This proposal is part of our research programme to explore novel phases in correlated electron systems with strong spin-orbit interaction. Here we aim to probe the spin dynamics in the layered honeycomb magnet alpha-RuCl3. The crystal structure is very close to ideal conditions (near cubic crystal field at Ru sites and near 90 deg Ru-Cl-Ru bonds) proposed theoretically to realize a canonical quantum frustrated system, the Kitaev model on the honeycomb lattice. Here all nearest neighbour bonds are of Ising character, but the three bonds that meet at each site have orthogonal Ising directions, leading to strong frustration effects. This proposal builds upon our successful study using neutron diffraction and inelastic scattering, and resonant x-ray diffraction of the magnetism in the honeycomb iridates (Na/Li)2IrO3 and Li2IrO3 polytypes with three-dimensional honeycomb structures.