PSB FOM Report B Mikulec for the PSB

PSB FOM Report B. Mikulec for the PSB operations and beam commissioning team FOM 30/03/2021 1

Activities Last Week (1) Tuesday: • New optics for the extraction transfer line uploaded in LSA; the new optics start in the ring allowing to control of the position/angle at extraction. • POPS-B tests: • • • New coefficients for the voltage regulation (RST) for rings 2/3. This led to an improvement of a factor ~3 -4 (expected: ~7 -8). The strange oscillations during acceleration of ~0. 4 G amplitude are unfortunately still present. The voltage regulation for rings 1/4 is more problematic due to a strange oscillation point around 35 Hz, which is close to the regulation frequency. On Friday some step forward Work ongoing… FOM 30/03/2021 2

Activities Last Week (2) Wednesday: • Energy matching per ring (Bdls) with PS • Special bending magnet trims included in YASP as optional ring correctors • The recently added shielding around LBS. BVT has improved the situation by ~ a factor 4, considered acceptable Throughout the week: • Continuation of injection process optimisation • • • Study some tails observed mainly in vertical profiles for LHC 25 Beta-beating correction after improvements in POPS-B regulation Resonance compensation, different working points Emittance measurements with old and new wire scanners RF optimisation on LHC 25 (long. emittance <1. 6 e. Vs) and MTE Beam-based extraction and recombination kicker waveforms (during night/weekend) FOM 30/03/2021 3

MTE • Working on clone to apply several improvements R 4: almost 600 E 10 p extracted, then sudden losses on R 4, probably due to 1 oscillating Finemet cell Improved resonance compensation Achieved ~3. 5 um vert. emittance • • Vert. position fluctuation along pulse due to distributor FOM 30/03/2021 4

Issues and Solutions Several beam interruptions last week mainly due to POPS-B trips, Linac 4 issues, issues with a couple of Finemet cells, injection and extraction/recombination kickers and different watchdogs. ü Extraction/recombination kicker issues solved Update of the FESA class to solve communication problems leading to EC Increase of over-voltage interlock limit (too tight) Ø Ø ü Watchdog problems understood and solved Wednesday reduced the Linac 4 low-loss low-energy transmission threshold from 71 to 70% slightly due to small decrease in measured RFQ transmission (see Linac 4 report) PSB injection watchdog: Ø Ø Hardcode 25 m. A Linac 4 current instead of using the value from L 4 L. BCT. 3113 On Friday determine correctly the gain for the PSB ring BCTs calculated from the peak current instead of the average intensity FOM 30/03/2021 5

Availability FOM 30/03/2021 6

Next Steps • Interventions on a few issues (ongoing this morning): • • Repair WIC connection to BR 2. BHZ 162. Trim access required Frontend exchange for BI 3. KSW Replace 2 Finemet cells FGC 62 + FGC 63 update, Pow. M 1553 update MTG update Bdl tuning POPS-B: continue working on improved regulation Continue beam setup: • Transfer improvements from MTE clone to operational MTE cycle • Intensity increase on MTE • Start working towards ISOLDE and AD FOM 30/03/2021 7