I haven't done anything like this, but you can use e.g. wizards for this, wizards are well documented in HELP. e.g. you can call a wizard when user close the ticket, or something like this, or add a tab(survey) to the interaction form and set the fields to mandatory... Or if you're using email services, you can send a mail with the survey automaticaly and the users can reply to it and it would be added to the interaction as an update.
There are many ways as I see, do you have an exact specification how do you want to do this?
I already have one workflow for which I am using the email workflow, but I would like to have a feedback from the user on the email and would like to have it updated on the interaction, can we do that?
could you show the exact steps of the process that you want to implement.
user create ticket in ess->techs solve it and close it--> then user receives a closing notification that containes the survey--> user hit reply on it and send back his answers-->this should create a new activity on the closed interaction?