't Hoen, M. H. J., Mayer, M., Kleyn, A. W., & Zeijlmans van Emmichoven, P. A. (2013). Strongly Reduced Penetration of Atomic Deuterium in Radiation-Damaged Tungsten. Physical Review Letters, 111: 225001 (5pp). doi:10.1103/PhysRevLett.111.225001.