Thank you for a quick response
The tmp directory looks like this
241M ./assets/
904K ./runtime/
8.0K ./upload/
The assets directory contains loads of subdirectories, which looks like a sort of hash key .....
The majority have a timestamp from the install, there are five directories updated today.
All settings are set to default, the only change I have made is to extend the bootstrap theme to use some local CSS for the survey.
In essence, it is "straight out of the box".