Fig. 7: Comparison of the isotopic composition of Ne in the lunar soil.

The (²⁰Ne/²²Ne)_tr ratios of the CE-5 bulk soil seem less fractionated than those of the Apollo soils, particularly for the (²⁰Ne/²²Ne)_tr ratio in ilmenite, which is very close to that of the modern solar wind, indicating that the secondary process endured by the CE-5 soils was not strong. The relatively higher ²¹Ne/²²Ne ratios of the CE-5 soil than those of other lunar soils indicate that the sample contains a certain proportion of cosmogenic ²¹Ne, which may result from the longer cosmic-ray irradiation time than those of the Apollo samples. The uncertainties of (²⁰Ne/²²Ne)_tr ratios in CE-5 samples are at 1σ. The data of Apollo soils are from previous reports^{16,17,19,22,28,31,53,54,57}.