Fast extracted proton beams at low energies in the CPS East Experimental Area

To provide beams with characteristics required by the Energy Amplifier Test, the CERN PS had to deliver new beams, of low kinetic energy (0.6-2.7 GeV), low intensity (0.5-5×10⁹ p) and short duration (<500 ns) via the existing slow extraction channel, the transfer line currently used for 24 GeV/c beams and a slightly modified secondary line. These beams were delivered without impairing other CPS operations and, despite large operational differences, the other three East Area beam lines could alternatively be supplied with slow extracted beam, for half week periods, thanks to the short setting-up time of a few hours. This paper describes how such beams were produced: by (i) acceleration or deceleration of the injected beam in the CPS, depending on the requested energy, (ii) fast extraction using the usual slow extraction channel, (iii) careful optics adjustments and reduction of multiple scattering in the transfer line. The range of beam characteristics achieved, as well as the limitations encountered are also reported