Author/Authors :
Saeki، نويسنده , , K. and Okuma، نويسنده , , S. and Oshita، نويسنده , , E. and Wakita، نويسنده , , K. and Kobayashi، نويسنده , , A. and Tomimasu، نويسنده , , T.، نويسنده ,
Abstract :
The g-parameters of two optical cavities whose length is 6.718 m are designed to be stable. The FEL beam is outcoupled from the upstream mirror with an aperture by hole output coupling. The cavity mirrors are spherical and gold-coated on copper substrate. The outcoupling mirror has a hole of 0.5 mm diameter in the center. Our alignment system concept is that the optical axis of two mirrors is adjusted to coincide with the electron beam position. The electron beam position in the beamduct of the undulator is detected using three OTR plates and images of OTR at the plates are observed by CCD cameras.
