What is this scale?

So the scale goes like this: F, F#, A, A#, C#, D, E. I'm not sure the root is F tho, could be F#, the piece uses F# minor chord heavily.

When written enharmonically with D as the root we get the notes: D, E, F, Gb, A, Bb, C#.

Thus, we can see we almost have the scale of D harmonic minor but with a G flat.

In essence it is just a synthetic scale based upon the harmonic minor scale of D, with a flattened fourth degree.

I was thinking the same thing, but in the entire piece Dmin chord appears only once or twice, isn't it unusual that the root chord isnt used? Also there is a lot of movement based around F# as sort of a pivot note.

can be many reasons for that.. suspended tonality perhaps? Or maybe the tonal center is not the D of the scale, but F like you originally suggested? The latter would then be of course similar to the use of modes, by that i mean all modes have a diatonic key signature but begin and revolve around different degrees of the scale.