Two-Turn Extraction from an Injector Synchrotron

For a fast cycling synchrotron injector (booster), a significant cost reduction, mainly related to rf requirements, may be obtained by reducing the booster cycling rate. For this reason slow cycling synchrotrons with multiturn extraction have been considered for the purpose of a booster injector. The disadvantage of time dependent beam emittance and beam intensity during the extraction process is well known. With two-turn extraction this problem can be avoided making it still possible to reduce the booster cycling rate by a factor of two. Specifically for the 200-400 GeV NAL accelerator booster synchrotron, two-turn extraction has been studied and results are reported here, mainly related to extraction losses, betatron oscillation tune tolerance and extracted beam effective phase space dilution or beam transfer losses.