TY  - JOUR
A1  - Gorobtsov, Oleg Yu.
A1  - Lorenz, Ulf
A1  - Kabachnik, Nicolai M.
A1  - Vartanyants, Ivan A.
T1  - Theoretical study of electronic damage in single-particle imaging experiments at x-ray free-electron lasers for pulse durations from 0.1 to 10 fs
JF  - Physical review : E, Statistical, nonlinear and soft matter physics
N2  - X-ray free-electron lasers (XFELs) may allow us to employ the single-particle imaging (SPI) method to determine the structure of macromolecules that do not form stable crystals. Ultrashort pulses of 10 fs and less allow us to outrun complete disintegration by Coulomb explosion and minimize radiation damage due to nuclear motion, but electronic damage is still present. The major contribution to the electronic damage comes from the plasma generated in the sample that is strongly dependent on the amount of Auger ionization. Since the Auger process has a characteristic time scale on the order of femtoseconds, one may expect that its contribution will be significantly reduced for attosecond pulses. Here we study the effect of electronic damage on the SPI at pulse durations from 0.1 to 10 fs and in a large range of XFEL fluences to determine optimal conditions for imaging of biological samples. We analyzed the contribution of different electronic excitation processes and found that at fluences higher than 1013-1015 photons/mu m(2) (depending on the photon energy and pulse duration) the diffracted signal saturates and does not increase further. A significant gain in the signal is obtained by reducing the pulse duration from 10 to 1 fs. Pulses below a duration of 1 fs do not give a significant gain in the scattering signal in comparison with 1-fs pulses. We also study the limits imposed on SPI by Compton scattering.
Y1  - 2015
U6  - https://doi.org/10.1103/PhysRevE.91.062712
SN  - 1539-3755
SN  - 1550-2376
VL  - 91
IS  - 6
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Sulyanova, Elena A.
A1  - Shabalin, Anatoly
A1  - Zozulya, Alexey V.
A1  - Meijer, Janne-Mieke
A1  - Dzhigaev, Dmitry
A1  - Gorobtsov, Oleg
A1  - Kurta, Ruslan P.
A1  - Lazarev, Sergey
A1  - Lorenz, Ulf
A1  - Singer, Andrej
A1  - Yefanov, Oleksandr
A1  - Zaluzhnyy, Ivan
A1  - Besedin, Ilya
A1  - Sprung, Michael
A1  - Petukhov, Andrei V.
A1  - Vartanyants, Ivan A.
T1  - Structural Evolution of Colloidal Crystal Films in the Process of Melting Revealed by Bragg Peak Analysis
JF  - Langmuir
N2  - In situ X-ray diffraction studies of structural evolution of colloidal crystal films formed by polystyrene spherical particles upon incremental heating are reported. The Bragg peak parameters, such as peak position, integrated intensity, and radial and azimuthal widths were analyzed as a function of temperature. A quantitative study of colloidal crystal lattice distortions and mosaic spread as a function of temperature was carried out using Williamson-Hall plots based on mosaic block model. The temperature dependence of the diameter of polystyrene particles was obtained from the analysis of Bragg peaks, and the form factor contribution extracted from the diffraction patterns. Four stages of structural evolution in a colloidal crystal upon heating were identified. Based on this analysis, a model of the heating and melting process in the colloidal crystal film is suggested.
Y1  - 2015
U6  - https://doi.org/10.1021/la504652z
SN  - 0743-7463
VL  - 31
IS  - 19
SP  - 5274
EP  - 5283
PB  - American Chemical Society
CY  - Washington
ER  -