. . "Falcone, R. W." . "6"^^ . "Brown, C.R.D." . . "109" . "Wu, B." . "Lee, R. W." . "0031-9007" . "RIV/68378271:_____/12:00386076" . "Wark, J. S." . "33"^^ . "[626B2D389A86]" . . "165241" . "Wang, T." . . "We report here on the resonant generation of K \u03B1 emission, that is to say the production of copious K \u03B1 radiation by tuning the x-ray FEL pulse to photon energies below that of the K edge of a solid aluminum sample. The sequential absorption of multiple photons in the same atom during the 80 fs pulse, with photons creating L-shell holes and then one resonantly exciting a K-shell electron into one of these holes, opens up a channel for the K\u03B1 production, as well as the absorption of further photons.We demonstrate rich spectra of such channels, and investigate the emission produced by tuning the FEL energy to the K-L transitions of those highly charged ions that have transition energies below the K edge of the cold material. The spectra are sensitive to x-ray intensity dependent opacity effects, with ions containing L-shell holes readily reabsorbing the K \u03B1 radiation." . "Chung, H.-K." . . . . . . "Nagler, B." . "Resonant K\u03B1 spectroscopy of solid-density aluminum plasmas"@en . "Engelhorn, K." . "Higginbotham, A." . "Ping, Y." . . "RIV/68378271:_____/12:00386076!RIV13-GA0-68378271" . . "Chalupsk\u00FD, Jarom\u00EDr" . . "Krzywinski, J." . "H\u00E1jkov\u00E1, V\u011Bra" . . "Cho, B. I." . "US - Spojen\u00E9 st\u00E1ty americk\u00E9" . "Resonant K\u03B1 spectroscopy of solid-density aluminum plasmas"@en . "Physical Review Letters" . . "K\u03B1 spectroscopy; free-electron lasers; solid-density aluminum plasmas"@en . . "Murphy, C." . . "Resonant K\u03B1 spectroscopy of solid-density aluminum plasmas" . "We report here on the resonant generation of K \u03B1 emission, that is to say the production of copious K \u03B1 radiation by tuning the x-ray FEL pulse to photon energies below that of the K edge of a solid aluminum sample. The sequential absorption of multiple photons in the same atom during the 80 fs pulse, with photons creating L-shell holes and then one resonantly exciting a K-shell electron into one of these holes, opens up a channel for the K\u03B1 production, as well as the absorption of further photons.We demonstrate rich spectra of such channels, and investigate the emission produced by tuning the FEL energy to the K-L transitions of those highly charged ions that have transition energies below the K edge of the cold material. The spectra are sensitive to x-ray intensity dependent opacity effects, with ions containing L-shell holes readily reabsorbing the K \u03B1 radiation."@en . "Juha, Libor" . "Zhu, D." . . . . "Zastrau, U." . "P(ED1.1.00/02.0061), P(EE.2.3.20.0087), P(EE2.3.30.0057), P(GAP108/11/1312), P(GAP205/11/0571), P(GAP208/10/2302), P(LA08024), P(ME10046), Z(AV0Z10100523)" . "Vinko, S. M." . "000312068300021" . "Scherz, A." . "Graves, C." . "Rackstraw, D. S." . . "Ciricosta, O." . . . "Toleikis, S." . "10.1103/PhysRevLett.109.245003" . . "Messersmidt, M." . "Vy\u0161\u00EDn, Lud\u011Bk" . . "Resonant K\u03B1 spectroscopy of solid-density aluminum plasmas" . . "Lee, H. J." . . "24" . "Burian, Tom\u00E1\u0161" . "Heimann, P. A." . . "Turner, J. J." . . "Schlotter, W." . "5"^^ . "Rohringer, N." .