An injector study for electron cooling at PETRA using a bunched beam

An increase in the luminosity of circular hadron-lepton collider HERA may b e achieved via electron cooling of hadrons in the PETRA-preaccelerator. The cooling of high-energy (15-20 GeV) protons requires a high electron beam c urrent (few amperes) with low emittances ( < 4 pi mm mrad normalized) to re ach reasonable cooling times of < 10 min. For this purpose a linac-based sc heme has been considered. Electron bunches from a magnetized thermal cathod e are longitudinally compressed, accelerated in a traveling wave structure and, after reducing their energy spread, subsequently debunched to match th e bunch length in PETRA. The entire electron accelerator, as well as the co oling section, is immersed in a kG magnetic field; matching is provided for the technically unavoidable gaps in the solenoidal field. This paper prese nts the status of the development of the magnetized gun, accelerating struc ture and different variants of the debuncher. (C) 2000 Elsevier Science B.V . All rights reserved.