Creation and diagnosis of a solid-density plasma with an X-ray free-electron laser. - Vinko, S. M.; Ciricosta, O.; Cho, B. I.; Engelhorn, K.; Chung, H.-K.; Brown, C. R. D.; Burian, T.; Chalupský, J.; Falcone, R. W.; Graves, C.; Hájková, V.; Higginbotham, A.; et al. (Nature, 2012)