diff --git a/NPSimulation/Detectors/FissionChamber/FissionChamber.cc b/NPSimulation/Detectors/FissionChamber/FissionChamber.cc
index 4b0e80d3dcaea1c5beeba411d66bfac28a4094bd..24ae20e988e0397d6dfd140a6b48b1f25c233ea7 100644
--- a/NPSimulation/Detectors/FissionChamber/FissionChamber.cc
+++ b/NPSimulation/Detectors/FissionChamber/FissionChamber.cc
@@ -173,8 +173,7 @@ void FissionChamber::ConstructDetector(G4LogicalVolume* world){
     G4double wY = m_R[i] * sin(m_Theta[i] ) * sin(m_Phi[i] ) ;
     G4double wZ = m_R[i] * cos(m_Theta[i] ) ;
     G4ThreeVector Det_pos = G4ThreeVector(wX, wY, wZ) ;
-    // So the face of the detector is at R instead of the middle
-    Det_pos+=Det_pos.unit()*FissionChamber_NS::Thickness*0.5;
+    
     // Building Detector reference frame
     G4double ii = cos(m_Theta[i]) * cos(m_Phi[i]);
     G4double jj = cos(m_Theta[i]) * sin(m_Phi[i]);