diff --git a/docs/source/release/v3.13.0/reflectometry.rst b/docs/source/release/v3.13.0/reflectometry.rst
index bb6c11637234e88ed043b71486ef95666d1bb596..a07fc4e6c88a476b3faa7ac06693f058c6736e09 100644
--- a/docs/source/release/v3.13.0/reflectometry.rst
+++ b/docs/source/release/v3.13.0/reflectometry.rst
@@ -49,4 +49,8 @@ Bug fixes
 
 * Correct the angle to the value of ``ThetaIn`` property if summing in lambda in ``ReflectometryReductionOne-v2``.
 
+Liquids Reflectometer
+---------------------
+* New REF_L instrument geometry for 2018 run cycle.
+
 :ref:`Release 3.13.0 <v3.13.0>`
diff --git a/instrument/REF_L_Definition.xml b/instrument/REF_L_Definition.xml
new file mode 100644
index 0000000000000000000000000000000000000000..ef301c678abcef6442263e41645418d0f76ca51a
--- /dev/null
+++ b/instrument/REF_L_Definition.xml
@@ -0,0 +1,78 @@
+<instrument xmlns="http://www.mantidproject.org/IDF/1.0" 
+            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+            xsi:schemaLocation="http://www.mantidproject.org/IDF/1.0 http://schema.mantidproject.org/IDF/1.0/IDFSchema.xsd"
+ name="REF_L" valid-from="2018-06-01 00:00:00" 
+					     valid-to="2100-01-31 23:59:59"
+					     last-modified="2018-06-05 00:00:00">
+  <defaults>
+    <length unit="metre"/>
+    <angle unit="degree"/>
+    <reference-frame>
+      <along-beam axis="z"/>
+      <pointing-up axis="y"/>
+      <handedness val="right"/>
+    </reference-frame>
+  </defaults>
+  <!--SOURCE AND SAMPLE POSITION-->
+  <component type="moderator">
+    <location z="-13.63"/>
+  </component>
+  <type is="Source" name="moderator"/>
+  <component type="sample-position">
+    <location x="0.0" y="0.0" z="0.0"/>
+  </component>
+  <type is="SamplePos" name="sample-position"/>
+
+  <!--DETECTOR-->
+  <component type="DetectorArm">
+    <location>
+      <parameter name="r-position">
+        <value val="0"/>
+      </parameter>
+      <parameter name="t-position">
+        <value val="0"/>
+      </parameter>
+      <parameter name="p-position">
+        <value val="0"/>
+      </parameter>
+      <parameter name="rotx">
+        <value val="0"/>
+      </parameter>
+      <parameter name="roty">
+        <value val="0"/>
+      </parameter>
+      <parameter name="rotz">
+        <value val="0"/>
+      </parameter>
+    </location>
+  </component> 
+
+  <type name="DetectorArm">
+    <component type="panel" idstart="0" idfillbyfirst="y">
+      <location name="detector1">
+        <parameter name="z">
+          <value val="1.83"/>
+        </parameter>
+      </location>
+    </component>
+  </type>
+  
+<!-- Rectangular Detector Panel. Position 256 "pixel" along x 
+     and 304 "pixel" along y  (relative to the coordinate system of the bank) -->
+<type name="panel" is="RectangularDetector" type="pixel"
+    xpixels="256" xstart="-0.1064" xstep="+0.0007"
+    ypixels="304" ystart="-0.0896" ystep="+0.0007" >
+</type>
+
+<!-- Pixel for Detectors. Shape defined to be a (0.0007m)^2 square in XY-plane with tickness 0.0001m -->
+<type is="detector" name="pixel">
+  <cuboid id="pixel-shape">
+    <left-front-bottom-point y="-0.0007" x="-0.0007" z="0.0"/>
+    <left-front-top-point y="0.0007" x="-0.0007" z="0.0"/>
+    <left-back-bottom-point y="-0.0007" x="-0.0007" z="-0.0002"/>
+    <right-front-bottom-point y="-0.0007" x="0.0007" z="0.0"/>
+  </cuboid>
+  <algebra val="pixel-shape"/>
+</type>
+ 
+</instrument>
diff --git a/instrument/REF_L_Definition_after_10102014.xml b/instrument/REF_L_Definition_after_10102014.xml
index 42046dd4d09f77be0078232f1358879071329eba..852a80cc4c6ea61128c56c4f41c726a1d1047ce6 100644
--- a/instrument/REF_L_Definition_after_10102014.xml
+++ b/instrument/REF_L_Definition_after_10102014.xml
@@ -1,7 +1,7 @@
 <instrument xmlns="http://www.mantidproject.org/IDF/1.0" 
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://www.mantidproject.org/IDF/1.0 http://schema.mantidproject.org/IDF/1.0/IDFSchema.xsd"
-            name="REF_L" valid-from="2014-10-10 00:00:02" valid-to="2100-01-31 23:59:59">
+            name="REF_L" valid-from="2014-10-10 00:00:02" valid-to="2018-05-31 23:59:59">
   <defaults>
     <length unit="metre"/>
     <angle unit="degree"/>