TY - DATA T1 - Absorption cross-section σ (red, left-hand y-axis), and transmission (right-hand y-axis) for different column densities (/1017 cm−2) PY - 2013/08/13 AU - James R Harries AU - Mitsuru Nagasono AU - Hiroshi Iwayama AU - Eiji Shigemasa UR - https://iop.figshare.com/articles/figure/_Absorption_cross_section_red_left_hand_em_y_em_axis_and_transmission_right_hand_em_y_em_axis_for_di/1012437 DO - 10.6084/m9.figshare.1012437.v1 L4 - https://ndownloader.figshare.com/files/1480259 KW - wavelength KW - scss KW - helium gas cell KW - fel KW - SASE pulses KW - Atomic Physics KW - Molecular Physics N2 - Figure 1. Absorption cross-section σ (red, left-hand y-axis), and transmission (right-hand y-axis) for different column densities (/1017 cm−2). Abstract Using the third harmonic of the FEL radiation from the SPring-8 compact SASE (self-amplified stimulated emission) source SCSS we have studied the effects on SASE pulses with central wavelengths near 20 nm due to passage through a helium gas cell. The positions of zero ionization cross-section close to wavelengths corresponding to double-excitations allow operation as an efficient wavelength filter, with effectively 100% transmitted peak intensity until the Doppler-broadening limit is reached. We discuss how the time profile of the SASE pulses is affected, and discuss potential applications. ER -