  We study the production of prompt-photons at RHIC in the context of a
generalised parton model framework, with a view to obtain information on the
gluon Sivers function (GSF). At RHIC energy ($\sqrt{s}=200$ GeV), the Compton
process, $gq\to\gamma q$ contributes significantly to the production of
direct-photons at midrapidity and dominates it in the negative (backward)
rapdity region. We find that for direct photons, asymmetries of upto 10\% are
allowed by a maximal gluon Sivers function. However, the asymmetry obtained
using existing fits of the GSF available is literature is negligible. We also
estimate the impact that photons produced via fragmentation can have on the
signal and find that their inclusion can dilute the asymmetry by between
10-50\% of the direct-photon value. Finally, using the Colour-Gauge Invariant
generalised parton model (CGI-GPM) approach, we consider the effects of initial
state and final state interactions which can affect the universality of the
Sivers functions in different processes. We find that the inclusion of these
effects leads to the size of the gluon contributions being roughly halved.
However, in the backward region which we are interested in, the sizes of the
quark contributions are suppressed even further, leading to increased dominance
of the gluon contributions.
