TY - JOUR
T1 - Subthreshold erosion of an organic polymer induced by multiple shots of an X-ray free-electron laser
AU - Burian, T.
AU - Chalupský, J.
AU - Hájková, V.
AU - Toufarová, M.
AU - Vorlíček, V.
AU - Hau-Riege, S.
AU - Krzywinski, J.
AU - Bozek, J. D.
AU - Bostedt, C.
AU - Graf, A. T.
AU - Jastrow, U. F.
AU - Kreis, S.
AU - London, R. A.
AU - Messerschmidt, M.
AU - Moeller, S.
AU - Sobierajski, R.
AU - Tiedtke, K.
AU - De Grazia, M.
AU - Auguste, T.
AU - Carré, B.
AU - Guizard, S.
AU - Merdji, H.
AU - Medvedev, N.
AU - Juha, L.
N1 - Publisher Copyright:
© 2020 American Physical Society.
PY - 2020/9
Y1 - 2020/9
N2 - Solids irradiated by energetic photons can be eroded in two modes, depending on the radiation intensity. High average, low-peak power sources, e.g., synchrotron radiation and high-order harmonics, induce desorption of the material at a low etch rate. In contrast, high-peak-power radiation from extreme ultraviolet and X-ray lasers usually causes a massive removal of the material even by a single shot. In this contribution, an effective material erosion is reported in PMMA exposed to multiple accumulated pulses generated by the free-electron X-ray-laser Linac Coherent Light Source (LCLS, tuned at a photon energy of 830 eV in this study, operated in Menlo Park at Stanford, CA, USA) at a fluence below the single-pulse ablation threshold. The effect is caused by polymer-chain scissions initiated by single photons carrying enough energy to break the C-C bounds. High efficiency of the erosion is supposed to occur due to a correlation of the single-photon effects. The subthreshold damage exhibits a nonlinear dose dependence resulting from a competition between chain scissions and cross-linking processes. The cross-linking is proven by Raman spectroscopy of the irradiated polymer. Two theoretical models of the X-ray free-electron-laser-induced erosion are suggested, which provide an excellent agreement with the experimental results.
AB - Solids irradiated by energetic photons can be eroded in two modes, depending on the radiation intensity. High average, low-peak power sources, e.g., synchrotron radiation and high-order harmonics, induce desorption of the material at a low etch rate. In contrast, high-peak-power radiation from extreme ultraviolet and X-ray lasers usually causes a massive removal of the material even by a single shot. In this contribution, an effective material erosion is reported in PMMA exposed to multiple accumulated pulses generated by the free-electron X-ray-laser Linac Coherent Light Source (LCLS, tuned at a photon energy of 830 eV in this study, operated in Menlo Park at Stanford, CA, USA) at a fluence below the single-pulse ablation threshold. The effect is caused by polymer-chain scissions initiated by single photons carrying enough energy to break the C-C bounds. High efficiency of the erosion is supposed to occur due to a correlation of the single-photon effects. The subthreshold damage exhibits a nonlinear dose dependence resulting from a competition between chain scissions and cross-linking processes. The cross-linking is proven by Raman spectroscopy of the irradiated polymer. Two theoretical models of the X-ray free-electron-laser-induced erosion are suggested, which provide an excellent agreement with the experimental results.
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U2 - 10.1103/PhysRevApplied.14.034057
DO - 10.1103/PhysRevApplied.14.034057
M3 - Article
AN - SCOPUS:85093110265
SN - 2331-7019
VL - 14
JO - Physical Review Applied
JF - Physical Review Applied
IS - 3
M1 - 034057
ER -