Parallel operation of three internal targets of the IHEP proton synchrotron

Mutual effect of local distortions of closed orbit (bumps) and coordinate ranges of steady beam guidence onto targets of three channels in case of their simultaneous operation is investigated. Using an auxiliary bump, practically initial range (as in the operation of two targets) of their operation coordinates for any three simultaneously operating channels, as well as in case of their successive operation with fast or slow extraction on the flat top of magnetic cycle, is ensured. Compensation of beam betatron oscillation frequency shifts due to the joint effects of bumps and decrease in monitor sensitivity to the operation of ''alien'' targets permitted to improve beam stability during its guidence onto three targets at once. The effect of FES kicker-magnet on the improvement of time structure of extracted particles is investigated. Depending on the target operation conditions the quality of dump structure is improved by a factor of 2-4