Minutes of the April 21, 2005 US ROD meeting

Follow up on action items

  1. The dryer for the UCSB compressed air is now installed.
    Need to see if it helps going to lower temperature.

  2. Work on understanding reset problem on FNAL SR.
    Problem solved. There was a 46.7 Ohm resistor on FEC2CCUM that is not
    there on FNAL-MR. Remove the resistor, now works.
    At UCSB, no resistor in MR, 100 Ohm resistor in SR (!!!) Remove it.
    Done.

  3. Jim has not yet started talking to JT about scripting the
    comparison between ARCS and rod data.

  4. Visual inspection of new bad channels appearing on rods
    FNAL: see scratches in area near pickup point. Found debris on tool.
    UCSB: Of 6 noisy channels, 2 correlated with visible scratches (shorts).
    Suspect the pickup tool.

  5. Opens at FNAL can be seen OK, need to re-check UCSB
    UCSB: at warm T OK, but common mode noise still high.
    Still need to check low T.

  6. UCSB: MR down. Waiting for valve replacement. Done

  7. UCSB: Sort out problem with bad lemo.
    Only affects DS rod, so not terribly urgent, but should be followed up.
    Can't seem to find what problem is.

  8. UCSB: DS rod bad noise. But using modules that went through severe cycles.
    Need to put new modules on it and retest.
    On back-burner until modules become available.
    In the meantime take a couple of these modules off and see what they look like on ARCS.,br>

  9. UCSB: Redundancy test. Getting errors. Check with Ryan? Not clear.

  10. UCSB: Tests of rod 178 (header-error rod from FNAL) continue. Swap
    module that gives errors to try to correlate with either rod or module.

  11. Lt SW bug that causes bad pulse shape. Valeri on it.

  12. DS rod with 3rd cooling plate runs cooler, but T ~ 40 C on hybrid,
    T ~ 55 on DCU. Sent mail to experts for advice.
    Mark Raymond says that APV within specs of process -- although no real data on it.
    No news on DCU.

  13. UCSB: check if need additional delay for T settling in MR scenario like FNAL
    14. FNAL: Tested bunch of new HPK rods in SR. Two out of six have broken or shorted
    termistor. Strange because Lenny says that these are chcked on rod frame.
    Possibilities: bad check on rod frame, or bad connection through flat cable, or bad DCU on hybrid.
    Check module fast-test
    Probe with multimeter
    No news

  14. FNAL: two rods with sporadic I2C errors on SR. Check on MR.
    Rod 17 failed. This is was a rod that was bad before with HPK
    Reassembled with ST, still fails
    Other rod looks OK

  15. FNAL: add cooling loop to MR. Not yet.

UCSB

SR and MR have high noise. Did not further experiment with grounding.

FNAL

Yuri: lots of work on cut tuning. Used Vienna box macro with same
cuts. good reproducibility. Wants to tighten cut perhaps. Tony
says they are loose on purpose because takes 4 modes N times, and
fault is the OR of all of them. (As I write this straight out
of my notes i realize that this does not make much sense -- shouldn't
you have tighter rather than looser cuts if you are taking the OR?)
Some cuts relative, some absolute, just like Vienna box analysis.

Yuri proposes to not use DefectAnalyzer. Use macro like ARCS with
no fitting of pulseheight.
Advantage: much faster
Disadvantage: no XML generation
XML file is needed for database but also to compare bad channel lists
with ARCS and Vienna box (since one could think of modifying script
that compares ARCS with Vienna box, and this script goes off of XML file).
Yuri says: maybe summer students to add XML generation to macro.

Others point out that DefectAnalyzer has same algorithms as macro and makes
XML file. Also, fitting which slows down program can be turned off.
Clearly this needs more discussion.

Yuri also proposes MR scenario. See email.