Minutes of the Feb 9, 2007 Tevatron Dept Meeting

https://indico.fnal.gov/conferenceDisplay.py?confId=582

* (Two Weeks) Operations Summary (Bruce Hanna) - January 2007 had a record
166 pb^-1 delivered luminosity, but only 46 pb^-1 have been delivered over the
past two weeks due to a variety of problems around the complex.  There have 9 
stores spinning with initial luminosities in the range 86 to a new record 
278 E30 cm^-2 s^-1.  The Main Injector was down for nearly 3 days in order to 
replace a NuMI magnet that had a water leak.  During part of that time, the 
Tevatron kept store 5201 spinning until it was aborted after a (second) RF 
station tripped off.  While waiting for the MI, the remainder of the new 
Tevatron sextupoles were split off from the original supplies and connected to
the new ones.  Unfortunately, during the recabling work, an ion pump connector
at the A18 spool was broken and much of the beam tube vacuum from A1-A3 was 
lost.  Those houses were warmed up to 100K to boil off the nitrogren that had 
cryopumped onto the cold beam tube.  When starting up after recabling the
sextupoles, larger than expected changes were needed for the injection
feeddown circuits (see next topic).  Store 5208 was aborted unintentionally
on a spurious vacuum abort at C3; the C200 module and CIA crate controller
were replaced.  Store 5211 was aborted unintentionally when an MCR operator
accidentally pressed the "test/reset" button on the Tevatron Power Supply 
Loop Controller while preparing the Main Injector for access.  Store 5218 
aborted prematurely on a spurious C3 heater firing unit status reading; that's
the first time in 6 years that an HFU caused the loss of a store.  The
remaining HEP stores were terminated intentionally.  CHL was once again
glitched by a fault on Feeder 36.  The F1 pond pump failed; it needs to be 
repaired on a down day since it can not be isolated properly.

* New Sextupole Status (Jerry Annala) - 22 of 88 sextupoles on each of the SF 
and SD circuits have been connected to new circuits for correcting the second
order chromaticity at low-beta.  There are 12 new circuits/regulators located
in 3 service buildings.  Those elements still run as normal chromaticity
sextupoles for now, but soon the polarity of half will changed for the final
configuration. The b2 drift compensation was adjusted successfully to account 
for the missing sextupoles on SF and SD.  However, the tunes on the helix
at 150 GeV were quite different from expected.  The feeddowns were adjusted
at 150 and 153 GeV to account for the change, and there has been no negative
impact on operations.  To check for incorrectly wired elements on the new
circuits, the polarity is being checked by looking at the tune changes when
doing large 3-bumps through the sextupoles in question; no mistakes have been
found yet.

* Status of IPM (Andreas Jansson) - Many new ACNET devices have been created
for the IPMs.  The vacuum group is testing a new, larger controlled N2 leak
that will be installed in the tunnel eventually.  After much debugging of the
prototypes, the production DAQ boards should arrive within 1 month or so.
The horz beam profiles at 150 GeV can not be measured fully due to the
limited number of working channels.  Studies of injection lattice matching
will resume while waiting for DAQ boards.

* Crystal Collimator Studies (Dean Still) - Dean has been exercising the new
crystal during end-of-store studies.  After scanning through ~1/3 of the full
angle range, no evidence of channeling has been observed.  Additional studies
will be performed.  The crystal alignment was thought to be understood, but he
will revisit the possibility of misalignment.  Several visitors will he here
in late February to conduct a series of end-of-store and proton-only studies
with the crystal collimator.

* Plans for Next Week

   - Get back to delivering lots of quality luminosity.
   - Complete polarity check of new sextupole elements (Jerry, Alex - during
     shot-setup or proton-only)
   - Resume TEL-2 in-store studies after Marx Generator repair (Seva, Xiaolong,
Vladimir)
   - Lattice Matching Measurements with IPM (Andreas, during shot-setup or
proton-only)
   - New Pbar Cogging between Injections (Ron, shot-setup)

   - New 150 GeV Helix, tune-up up ramp and LBSEQ 15-18 on hold until we
understand the new sextupoles.