Minutes of the May 11, 2007 Tevatron Dept Meeting

https://indico.fnal.gov/conferenceDisplay.py?confId=834

* Weekly Operations Summary (Dean Still) - We delivered 29 pb^-1 to CDF and D0
this week.  Luminosities were down due to our request for reduced proton
intensities and a shutdown day for safety system tests and various accesses.
There were were 6 stores with initial luminosities between 149 and 188 ub^-1/s.
Only 1 store was lost prematurely - store 5415 was lost 1 hour before its
intended termination due to a spurious fast QPM abort @ F4.  Our biggest
problem was the proton lifetime @ 150 GeV during pbar injections since
implementing the new sextupole configuration (more below).  During the Tevatron
4 hour access, a number of minor jobs were done including - reintegrating the
repaired B3 power supply, swapping the A1 & A2 QPMs to diagnose a network
problem, switching the polarity on the new sextupole circuit elements in 
F-sector and Transfer Hall, various maintenance tasks.  An attempt was made to
improve the noise on the A1 BLMs read out with the new electronics, but no
benefit was observed. There were parasitic TEL-1 studies during a couple of HEP
stores; all other studies were for improving operation with the new sextupole
configuration.  Alex Valishev proposed implementing a D0 alpha bump @ LBSEQ 16
to reduce losses at that point, but that study was interrupted to the Transfer
Hall electrical safety system dropping out - a bad key cylinder in the MCR key
tree was identified and replaced.  Separator scans for HEP provided a small
increase to the D0 luminosity.

* Discussion on Progress Operating with New Sextupoles Off - The proton
lifetime was really suffering (< 3 hr) during pbar injections due to some
apparent increase in beam-beam effects which are not fully understood.  A new
helix was introduced to increase the (vertical) separation at the suspected bad
parasitic crossing point.  Both proton and pbar lifetimes improved after
testing and implementing the new helix, but some additional tweaking needs to
be done.  Yuri will analyze the resonance driving terms using the optics data
Alex obtained with turn-by-turn measurements.  Implementing the new helix was
complicated by the B11 vertical separator needing to be in the opposite
polarity.  Losses at the C49 separators are still high early in the ramp.

* Plans for Next Week 

   - Deliver quality luminosity to CDF and D0.
   - Continue improvements after implementing the new sextupole configuration.
   - HEP tune mult calibration (Ron, end-of-HEP)
   - Chromaticity Tracker studies (Tan, proton-only)
   - TEL-1 beam-beam studies during HEP
   - Crystal collimator (Dean, end-of-HEP)
   - AC dipole measurements (Ryoichi, proton-only)
   - New pbar cogging during injection (Ron, shot-setup) 
   - ...