Photon beam using phase space files

== <span style="color:#000080"> Introduction </span> ==

This example shows the dose distribution in water along the incident photon beam. The volume of the water cube is divided into slices perpendicular to the incident beam. At each slice the deposited dose and energy is computed. 

The slices are created using class '''G4PVReplica'''. The energy and dose are scored using classes '''G4UserSteppingAction''' and '''G4UserRunAction'''. Photons are generated using phase-space data files. You can find more information about phase-space data [https://www-nds.iaea.org/phsp/phsp.htmlx here]. There is an option to chose among several '''EM''' physics lists.

== <span style="color:#000080"> How to run the tutorial </span> == 

; Connect to the HEP cluster and create folder PhotonPHSPFolder in your area

<pre style="color: #800000; background-color: #dcdcdc">
ssh -X username@plus1.hep.ucl.ac.uk 

username@plus1.hep.ucl.ac.uk's password: type your password here
 
[username@plus1 ~]$ mkdir PhotonPHSPFolder 

[username@plus1 ~]$ cd PhotonPHSPFolder  
</pre>

; Setup your environment

<pre style="color: #800000; background-color: #dcdcdc">
[username@plus1 PhotonPHSPFolder]$ source /unix/pbt/software/dev/bin/pbt-dev.sh  
</pre>

; Copy the code to your working directory and rename it

<pre style="color: #800000; background-color: #dcdcdc">
[username@plus1 PhotonPHSPFolder]$ cp -r /unix/pbt/tutorials/basic/PhotonPHSP .
  
[username@plus1 PhotonPHSPFolder]$ mv PhotonPHS PhotonPHSP_source
</pre>

; Inside /home/username/PhotonPHSPFolder/ create a directory

<pre style="color: #800000; background-color: #dcdcdc">
[username@plus1 PhotonPHSPFolder]$ mkdir PhotonPHSP_build  
</pre>

; To compile the code enter this directory and run cmake and make 

<pre style="color: #800000; background-color: #dcdcdc">
[username@plus1 PhotonPHSPFolder]$ cd PhotonPHSP_build 

[username@plus1 PhotonPHSP_build]$ cmake -DGeant4_DIR=/unix/pbt/software/dev /home/username/PhotonPHSPFolder/PhotonPHSP_source 

[username@plus1 PhotonPHSP_build]$ make  
</pre>

; Run macro gamma.mac 

<pre style="color: #800000; background-color: #dcdcdc">
[username@plus1 PhotonPHSP_build]$ ./photonPHSP gamma.mac
</pre>
 
== <span style="color:#000080"> How to analyze data </span> ==

=== <span style="color:#000080"> Text files </span> ===

=== <span style="color:#000080"> Run with different settings </span> ===

=== <span style="color:#000080"> Visualisation </span> ===

== <span style="color:#000080"> Files </span> ==