First lasing of the Israeli tandem electrostatic accelerator free electron laser

First lasing at 3 mm wavelength was achieved on December 4, 1996 in our FEL employing a modified EN-Tandem electrostatic accelerator as the source of energetic free electrons. A Pierce-type electron gun capable of providing a 2A beam was installed at the entrance to the accelerator and operated at 1.4 A level, while the wiggler (/spl lambda//sub w/=4.4 cm, N/sub w/=26) was located in the center of the accelerator, inside the positive HV terminal. The electron gun voltage was V/sub gun/=-43 kV and the terminal operating voltage V/sub term/=1.4 MV. The resonator, consisting of a two parallel curved plates waveguide terminated by wave splitters at its both ends, was mounted inside the wiggler. Radiation pulses at 100.5 GHz of 2 /spl mu/sec duration and 1200 W of power were obtained at intervals of 15 sec.