Minutes of the Feb 5, 2010 Tevatron Dept Meeting

http://indico.fnal.gov/conferenceDisplay.py?confId=3111

* Weekly Operations Summary (Andreas Jansson) - There have been 16 attempted 
stores in the Tevatron, during the past two weeks, with 12 making it to HEP 
with aborting. There have been issues with emittance blow up at collisions, and
high losses in the squeeze.  These problems have been much improved on recent 
stores.   Other problems during this time include B11 separator sparks 
resulting from a fluorinert leak, an AAK1 pre-fire, stuck Kautzky valves, and 
some faulty instrumentation on a power lead on D0Q2.  There was also a failure
of a bolted joint on the Q6 magnet at D13.  There were many more problems with
less impact that were experienced while trying to return to operations after 
the Linac downtime.  Studies conducted during this time include TEL 2 studies,
a Pbar only store to measure parameters on the Pbar helix, at crystal 
collimator studies with the new multi-strip crystal.  There was also an 
investigation of the effect of the orbit position at the location of the 
sextupoles on the S4 circuits.

* Lattice Measurement (Alex Valishev) - Alex reported that the latest optics 
measurement data collected on 1/29/10 do not converge with the model as well 
as they usually do.  The errors between the model and the actual orbits are 
larger than normal by a factor of two.

* Crystal Collimator Studies  (Dean Still) - Dean reported on the first attempt
at crystal collimation in the vertical plane, which was also the first attempt
using a multi-strip  crystal.  Much time was needed to verify the controls and
instrumentation of the new goniometer, but a useful scan of the crystals 
angular control was done at the very end of the study.  Volume reflection was 
seen, with very clean data signals.  During the portion of the scan where 
volume reflection was active, the Proton Halo at CDF was reduced by a factor of
4, and the Proton Halo at D0 was reduced by a factor of 1.7.

* Recent TEL 2 Studies (Giulio Stancari) - A Proton only study was done to 
align the electron beam on a coalesced Proton bunch.  The electron beam was 
scanned horizontally and vertically to look for the minimum Proton loss points
where the beams are head on. This alignment agreed to within 0.1 mm with the 
alignment done with the BPMs.  They are now ready to measure tune shifts and 
spreads resulting from the TEL.  A 2 hour Proton only, and/or a 30 minute end 
of store study is requested.  The LARP goals is to establish that no harm is 
done to the store by turning on the electron beam.


* Plan for Next Week (All)

  - Deliver luminosity.
  - Possible shutdown day
  - Tune space study at collisions (source of differential coupling)
  - T-980 crystal collimator (Dean, 2-3 hrs EOS)
  - Bumper Magnet as gap Cleaner (Bruce, Elmie, 4 hrs proton-only)
  - TEL-2 gap cleaning (1 hr EOS)
  - TEL-2 beam-beam compensation (.5 to 1 hr EOS or 2 hour Proton only)