OffspecInstrumentItem::createCoordSystem just using scan and det

GUI/Model/Device/InstrumentItems.cpp

@@ -543,12 +543,9 @@ void OffspecInstrumentItem::updateToRealData(const RealItem* dataItem)
 
 const ICoordSystem* OffspecInstrumentItem::createCoordSystem() const
 {
-    IAxis* alphaAxis =
-        new FixedBinAxis("alpha", m_alphaAxis.nbins(), m_alphaAxis.min() * Units::deg,
-                         m_alphaAxis.max() * Units::deg);
-
-    auto d = detectorItem()->createOffspecDetector();
-    return new OffspecCoords(std::vector<const IAxis*>{alphaAxis, d->axis(1).clone()});
+    return new OffspecCoords(
+        std::vector<const IAxis*>{createScan()->coordinateAxis()->clone(),
+                                  detectorItem()->createOffspecDetector()->axis(1).clone()});
 }
 
 ISimulation* OffspecInstrumentItem::createSimulation(const MultiLayer& sample) const