Minutes for Small Angle GDH Meeting, click here.
    Minutes for A1n Analysis Meeting, click here.
    Minutes for g2n Analysis Meeting, click here.
    Minutes for GDH Meeting, click here.
 

    Tentative Date of next Collaboration Meeting:  August 8-9, or 15-16 2002
 
 

    Kees de Jager opened the meeting by discussing the schedule:

•  The septum magnet progress is slow
•  The June 15th delivery date will not be met, so the first magnet will go
         to the hall to be cooled down
•  SAGDH will not be able to run in November and December because G0 will
         need polarized beam, and no other halls will be able to use 3 GeV beam
•  Kees suggested that the collaboration should consider the minimum amount of
         beam time needed to run the experiment
• Possible running times:
•  Run part of experiment in October 2002, and finish after Parity in 2003
•  Run in August 2003, after Parity (depends on G0 running in Fall 2003)
•  Run in next gap of G0 run (early 2004)
• Note:  Collaboration needs to supply enough manpower to setup ³He target in July

• Cell Status:
•  "ice cone" cells:  no good cells yet, needs full priority
•  "standard" cells:  ~ 3 good cells, production on hold
•  c1720, thin wall:  2 made by Mike, production on hold (1 gone, 1 unfilled)
•  Important to produce a "ice cone" water cell for tests
•  Run Plan:
•  Possible switch the 6 and 9 degrees sides of the "ice cone" cell
•  "New" accelerator schedule has 3 GeV running between 1.6 and 2.0 GeV
•  Added elastic runs (9 degrees, 1.6 and 2.0 GeV)
•  Empty cell runs to check wall contamination and radiative tails
•  Only one positron run at the end of the experiment
•  Things to do:
•  At least 2 runs per setting
•  Extend 1.6 GeV data taking to larger nu
•  More detailed document
•  Alternative run plan (1 septum, 1 angle, ...)
•  Prioritize a minimum set of kinematics (need 3 GeV)

    Paul Brindza discussed the status of the septum magnets:

•  Four good coils with all pieces at BWXT
•  Software:  Second version of PLC complete.  Operation software is
         in development and testing stage
•  Yoke and coil of first magnet complete.  LN2 shields added and fit checked
•  Yoke # 2 machining complete, waiting to finish the first magnet
•   JLab's preparation work is well advanced for delivery of magnet
•  Magnets will not be tested before putting them into the hall
•  Expected delivery of first magnet: end of June,  Paul doesn't expect
         until end of July 2002
•  Septum # 2, Paul expects by late September 2002!
•  Magnets will take about 2 weeks to install and cool down

•  ~ 11 weeks of design completed by Susan Esp
•  ~ 17 man weeks of work until completion
• Collimator support is about 10% complete (4 weeks)
• Need to prioritize and get more resources

    Steve Lassiter discussed the field clamp simulations:

•  Finished simulation including septum magnets, field clamps, and helmholtz coils
•  The Bz component of the field will be 8-11 G, a factor of 2 decrease on H0!
•  Result with no clamp and no holding field, gives a gradient for
         By = 77.3 mG/cm, and Bx and Bz ~ 0
•  With the clamp By = 11 mG/cm
•  Steve will simulate the septum and helmoltz coils without the field clamp
•  If the gradient from any component is too large, compensation coils will be used

    John LeRose gave an overview on the Septum controls:

•  Scott Higgins assigned to implement Septum magnets into EPICS
•  Basic tools (essential to run)
•  on/off, Iset/Iout, and interlock status
•  Expert screen
• Field readout (direct clone of HRS Dipole NMR screen)
• Update "Standard Hall A Tools"
•  Extra line for septum (each spectrometer)
•  Modified P0 set (for each angle)

    Doug Higinbotham discussed the Septum Optics commissioning:

•  The full septum comissioning time has been scheduled before SAGDH
•  No 3 GeV because of Hall B
•  Sieve slits will be put in and out by hand
•  Since there may be no 9 degree data, we should study the flux of 2 septum Vs. one
•  No field mapping before the experiment due to the delay in delivery

•  Experiment will use standard detectors for both HRS
•  FPP in HRSL (?)
•  No S0 or aerogels (needed for hypernuclear)
•  Summer checks:  detector checkout (Vince), upgrades as needed,
         experiment monitoring, and avoid "stupid" problems
 

•  Use new "G0" standard
•  Check A1n/g2n electronics (maybe disassembled)
•  "G0" test run needed, early July

    Arun Saha discussed the Beamline:

•  A BCM calibration was done for super-Rosenbulth
•  Another should be done for SAGDH
•  Use OTR and Harp to monitor beam position and profile

    Matt Poelker discussed the polarized beam:

•  Experiment requirements include 15 muA with high polarization, parity
         quality with independent control of feedback, and independent current ramping
•  Need to give beam requirements changes to the source
•  Independent IA (intensity asymmetry controller) and piezo mirror installed for
         tests at Hall A
•  Feedback via epics can be implemented now
•  g0 to begin 10/02.  Finding proper machine settings may result in tune-time

    Sirish Nanda gave an update on the compton polarimeter:

•  Mirrors replaced and compton now works
•  Resident in FEL group, expert on compton optics
•  Root based analyzer installed, first experiment to try out
•  Training: co-experts needed to run compton at 1 shift per day
•  Alexandre Deur suggested moving the compton computer and cameras to
         the DAQ room of the Counting House

    Eugene Chudakov discussed the Moller Polarimeter:

•  The detector will be replaced during the summer
•  Systematic error from the measurement is 3.4% (largest from magnetization measurement)
•  Magnetization measurements at JLab and SLAC:
•  One 50 um foil measured with both methods at B > 70 Gauss
•  Results match within about 0.5% relative

    Ole Hansen discussed analysis software:

•  For C++ analyzer status:  prelim. tracking code working, and has output trees
         and basic histograms (no cuts)
•  Things to do:
•  Bring tracking level to level of ESPACE (2 months)
•  Physics computations (1 month)
•  Flexible histogramming with cuts and expressions (2 months)
•  Missing items:  FPP, systematic PID, and many subtleties
•  New version of ESPACE:  uses left/right naming convention,
         aerogel and PR included, faster tracking code, and ready for use

    Nilanga Liyanage discussed online monitoring:

•  Ten days of commissioning to test
•  No major difference since last year.  Same online histograms
•  Use new version of ESPACE, which includes column-wise ntuples
•  Need new database for optics
•  Alexandre Deur will setup online monitoring

•  New G0 helicity electronics not ready
•  Faster DAQ:  3 kHz per arm at 25% DT seems achievable
•  Need to check DAQ with beam
•  Scalers:  have synchronous scaler events
•  Feedback: Joe Grames, Bob Michaels responsible, HAPPEX quality,
         and Feedback on position