Agenda Announcements Paul 5 min Machine status Sasha

Agenda § Announcements (Paul, 5 min) § Machine status (Sasha, 15 min) § Final results of lattice measurements at zero trombone settings and at working point with the new trombone (Meiqin, 15 min) § Additional results of stochastic cooling rate measurements (Lionel, 15 min) § AOB ( 10 min )

Weekly Review of Operation Recycler departmental meeting January 23, 2007 2

Operation- ECool troubles § ECool had several unrelated problems last week (Jan 16 – 22) Ø HV became less and less stable and finally failed completely early Saturday morning. Ø Electron cooling rate was deteriorating even at moments of a reasonable HV regulation. Ø HV software regulation loop stopped working after attempts to improve it, but recovered after several times of front end rebooting. Ø Not working NMRs made unreliable the energy check based on trajectory.

Opening the Pelletron on Jan 19 -20 § Early morning Jan 19 the HV regulation failed completely Ø Mechanical techs came on a short notice and opened the tank Ø Because the spare board had not arrived, Kermit, Greg, and Jeff cleaned contacts of suspected chips and soldered one of them Ø Lionel went through the check list, and techs closed the tank Ø Total time with a low tank pressure was 24 hrs Ø Great team work § One store was put in with stochastic cooling only

Poor e-cooling § E-cooling was poor, as it was on Friday § One store was put in with ECool in this state § At 3 AM on Jan 21, Lionel started drag rate measurements Ø Drag rate was 5 - 7 Me. V/c/hr on axis vs recent 30 - 50 • Zero at 1 mm offset • All indicated large envelope oscillations Ø No dependence on quadrupole currents and settings of lenses B 01, B 02 § Finally, scan of SPA 06 lens shown that it is the culprit Ø Change 16. 4 A -> 18 A restored good cooling • Also, the lens voltage returned to its normal value Ø On Jan 22, Kermit found that the reason could be a failed protection circuitry • Was replaced today • So far, results are inconclusive

Operation – ECool (cont. ) § Presently, ECool rates seem to be good § Remaining issue: 3 ECool’s NMR sensors do not work Ø Chuck Schmidt, Kermit, and Brian Kramper are attempting to resolve the issue § This morning, ECool front end stopped responding Ø Rebooting, then restarting the data base, then multiple attempts to start the blower

Operation (cont. ) § Stan moved slightly the working point to look whether it improves the life time of a dense pbar beam, but moved it back because of other problems. Ø Will be repeated § V 427 had intermittent output Ø Stan and Mary made a 3 -bump around and set it to zero § Stan adjusted coupling § Mary saved few files for both RR and ECool § One of transfers was made with MI collimators partially in, and it once more resulted in poor transfer efficiency (75%)

In works § First stage of the study of cooling DC component of pbar beam (Lionel, Martin, Dan)) Ø Gate 1 -2 GHz Hor and 2 -4 Ver systems to the gap Ø Look for the amount of DC beam and life time § Tom Meyer is creating a new ACNET parameter calculating “real” number of pbars from R: BEAM and R: TSEP 1 Ø Based on an empirical Valery’s formula § Cons and Mary are preparing changes in sequencer Ø Setting up parameters of stochastic cooling system from a table after transfers to speed up the process Ø Telling to Accumulator sequencer how many transfers Recycler can accept