Septum magnet with thin current sheet for the system of proton beam extraction from the IHEP acceleration

Septum magnet with 0.5 mm-thick current sheet, developed for the system of slow and fast proton beam extraction from the IHEP accelerator, is described. Septum magnet may be used in accelerators with high and ultrahigh vacuum. Thermal loss removal from the current sheet is performed by the peripheral cooling system at the expense of thermal conductivity mechanism. Cooling system sink is placed outside the vacuum system as well as the magnet core and excitation coil reverse conductor. The current sheet insulation is radiation resistant and permits heating up to 300 deg C. The magnet is characterized by low gas release in the vacuum volume under residual gas pressure of up to 1x10-8Pa. As refers to accelerated beam orbit the septum magnet may be adjusted with high precision: in radial coordinate-within± 5 mm limits, in angular coordinate ±2x10-3 rad. Septum magnet has undergone bench tests and made 40000 cycles under different regimes. The number of operaions exceeded 500 thousand at the accelerator with proton extraction under operating conditions