Beam Commissioning n Commissioning of transfer lines Three

Beam Commissioning n Commissioning of transfer lines Three settings proposed by Yann and Salim for the LNE 50 line have been tested by GBAR ¨ Beam sizes observed on their MCPs available – next steps? ¨ n Again study of effect of magnetic system of cooler on circulating beam Nominal currents reached for magnetic system of cooler ¨ Compensation solenoids used to compensate coupling ¨ Working point compensation refined ¨ n Chromaticity measurements Several studies with slightly different approaches give same result ¨ Positive natural chromaticity in horizontal plane!! ¨ n Chasing of extraction timing and synchronization problem ¨ n Automatic injection steering ¨ n Details see next slide Data (time traces of PU signals) from orbit system used to estimate transverse beam positions for first turns Acquisition of data from the orbit system for optics studies ELENA Commissioning Meeting CC, 30 th November 20 20

Hardware and Software Issues n Ion switch power converters Now using FUG converters, which cannot be pulsed and are not compatible with beam in old experimental zone ¨ Colleagues from TE/EPC working with company on improved protection against arcs expected to be available for restart next year ¨ Scheduling of installation of last set of spare converters to be discussed => Tomorrow and then concentrate on LNE 00 studies (TE/ABT readiness) ¨ n Extraction timing and synchronization timings Observed with h=4 cycles (but not limited to them) ¨ First time observed after re-programming again an injection after proper setting up of cavity servo loop for h=4 ¨ Attempts to restore by reloading all RF settings was not successful ¨ Explanation not found after thorough investigations with LLRF experts (Maria-Elena, thanks for having found some time despite pressure from PSB) ¨ Setting up of another h=4 cycle allowed to have (temporarily) h=4 beams properly extracted ¨ Cycle editor manipulations observed to create and re-solve the problem (now both h=4 cycles work) => Investigations to be done to understand the problem!? ¨ ELENA Commissioning Meeting CC, 30 th November 20 20

Tentative program for this week n Monday Morning: investigations on extraction timings ¨ Afternoon: coupling with LNE 50/GBAR ¨ n Tuesday ¨ n Access if possible only in the morning (upgrade of general timing system take place as well) Wednesday Morning: Acceleration and phase loop settings for different harmonics ¨ Afternoon: LNE 00 optics studies ¨ n Thursday Morning: ? ¨ Afternoon: LNE 00 optics studies ¨ n Friday Morning: Electron cooler (effect on circulating beam) ¨ Afternoon: LNE 00 optics studies ¨ n Other ¨ Automatic injection steering? ELENA Commissioning Meeting CC, 30 th November 20 20