Minutes of the Jan 13, 2006 Tevatron Dept Meeting * News (Ron) - The start of the 14-week shutdown *may* begin on Feb 27 (Monday) rather than March 1 (Wednesday). * Weekly Summary (Andreas Jansson) - It was another good week in terms of delivered luminosity - over 23 pb^-1. All stores were terminated intentionally, and 5 of the 6 stores had average initial luminosities at or above 150 E30 cm^-2 s^-1. Early in the week, the stores had poorer than usual losses and lifetimes, but the problem was solved by the week's end with proper tuning. The recurring CDF radiation alarm during the squeeze was eliminated by increasing separator voltages a bit at the troublesome time (when the B17 horz separator is at zero to switch polarity) in order to increase beam separation. A number of studies and maintenance task were done including: aligning the F17 collimator replaced last week (it is being used for scraping again), crystal collimator studies (now complete - the current crystal will be removed), testing a new orbit stabilization algorithm, 1.7 GHz Schottky investigation (a mixer is likely saturating), TEL beam-beam compensation, and several others described below. * TBT Coupling Measurements (Eliana Gianfelice-Wendt) - Eliana has successfully demonstrated her W62 application can be used for measuring and minimizing coupling at 150 GeV during HEP shot-setup. After kicking the beam and acquiring turn-by-turn BPM data, the application determines the coupling and can make changes to the SQ and SQA0 circuits that minimize the horz and vert tune split. This method should be faster and more robust than the current manual method of reducing the tune split. We hope to make Eliana's application the default operational method for minimizing tune-split after implementing some suggested changes and writing documentation for the MCR operators. We hope to extend this method to make coupling measurements up the ramp and through the squeeze. * Strength of Third Order Resonances @ 150 GeV (Yuri Alexahin) - Using BPM TBT data, Yuri measured the driving terms for various 3rd order resonances of the injection lattice. As expected, most of the 3Qx resonance arises from the S6 feeddown circuit, in agreement with MAD. The currently unused S6A0 magnet can be used to reduce 3Qx resonance strength. Although there is much more planning and study to be done, Yuri's results suggest that the SPS working point may be another possible option for Tevatron operation (in addition to the half integer working point also being considered). * Optimizing Skew Quad Settings for HEP (Jerry Annala) - Jerry repeated an end-of-store study to reduce skew quad currents and look at the impact on luminosity. In the previous study, only the skew quads were changed, but separators were not optimized. In the new study, Jerry also implemented new separator settings suggested by Yuri. D0 luminosity did increase ~2%, but based on the previous study, a larger increase was expected. However, there may be some confusion in the needed vertical separator adjustments that needs to be addressed. The results are still encouraging. * TEL Beam-Beam Compensation (Xiaolong Zhang) - During an end-of-store study, the TEL was used to tune-shift a single pbar bunch (A9). Using 1 A of electron current, the measured horz tune shift was -0.003 with very little impact on losses and bunch lifetime! Losses did increase with more than 1 A of electron current, but that may have been caused by a power supply instability. (The horz tune was also being driven down close to the 7/12 resonance.) Future studies include: trying to shift pbars and clean DC protons from the abort gap simultaneously with a single TEL; trying beam-beam compensation on a single pbar bunch in the beginning or middle of an HEP store. * Looking at Proton Synchrotron Oscillations with SBD (Alvin Tollestrup) - Alvin showed some results of fits and FFTs from bunch shapes obtained with the SBD scope. The scope was configured to look at P1-P3 every 4 minutes when it would trigger 2300 times (once every 6.2 ms). He showed the results as a demostration of what can be done - they will be buying a new scope with more memory so they can sample all bunches in this manner. When fitting for the bunch shape he gets good results using a function that is a "modified Gaussian" - it has additional terms to adjust the baseline, allow an asymmetry in the oscillation (around the centroid), and cut off the tails at the edge of the bucket. There are some interesting features that seem to change over time. * New ACNet Devices (Ron Moore) - Ron created new ACNet devices that show the *changes* in several popular bunch-by-bunch quantities (FBI intensities, SBD bunch lengths, recalculated flying wire emittances) after particular events in the Tevatron (open helix, start of ramp, start of squeeze, initiate collisions). At each event, the "parent" devices are sampled and the "delta" devices are set to zero. The new devices allow one to see bunch-by-bunch patterns of beam loss or emittance growth as it happens during the interesting periods, e.g., up the ramp, through the squeeze, or since initiating collisions. * Plan for the Week - Our plan was scrubbed due to a quench and cryo vacuum leak that has required warming the A4 house the find and repair/replace the damaged component.