diff --git a/src/docs/part1/simple_detector.md b/src/docs/part1/simple_detector.md
index 1e9454610823686775a9e57fb529886d420ece12..4dcad4c8816ff149692c83670a1f8f59320cbe1a 100644
--- a/src/docs/part1/simple_detector.md
+++ b/src/docs/part1/simple_detector.md
@@ -54,10 +54,22 @@ ddsim  --runType run  --enableG4GPS \
 This will run geant4 using the General Particle Source (GPS) tool.
 The output will be a root file containing the generated events and GEM tracker hits.
 
+See the [GPS Documentation](http://www.fe.infn.it/u/paterno/Geant4_tutorial/slides_further/GPS/GPS.pdf) for more information.
+
+
 ## Digitization 
 
 ```bash
 root -b -q example_digi.cxx+
 ```
-![digi histogram](example_digi.png)
+![digi histogram](../example_digi.png)
+
+## Channel/Cell Size
+
+```bash
+root -b -q example_cell_size.cxx+
+    
+```
+![cell size histogram](../example_cell_size.png)
+
 
diff --git a/static/example_cell_size.png b/static/example_cell_size.png
index a7bf0616a903dceaf566688b88246b533fc9f8a4..2bd35f6f67d328f0140ad15e85d228400346ac66 100644
Binary files a/static/example_cell_size.png and b/static/example_cell_size.png differ