Simplify the following text for a Grade 10 native English-speaking person.
Original: Together they set up a laboratory in the stables where they worked on the ionisation of phosphorus and also on the photo-chemical reaction of carbon monoxide and chlorine .
Simplified: While he was interned , he had the freedom to set up a laboratory in the stables . With the help of Charles Ellis he worked on the ionization of phosphorus and also on the photo-chemical reaction of carbon monoxide and chlorine .