Assessing the debris generated by the small carry-on impactor operated from the Hayabusa2 mission

We have analyzed the carbonaceous materials generated by the explosion of an High-melting explosive mixture in an Ar atmosphere in a laboratory simulation of the small carry-on impactor experiment. We used both non-destructive and destructive analytical techniques to identify the chemical nature of the materials. From SEM-EDS, we found the materials to be composed mainly of carbon, nitrogen, and oxygen, with a detectable amount of metals. Suitable parameters for identifying these materials are a FTIR peak at 1520 cm^-1, low reflectance and gentle red slope of FTIR spectrum compared with the Murchison CM2 chondrite, the Raman D and G bands, and the hydrogen, carbon, and nitrogen isotopic compositions and their spatial distributions. The scanning transmission X-ray microscopy (STXM)-XANES results provided information about the molecular nature of these highly aromatic materials, which was supported by results from TD-GC/MS. These results suggest that it is possible to distinguish Ryugu samples from SCI potential contaminants in a sample container by using proper combinations of analytical techniques. This assessment provides information that will be useful for the analysis of the Ryugu asteroidal samples. (author)