We would like to measure number density and length of solar charged particle tracks and solar noble gases in large (>100 µm in diameter) Itokawa grains. The number density (fluence dependent) and track length of solar charged particle tracks (kinetic energy dependent) serve to estimate average energy of solar charged particles that make tracks near the surface (<~10 µm from the surface). Based on the average energy and flux of the solar charged particles, we would like to estimate dwell time of the Itokawa grains near the surface of the asteroid Itokawa and reinterpret noble gas stepwise released patterns. We have already developed a unique analytical procedure, which enables us to obtain mineralogical data (SEM and TEM observation) and noble gas isotopic compositions from each Itokawa grain (Noguchi et al., 2014, 2015). The thickness of typical TEM samples (~100 nm thick) is too thin to obtain reliable average length of solar flare tracks because the average length is expected to be much longer than the thickness of the TEM samples. In this study, we will use thick (~1 µm) sections to measure solar flare track lengths, which reflect kinetic energy of solar flare particles. High voltage electron microscope (HVEM) operated at >1MeV is suitable to observe such thick sections because > 1 MeV electrons transmit easily the sections as thick as 1 µm. We have already found the optimum conditions for the observation of solar flare tracks by HVEM based on our investigation of lunar regolith grains. We will measure the relationship between solar flare number density and the depth from the surface of the grains and that between the solar flare track length and the depth from the surface. To obtain these data, large (~15 µm x ~15 µm x ~1 µm) sections that are cut out normal to the surface are requisites for this study.Therefore, we would like to request large (>100 µm in diameter) grains with various surface morphology, which probably reflects the difference in the exposure history.