Installation B Task Force: D. Charalambidis, S. Tzortzakis, A. Eglezis

Installation B provides access to high intensity and short pulse duration laser sources. In this respect the following main laser systems are available:

• High intensity laser system operating at 248nm with pulse durations of 150fs, 0.5psec and 5psec. The system is based on the KrF amplification of the doubled output of a subpsec dye laser system at 10Hz providing 10mJ of energy. Focused intensities up to 1016W/cm2 and pulse to background contrast ratio 1010 at the focus can be attained. The subpsec DFDL output at 496nm provides 150m J per pulse at 10Hz rep rate.
• Two amplified Ti:Sapphire fs laser systems at 1kHz, ~1mJ per pulse, at 800nm center wavelength, sub 100fs pulse duration, with doubling and continuum generation options.
• OPG parameteric oscillator covering the visible and infrared ranges.

Installation B focuses mainly in laser matter interactions resulting from intense fields and time resolved phenomena in the gas and condensed phase. Workstations can be configured from dedicated instrumentation such as

• z-scan station: sample scanning along the focus of the laser beam in the open/closed aperture configuration
  pump-probe correlation stations: fs resolution pump probe interferometers in the optical homodyned/heterodyned or imaging configuration, with one or two colour capability.
• VUV-XUV generation station: static cell or pulsed atomic/molecular beam chamber in tandem with differentially pumped spectrometers, in the 30nm-300nm range.
• four-grid reflectron mass spectrometer: UHV station with ionization chamber, Time-of-flight (TOF) tube, sample manipulation, ion erosion gun and dosing sample valve. The small entrance aperture of the TOF and a four-grid reflectron allows quantitative measurements through total ionization saturation. (in collaboration with the Max Planck Institute, Garching)
• photoelectron spectrometer: 20cm magnetically shielded UHV photoelectron spectrometer for gas samples equipped with an electric quadrupole partial pressure detector, with energy resolution (D E/E) ~ 0.06 at 1eV in 3*10-2 srd.
• short duration XUV and x-ray generator: efficient up to 10keV from short laser pulses and e--beams, equipped with a 7-pinhole camera, x-ray spectrometer
• ultrashort high current e--beam sources from photocathodes: fsec laser produced highly directional high current density e- beams from metallic and semiconductor surfaces, with e--current measuring autocorrelator diagnostics

Workstations offer manipulation and handling for multiple laser beams and are fitted with computer based data acquisition systems in configurations for research in

• high-order harmonic generation in gases, plasmas and surfaces: Higher-Order Harmonic Generation and utilization as coherent sources from the VUV and shorter wavelengths.
• multiphoton ionisation cross-sections: Above Threshold Ionization (ATI) studies; Ionization-, autoionization- branching ratios. Quantitative elemental analysis of solid and gaseous samples; Depth profiling; Studies of multiple ionization; Measurement of multiphoton ionization cross sections.
• ultrashort relaxation phenomena in condensed phases and surfaces: relaxation studies of non-linear effects on metallic surfaces and condensed media, direct measurement of energy relaxation times, subpsec time domain reflectometry, Time resolved imaging of ablation, ionization, shock waves. Wave packet dynamics. Propagation of ultrafast NIR pulses in biological materials; Medical optical tomography.
• nonlinear optical properties of materials: measurement of nonlinear optical properties of new materials, optical switches
• high current electron beams: single- and multi-photon non-linear responses of metallic an metallic-implanted surfaces with high efficiency (10-4A/W), directionality of outcoming e--beam (few degrees); polarized e- source from ferromagnetic photocathodes