  We study the reconstruction of the attenuation and absorption coefficients in
a stationary linear transport equation from knowledge of albedo operator in
dimension $n\geq 3$ on a Riemannian manifold in the presence of a magnetic
field. We show the direct boundary value problem is well posed under two types
of subcritical conditions. We obtain uniqueness and non-uniqueness results of
the reconstruction under some restrictions. Finally, stability estimates are
also established.
