it is possible to use the ASA with IPS-Module as sensor only, located with her outside-interface on one mirrored switch-port?
The outside-interface is for command and control only and can not be used for monitoring.
The SSM is only able to monitor traffic passing through the ASA.
The ASA does not support connecting it's ports to mirrored switch ports either.
The closest you get is to configure the ASA is transparent mode with ACLs on each interface that permit all traffic, and then place the ASA between 2 of your existing devices. And then place a policy on the ASA to copy all packets to the SSM for promiscuous monitoring.
If you have an existing other type of firewall, then you can try placing the transparent ASA between your other firewall and your DMZ switch for example.
All traffic would be passed through the ASA, and be copied to the SSM for promiscuous monitoring.
This mode could best be described as using the ASA as a simulated Tap to send traffic to the SSM.