Fast Injection into the PS2

1. Fast Injection into the PS2 • Fast Injection for ions and protons • See also PAC09 paper • Used PS2 sequence and optics “ps2_nmc_sxorc_lessvert.seq” • But the older “ringWP_FInj_Dez05.seq” for the geometric data for the transfer line layout (see Christoph later on). PS2 meeting, 25 June 2009

2. Parameters Used Kicker rise/fall time relaxed since then: For ions (Christian C.): Smallest rise time: 5.8 µs Longest flat top: 0.54 µs For protons (Michael): Proton fast injection only for commissioning purposes. Rise and fall time: 1 µs Flat top: 2.3 µs PAC09 paper PS2 machine Quads: Assumed good field region: ± 100 mm Assumed outside dimensions: 1100 mm PS2 meeting, 25 June 2009

3. Aperture Calculations • Ax,y is the required aperture, plotted in the following graphs PS2 meeting, 25 June 2009

4. Layout and Apertures Injected Beam H-Plane 2 Septa Quad 4 Kicker Tanks Stored Beam V-Plane S-type L-type PS2 meeting, 25 June 2009

5. Kicker Parameters • For PAC09 optimised for fast rise time: • 16.6  travelling wave system • Short magnets of < 0.65 m • Two magnets in each kicker tank on previous slide • If agreed on present rise time, this can be relaxed: • 1 longer magnet per tank • Lower impedance magnets to provide more kick for the same voltage • However, can not increase field that much of S-type due to saturation (assume max field 0.025 T) • Can use 4 x L-type with lower impedance • Apertures take into account additional 15 mm required for ceramic chamber  PS2 meeting, 25 June 2009

6. Kicker Beam Impedance • Kicker beam impedance is likely to be an issue for high intensity beams. • Using a metallic comb structure as for the SPS extraction kickers MKE gives about a factor 2 impedance reduction and is probably not sufficient. • The alternative is to insert ceramic chambers with metal stripes, like for the LHC injection kicker magnets MKI. This requires at least an additional 15 mm of aperture in both planes. • A kicker length of maximum 1.3 m should be used to facilitate the production of the ceramic chamber. More information on kicker beam impedance requirements will be very useful before continuing a more detailed kicker design PS2 meeting, 25 June 2009

7. Injection Septa • Two identical septa, 55 mrad deflection each • Outside vacuum • Apparent septum thickness 33 mm • Multi-turn coil • Pulsed at 1 Hz J. Borburgh PS2 meeting, 25 June 2009

8. Injection Dump • The maximum injected intensity of 1e14 p+ at 4 GeV results in a deposited energy of 64 kJ • Not expected to cause any damage • To minimise activation of elements an injection dump can / should be installed. • Double sided • Smaller aperture than downstream dipole aperture (± 80 mm) • Most likely position is after a defocusing quad, about 17 m downstream of the kicker centre. • Optimisation remains to be done: • Required length and material • Position and aperture verification PS2 meeting, 25 June 2009

9. Conclusions • A first iteration of a fast injection system into PS2 has been made. • Several solutions exist within realistic hardware limits • Before continuing any more detailed design one needs: • Confirmation of the parameters used: emittances, quad dimensions, required aperture etc. • More information on the required kicker beam impedance for shielding • Future work on the septa: • Check of field deformation by eddy currents in the vacuum chamber • Development of pulsed multi-turn coil insulation • Real work on injection dump is outstanding PS2 meeting, 25 June 2009