Is this river bet worth making?

[nath]

I like it.
A mid pair has every reason to think that you spiked your AK if that's what you were playing.
Only time it doesn't work is if he had a flush draw and caught the king on the end. (Or sometimes the jack, if he wants to call with second pair.)

I tend to think it's a middle pair, rather than some hand like KdQd, but with no reads it's impossible to say. Overall I like the play.