To provide future dependable neutron ux monitoring instrumentation for sodium-cooled fast reactors (SFR) of Generation-IV, French Alternative Energies and Atomic Energy Commission (CEA) is investigating the applicability of an innovative technology based on the optical signal produced within any type of ionization chambers such as ssion chambers for instance. A mock-up of that innovative neutron detector was tested on a cold-neutron beamline at the ORPHEE nuclear facility. Experimental results regarding recovery time and detection eciency showed promising possibilities for neutron instrumentation.