Angle-resolved intensity and energy distributions of positive and negative hydrogen ions released from tungsten surface by molecular hydrogen ion impact

Hydrogen ion reflection properties have been investigated following the injection of H+, H2+ and H3+ ions onto a polycrystalline W surface. Angle- and energy-resolved intensity distributions of both scattered H+ and H− ions are measured by a magnetic momentum analyzer. We have detected atomic hydrogen ions reflected from the surface, while molecular hydrogen ions are unobserved within our detection limit. The reflected hydrogen ion energy is approximately less than one-third of the incident beam energy for H3+ ion injection and less than a half of that for H2+ ion injection. Other reflection properties are very similar to those of monoatomic H+ ion injection. Experimental results are compared to the classical trajectory simulations using the ACAT code based on the binary collision approximation.