Before any data collection commenced, the sample was annealed in vacuum at 1823 K for at least one hour. In the first data set, TOF distributions of scattered products were collected over a surface temperature (Ts) range of 1023 K to 1823 K in 100 K steps. This study of the temperature dependence of the signal was performed with both increasing and decreasing temperatures. For the increasing temperature sweep, Ts was increased from 1123 K to 1823 K, and for the decreasing temperature sweep, Ts was decreased from 1823 K to 1023 K. For each temperature, TOF distributions were collected at fixed incidence and final angles of θi = θf = 45° for four products detected at mass-to-charge ratios of m/z = 16 (O + ), 32 (O2 + ), 28 (CO + ), and 44 (CO2 + ), with accumulation times corresponding to 500, 500, 1000, and 1000 beam pulses, respectively. The total data collection time at each temperature was 25 minutes. In the second data set, TOF distributions were collected at a variety of final angles in the range, θf = 5° -75°, with a fixed incidence angle of θi = 45°, at two surface temperatures, Ts = 1023 K and 1623 K. To account for any possible long-term drifts in the signal collected at various angles, θf was incremented from low to high and then decremented from high to low, and TOF distributions for all four products were collected at each θf. This procedure was repeated for four temperature sweeps (two up and two down) such that four TOF distributions corresponding to a particular m/z and θf were collected, and these four TOF distributions were then added together. The total numbers of beam pulses corresponding to each TOF distribution collected for a given θf at m/z = 16, 32, 28, and 44 were For the experiments with the hyperthermal Ar beam, a pristine FiberForm sample was used to ensure that there would be no effect on the scattering dynamics of Ar from partially oxidized or etched carbon fibers. Again, the sample was annealed at 1823 K before data were collected.