Geant4 calculations for space radiation shielding material Al2O3 Veli Capali, Tolga Acar Yesil, Gokhan Kaya, Abdullah Kaplan, Mustafa Yavuz and Tahir Tilki EPJ Web of Conferences, 100 (2015) 02002 Published online: 09 July 2015 DOI: 10.1051/epjconf/201510002002