Cooling Time Measurements Test Storage Ring M.P.I. Heidelberg 2-4 December 1998

Goals To measure to cooling times with an expanded electron beam varying : expansion factor electron beam density initial emittance of the ion beam

Machine Layout Similar to LEAR. L=55.4 m, 4 straight sections injection/ejection diagnostics electron cooling laser cooling (Qh, Qv) = (2.841, 2.799)

Electron Cooling Adiabatic gun with expansion Bmax in gun = 1 T B in drift section = 418 G Maximum expansion factor of 25 Cathode diameter = 9.525 mm Ie max = 200 mA (anode at ground potential)

Diagnostics BCT to monitor the ion beam intensity Longitudinal Schottky PU for longitudinal cooling times Ionisation profile monitor for transverse cooling times

Experimental Parameters Beta functions : 5.8 m at BIPM 5.4 m at ECOOL D = 0.3 m at ECOOL Multi-turn injection timing and septum adjusted to have larger emittances at injection C6+ at 6.108 MeV/c/u v = 0.114 c Eecool = 3.35 keV

Experimental Parameters

BIPM profile

Schottky Spectrum

Some Results on Transverse Cooling