, Pilatus100k, Pilatus300k, Eiger1M, Eiger500k
 from pyFAI.detectors._common import Detector
 
 
@@ -289,3 +289,24 @@ def calc_mask(self, img):
                                                 :] = False, False, False, False
 
         return np.logical_not(mask)
+    
+class Eiger500k_xeuss(Eiger500k):
+    '''
+    Eiger1M class inherited from the pyFAI Eiger1M class
+    This class is used to add a specific masking for the Eiger1M of the xeuss instru at CEA
+    '''
+    aliases = ["Eiger1M_xeuss"]
+
+    def calc_mask(self, img):
+        '''
+        :return: (a 2D array) A mask array with 0 and 1 with 0s where the image will be masked
+        '''
+        
+        mask = np.logical_not(np.zeros(np.shape(img)))
+        self.shape= np.shape(img)
+        mask[np.where(img<-0.5)]=False
+
+        mask[:, :5], mask[:, -5:], mask[:5, :], mask[-5:,
+                                                :] = False, False, False, False
+
+        return np.logical_not(mask)
diff --git a/smi_analysis/SMI_beamline.py b/smi_analysis/SMI_beamline.py
index 229ccc1..ca598ef 100644
--- a/smi_analysis/SMI_beamline.py
+++ b/smi_analysis/SMI_beamline.py
@@ -72,8 +72,10 @@ def define_detector(self):
             self.det = Detector.Pilatus300k_OPLS()
         elif self.detector == 'Eiger1M_xeuss':
             self.det = Detector.Eiger1M_xeuss()
+        elif self.detector == 'Eiger500k_xeuss':
+            self.det = Detector.Eiger500k_xeuss()
         else:
-            raise Exception('Unknown detector for SMI. Should be either: Pilatus1m or Pilatus900kw or Pilatus300kw or rayonix')
+            raise Exception('Unknown detector for SMI. Should be either: Pilatus1m or Pilatus900kw or Pilatus300kw or rayonix or Eiger1M_xeuss or Eiger500k_xeuss')
 
     def open_data(self, path, lst_img, optional_mask=None):
         """
@@ -92,7 +94,7 @@ def open_data(self, path, lst_img, optional_mask=None):
             self.bs = self.bs + [[0, 0]]*(len(lst_img) - len(self.bs))
 
         for i, (img, bs) in enumerate(zip(lst_img, self.bs)):
-            if self.detector != 'rayonix' and self.detector != 'Eiger1M_xeuss':
+            if self.detector != 'rayonix' and self.detector != 'Eiger1M_xeuss' and self.detector != 'Eiger500k_xeuss':
                 if self.detector == 'Pilatus900kw':
                     masks = self.det.calc_mask(bs=bs, bs_kind=self.bs_kind, optional_mask=optional_mask)
                     self.masks.append(masks[:, :195])
@@ -139,7 +141,7 @@ def open_data_db(self, lst_img, optional_mask=None):
 
         self.imgs = []
         for img, bs in zip(lst_img, self.bs):
-            if self.detector != 'rayonix' and self.detector != 'Eiger1M_xeuss':
+            if self.detector != 'rayonix' and self.detector != 'Eiger1M_xeuss' and self.detector != 'Eiger500k_xeuss':
                 self.masks.append(self.det.calc_mask(bs=bs, bs_kind=self.bs_kind, optional_mask=optional_mask))
             if self.detector == 'Pilatus1m':
                 self.imgs.append(img)
@@ -166,7 +168,7 @@ def calculate_integrator_trans(self, det_rots):
                                                      )
         ai.set_wavelength(self.wav)
 
-        if self.detector == 'Eiger1M_xeuss':
+        if self.detector == 'Eiger1M_xeuss' or self.detector == 'Eiger500k_xeuss':
             if len(det_rots) == len(self.center) and len(det_rots) == len(self.sdd):
                 for i, (det_rot, center, sdd) in enumerate(zip(det_rots, self.center, self.sdd)):
                     ai.setFit2D(sdd, center[0], center[1])
@@ -193,7 +195,7 @@ def calculate_integrator_trans(self, det_rots):
     def calculate_integrator_gi(self, det_rots):
         ai = Transform(wavelength=self.wav, detector=self.det, incident_angle=self.alphai)
 
-        if self.detector == 'Eiger1M_xeuss':
+        if self.detector == 'Eiger1M_xeuss' or self.detector == 'Eiger500k_xeuss':
             if len(det_rots) == len(self.center) and len(det_rots) == len(self.sdd):
                 for i, (det_rot, center, sdd) in enumerate(zip(det_rots, self.center, self.sdd)):
                     ai.setFit2D(directDist=sdd, centerX=center[0], centerY=center[1])