<p>Molecular ion beam enhancement by mixing noble gas at a medium current ion implanter using thermionic hot cathode ion source was confirmed. In this study, 2-methylpentane gas was supplied to ion source as a material gas, and additionally neon or argon gas was supplied as a mixing gas. A IHC (Indirectly Heated Cathode) type ion source was used. Enhancements of both of mixing noble gases molecular ion beam current were confirmed. The enhancement factors were about 170% for CH₃⁺ beam and 180% for C₂H₂⁺ beam mixing neon gas. In case of argon gas mixing, the enhancement factor was about 150% for CH₃⁺ beam.</p> Graphical abstract <p></p>