How can we automatically send a survey form to participants after an event?
2 Answers
You can use the CiviRules extension to do that? There is a CiviRules Guide which should help you to understand what it does and how to use it.
It depends what you mean by 'survey form' but you can set a Scheduled Reminder to go out x hours, or y days, after an event.
Then that link can go to eg a Profile or if you are using Drupal, a webform so that the 'survey' gets recorded as an Activity AND you can mark off on the Participant record that they have responded.