Something different for a change, missing persons!

Well boys and girls, looks like we have another case or should I say cache for you (can S be pronounced CH?)
The scientist, Dr Alan Jones has not been seen since he left the Jet Laboratories at Culham the day before Christmas Eve, and not as reported elsewhere. We have made an appeal to the public for information but to date we have not received anything.
He is the gentleman on the top row, white coat and right of centre.
Can you help?

Lewis