Inefficient Vibrational Cooling of C₆₀ in a Supersonic Expansion

Figure 2

Plot of calculated 𝑆/𝑁 versus frequency. The 𝑆/𝑁 was calculated at 𝑇_rot=20 K, 𝑇_vib=0 K, 𝐵^′′=0.0028 cm⁻¹, 𝐵^′=0.002795 cm⁻¹, 𝜁=−0.0319, oven temperature of 955 K, and a mass loss of 2.0 g/hr, corresponding to a probed number density of ¹²C₆₀ in the expansion of 1.7×10¹² cm⁻³. The assumed noise level was 1.0 ppm and the linewidth for the transitions was set to 0.0004 cm⁻¹. The largest value of 𝑆/𝑁 for a single rovibrational transition is ~130. These parameters are similar to our experimental parameters for attempt 1 listed in Table 1. The value for 𝜁 comes from [17].