Estimates of magnetospheric solar wind charge exchange events detectable with GEO-X

We present estimates of magnetospheric solar wind charge exchange soft X-ray events detectable with GEO-X. The OVII X-ray line flux was calculated using the latest calibrated ACE/SWICS data on solar wind O7+ ions and scaled to the sum of emission lines from other solar wind ions, based on past Suzaku magnetospheric charge exchange events. The instrumental background, including radiation noise mainly due to energetic protons, was estimated using GOES proton flux and our previously developed GEANT4 simulation. The number of detectable events meeting a criterion of S/N > 20 peaks around the solar maximum, reaching 43.7 events per year with an average duration of 6.96 hours. Assuming an observation efficiency of 30%, we found that at least one event can be detected within a 4-month timeframe with a 90% probability.