Abstract: H₂ discharge in RF ion source of neutron tube,was mathematically formulated with 2 D axisymmetric inductively coupled plasma(ICP) model,theoretically analyzed in Maxwell equations and numerically simulated with Comsol software.The influence of the factors,including the pressure,number/spacing of turns,diameter and power of coil,on the H⁺-density was investigated.The simulated results show that the H⁺-density strongly depends on the pressure and coil diameter,but weakly on the power and number/spacing of turns.For example,an increase of coil diameter(discharge pressure) significantly increases the H⁺-density,because of larger ionization cross-section(because of higher density of particles).As the turn's number increases from 1 to 7,the H⁺-density increases at a decreasing rate.The power and turn's pacing little affect the H⁺-density.We suggest that simulated results be of some technological interest in design optimization of RF ion source of neuron tube.