SND@LHC upgrades

SND@LHC is a forward experiment measuring neutrinos produced at the LHC, operating since the beginning of Run 3 in 2022. The first physics data yielded, among the rest, the first observation of neutrinos produced at a collider. The detector currently in use is a hybrid system based on a 830 kg nuclear emulsions and tungsten target, with interleaved scintillating fiber tracker planes, followed by a hadronic calorimeter and a muon system. Its configuration allows to identify all three neutrino flavours, opening a unique opportunity to probe heavy flavour production in a $\eta$ region not accessible to ATLAS, CMS and LHCb. A thorough upgrade is foreseen for LHC Run 4: in the new detector emulsions will be replaced with silicon sensors and a magnetised hadronic calorimeter will be used. The sensitive material of both systems will consist of silicon strips from the current CMS tracker, which will be decommissioned at the end of Run 3. The upgraded detector will lead to a significant reduction of statistical and systematic uncertainties and will allow to measure the $\nu_\mu N$ interaction cross section.