Log entry time 15:48:16 on October 15, 2010

Entry number 335015

--- STATUS UPDATE ---

The LHRS trigger seems to be in good shape.  Event rates are in line
with expectations.  Several of the problems with the Calorimeter readout
seem to have been traced to a bad VME crate.  That crate has been
removed from the system, the cards redistributed to the other crates,
and the system seems much more stable.  There is still more to do on
Calorimeter DAQ, but steady progress is being made.

The BCM calibration was completed and we (should!) have the data on
disk.  The calibration procedure was a little scrambled though, and did
not follow the "playbook", so the data should be looked at soon to
verify we have everything we need.
  http://www.jlab.org/~adaq/halog/html/1010_archive/101014164656.html
  http://www.jlab.org/~adaq/halog/html/1010_archive/101015110155.html


Kalyan completed his Lumi-linearity test plan.
  http://www.jlab.org/~adaq/halog/html/1010_archive/101014194523.html

The helicity control board firmware (in the Injector) was changed
yesterday.  There seems to have been a glitch with the Helicity decoding
at one point, but it seems to be OK now.  Something to keep and eye on
though:
  http://www.jlab.org/~adaq/halog/html/1010_archive/101015085311.html
  http://www.jlab.org/~adaq/halog/html/1010_archive/101015090449.html



-- UPCOMING SHIFTS (Friday, Saturday) --

FRIDAY DAY shift is consumed by an Arc energy measurement, followed by a
Moller measurement.  This was to have started at 9am, but injector-related
work pushed the start time back to about 12:30pm.  The Energy measurement is
now complete (15:00) and returns an energy of
  Hall A Energy = 5548.91 MeV +/- 1.1 MeV
This is is good agreement with the nominal energy measures:
  Tiefenback Energy = 5551.7 MeV +/- 3 MeV
  Set Energy        = 5551.76 MeV
http://www.jlab.org/~adaq/halog/html/1010_archive/101015151917.html

The Moller procedure has now started and should take about a shift.

After the Moller (late Swing), we will return to debugging/commissioning
the Calorimeter and combined DAQ.  It will be largely expert-driven
(Alex, Carlos, Julie, etc).  This will continue into Saturday and
through the weekend.

Compton (Eric) would like to do a "Table scan".  This will take roughly
1 hour and will require modest beam current (20--30 uA).  This should be
run at a convenient time this weekend.



--- MONDAY (Hall will be open during DAY, part of SWING) ---

Beam will be OFF on Monday starting at 0700 so Facilities can do some
work on the LCW piping that supplies the Halls.   The Halls will be down
for roughly 12 hours (ie. until 7pm or so).  Hall A will be in either
Controlled Access, or in Restricted (Folts can choose).  Work to be done
includes:
  * Ramp down all magnets when beam turns off in the morning (0700)
    [Shift crew]
  * Prepare power supplies and other systems for the interruption to the
    LCW supply [Techs]
  * Swap polarity on the LHRS back to negative
  * Try swapping the NMR hardware in the LHRS with a unit borrowed from
    Hall C.  (Could help with the NMR lock instability.) [Jack]
  * Investigate the double-pulsing on the 1 kHz clock at the scalers
    [Kalyan]
  * Fill the Moller Dewar [Jixie, Sasha]
  * Bring the power supplies, etc back online when LCW is restored

There is a strong possibility that Hall C will attempt to correct a cyro
plumbing problem with their Moller during the Monday downtime.  If it
pans out, then the 4K flow will be shut off (at minimum, to Hall C) and
there may be disruption to the 15K flow that is supplying our target.
This interruption in the flow should be "short" and the experts think
the work can be done with mimimal impact to the other systems.
Nevertheless, we will need a target expert to 'safe' our target on
Monday morning (ie. minimize the load on cryo) and to keep an eye on the
system until the full cryo flow is returned and stabilizes.




--- LONGER TERM ITEMS ---
 * A full spin dance will be deferred to the following week (depends on
   how smoothly the Hall C Moller commissions)
 * LHRS polarity back to negative (Monday)
   - we need more sieve data (in particular) to complete the optics
     calibration on the LHRS
 * Compton (Eric) would like to do a "Table scan".  This will take
   roughly 1 hour and will require modest beam current (20--30 uA).