Generation, diagnosis and application of femtosecond electron single bunch

A new S-band laser photocathode RF gun and chicane-type magnetic pulse comp ressor were installed in the twin linac system of Nuclear Engineering Resea rch Laboratory, University of Tokyo. Low emittance (6 pi mm. mrad) femtosec ond (240-290 fs at FWHM) electron single bunch of 16 MeV, 2% energy spread and 350pC/bunch was obtained. Femtosecond streak camera (200fs resolution) with dispersionless reflective optics, coherent transition radiation interf erometer and far-infrared polychromator were used. We conclude that the str eak camera and polychromator are the best for longer than 200 fs (FWHM) bun ch and for shorter, respectively. Detailed performances of the RF gun including the linac laser synchronizati on and the reduction of dark currents were precisely evaluated. Further, we tried a new femtosecond quantum beam based pump-and-probe analysis, which is the lime-resolved X-ray diffraction to visualize atomic motions. X-ray d iffraction patterns of CuK alpha(1,2) from several monocrystal such as GaAs , KCl, CaF2 were obtained using 10 ps X-ray pulses. The visualization is un der way. Finally, we introduce the new femtosecond ultrafast quantum phenom ena research facility.