  In relativistic nuclear collisions some of the important aspects to be
addressed are the effects of the nuclear PDF and the gluon saturation. In the
LHC the best way to address these questions is by means of pA collisions and in
particular through the measurement of direct photon production in the forward
direction. In order to achieve this measurement a new forward calorimeter
(FoCal) is proposed as an upgrade to the ALICE experiment. The proposed
detector will cover the range 3.5 < $\eta$ < 5, probing the gluon distributions
at x$\sim$10$^{-5}$ and Q$\sim p_{\rm T}$ > 4 GeV. We will discuss performance
studies and demonstrate that extremely high-granularity calorimetry is required
for such measurement. We will also present a few results from R\&D for this
project.
