| The experimental investigation of ablation on graphite irradiated by high-intensity pulsed ion beam (HIPIB) were performed in TEMP-6 HIPIB apparatus with the ion energy of 300 keV, the pulse width of 70-80 ns, the ion current density of 200-350 A/cm2 and the energy density of 1-12 J/cm2 and ETIGO-II apparatus with 1 MeV, 50-60 ns, 1500 A/cm2 and ～90 J/cm2, respectively. The interaction mechanism between HIPIB and graphite is explored through the thermal-mechanical effect produce by HIPIB irradiation. As confirmed by Raman spectra analysis, formation of diamond-like carbon (DLC) strongly depended on HIPIB parameters. The Raman spectra of the graphite irradiated by HIPIB at the ion current density of 200A/cm2 have apparent G peak and D peak at around 1580 cm-1 and 1334 cm-1, respectively, similar to that of original graphite. Notable changes are found for Raman spectra of graphite irradiated at 350 A/cm2. With 1 shot, the spectrum of the irradiated graphite has no obvious changes compared to that of 200A/cm2. Increasing the shot number up to 5 shots, the spectra showed a broadened asymmetric peak between 1100 and 1700 cm-1. It was thus confirmed that diamond-like carbon (DLC) was preferably formed at these conditions. Further increased the ion current density to 1500 A/cm2, a spectrum similar to that of 200A/cm2 was obtained, which indicated that no DLC formed on the irradiated graphite. At 350 A/cm2, the surface presents a trend of densifying with repetitive irradiation up to 5 shots by scanning electron microscope (SEM), correlating to the formation of DLC with a density higher than that of graphite. The ablation process of graphite was modeled by using the established theoretical model of heat transfer during phase transformation in materials irradiated by HIPIB. The calculation showed that the temperature profile in irradiated graphite at 350 A/cm2 is almost identical to that at 200 A/cm2, showing a deeper heat-affected zone in comparison with that of 1500 A/cm2. For instance, the depth heated up to 2000 K is about 4-5 μm for both 200 and 350 A/cm2, and only 2 μm for 1500 A/cm2. Moreover, the ablation depth per shot is around 0.8 )μm at 350 A/cm , higher than that of 0.4 μm at 200 A/cm2 and much...
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