I improvised, departing from a similar body in at least some North American research entities – academic and non. There's no use googling around in this case, becaure the whole thing is kind of lose. But trust me, I don't think the Academic Senate has anything to do with it. Now, you can have an Uchenyj Sovet from the department level – on up. Institute, Faculty, University, Academy, Pearly Gates....Academic Senate, at least in the anglophone context, is more of an ADMINISTRATIVE body treating academic matters rather than actually a SCIENTIFIC body. That's at least my experience of dealing with the academic senates of several north american university in the quality of a professor. Academic senate may alocate research funds but not turn itself into a research seminar. It confers degrees ideed, but does not lend itself to being a scene of thesis defence. Put something vaguer (as I did) – to be on the safe side, for there's no complete semantic equivalent in English... at least not in this context. Ooofff, what a tirade!