  We compute the Boundary Superstring Field Theory partition function on the
annulus in the presence of independent linear tachyon profiles on the two
boundaries. The R-R sector is found to contribute non-trivially to the
derivative terms of the space-time effective action. In the process we
construct a boundary state description of D-branes in the presence of a linear
tachyon. We quantize the open string in a tachyonic background and address the
question of open/closed string duality.
