Use of a bent crystal for beam extraction in a slow extraction mode

A bent Si crystal placed before the first septum-magnet (SM-18) of the IHEP accelerator (A-70) available slow extraction scheme allowed one to extract, for physical experiments, a part of protons that used to be lost at the septum-magnet aperture boundaries in the non-resonant slow extraction mode. In this mode up to 3.10/sup 8/ protons were extracted additionally. This is about 10-30% of intensity extracted towards channel No22 without the bent crystal. Use of unbent crystal as an amorphous target results in a decrease of the extracted beam intensity.