Weekly Review of Operation Recycler departmental meeting November 14 th, 2007

2 Pbar Monthly Totals Perhaps an overestimate

3 Status Summary – Transfers from Accumulator  Pbars to the Recycler  10 Shot setups 657E10 Pbars received from the Accumulator (in RR) –Measured in MI (to compare with pre-shutdown analysis) : 712e10 (i.e. only 92% efficient) »Better than last week »Before the shutdown, we were assuming 95% efficiencies ! »Average efficiencies Historical Last weekThis week –ACC to MI 95% 94% 97% –MI to RR 95% 92% 92% –‘Beg to End’ 90% 87% 90% »‘Storage’ 85% 89% 89% (in/out measured in MI) Downward trend throughout the week though ! One very much sub-par transfer (w/o bunch loss)

4 Storage efficiency and mining Mostly because of the one bad transfer

5 Status Summary – Shots to TeV  Pbars to the Tev  4 shot setups: 500E10 transferred (measured in MI) 125e10 Average Intensity per shot (down from last week)  All were partial mining stores  Average emittances Last week This week –Trans. Schottky (in RR)* –Trans. FW (in RR) * [  mm mrad] –Longitudinal (in RR) * –Long. (bunch in MI) [eV s] Average mining efficiency : 99% 64% * Before mining

6 Operational Highlights/Machine Maintenance  Worked on consistent procedure for partial mining  Simplified (and improved) Excel spreadsheet used to calculate the appropriate bucket height  Hopefully, we are only a few stores away from normal operation  Adjusted RF correction timing after RF reboot  Upgrade in the works to avoid this manipulation in the future  The ‘flatness’ of the bunch is not as good as before the shutdown Should we consider reducing the maximum RF voltage to gain more head room for the feed forward system ?  Horizontal Schottky calibration with scraper  No evidence of coupling This is different from the vertical scrape done a few weeks ago to calibrate the vertical Schottky detector (!?)  The change to the calibration was +6.5%  Changed $2D mini-dip by -3 MeV  Seems to help with injections

7 Operational Highlights/Machine Maintenance (cont’)  Timed in new dampers  Has been in for almost a week (connected to inputs only, not the kickers) Ready for operation (implementation next week probably)  HV oscillations on the Pelletron went away by themselves (since Friday evening) !?  Prepared specific diagnostics to be installed inside the tank when we get a chance to access  Separation box (to replace faulty one at the 1 MV level) has been tested and is ready for installation  Loss monitors tripped the electron beam (sometimes) during multi-batch slip-stacking studies  Intensity (and protons losses) will only go up with time This will be the standard event soon  Need to look at this new loss pattern and devise a plan to mitigate the impact of these losses on the electron beam operation

8 Issues - Recycler  One un-explained emittance blow up event  Ops cooled the stash deeper than typically…  … however, the phase density was only 2.3 (Schottky) Our current stability limit is supposed to be higher (see later slide)

9 SDA transverse emittances reporting issue  Emittance measurements in SDA are reported from R:EMHANM and R:EMVANM  These devices do not report the correct emittances when stochastic cooling in on Was always true but it is worst now with the 1-2 GHz vertical system  Question: How should we report emittances in SDA now ?  R110 emittances (or slow emittances i.e. R:EMITHA and E:EMITVA) may be adequate for shot to TeV although we can not guarantee the timing In particular if R110 measurement frequency is set to 12 minutes ! On the other hand, pin switches are supposed to be open during shots –But not before mining, which is the emittance reported in the summary table  R110 emittances are not adequate for transfers from the Accumulator Emittances were reported after each injection Vaia has been informed that we no longer need/want these devices reported in SDA

10 Studies highlights  Recycler  ‘Old’ dampers stability limit in a single bunch Found to be ~2.7 (Schottky) or ~4.2 (FW) for the phase density No beam loss  Effect of state 11 (i.e. anti-bucket formation and 2.5 MHz buckets manipulation during injection) on the longitudinal profile of the stored beam Repeated twice No visible effect (in particular, no shoulder/wing formation)  Ecool  Drag rate w/ high number of pbars Failed to achieve the adequate equilibrium (namely, ~2  mm mrad transversely, while maintaining a small momentum width)

11 Plan/Upcoming studies  Near term  Test stability limit of the new dampers (Martin, Sasha)  Measure longitudinal distribution of the injected beam (Martin, Chandra) May be revisited  Drag rate measurement with ‘large’ number of pbars (Sasha, Lionel) Need to add transverse noise to achieve adequate emittances  Optics measurement with electron beam (Mary) Need one more set (may be tomorrow)  ‘Old’ items not marked as completed in studies list  Rapid pbar transfer scheme (Chandra)  Electron cooling in linear bucket (Lionel, Sasha)  Recycler impedance measurement (Martin)

12 From Stan’s startup list  Calibrate/check RF voltage with synchrotron frequency measurement (Martin, Chandra)  Adjust compensation loop for new $20 ramp (Stan)  Document chromaticity (Stan)  Needs protons  Run pbars in boomerang mode (Stan, Martin, Stan)  Document beam motion with tune changes and correct/reduce if necessary (Meiqin, Stan)  Started yesterday evening  Lattice studies at operating tunes and ‘low’ tunes (Meiqin)  What ‘low’ tunes means remain to be determined

13 Long(er) term studies list  In proton mode  Characterize Recycler abort (Dave Johnson) For Nova project