Current status report of subpicosecond electron linac of NERL of Univ. of Tokyo

The new laboratory of Beam-Material Interaction started this April to promote generation and application of ultrashort quantum beams. 8 research subjects have been accepted and performed in the linac facility in this fiscal year. Coherent transition radiation interferometry is applied to picosecond electron bunch measurement. The results agree with the results obtained by the femtosecond streak camera. The experiment of the laser wakefield acceleration is under way under the collaboration with KEK and JAERI-Kansai. The 18L linac of the twin linacs has been modified for femtosecond X-ray pulse generation via Thomson backward scattering. The laser photocathode RF gun and the chicane-type magnetic pulse compressor have been installed. The first experiment has been carried out in August and September. X-ray diffraction of an ionic nomocrystal (NaCl) was performed using subpicosecond X-ray pulse. The low power X-band RF test for the X-band femtosecond linac and the design study of the linac with the laser photocathode S-band RF gun is carried out. (author)