Transcript Diapositive 1

COMMISSIONING MEETING – JUNE 2008
PS/SPD COMMISSIONING
OUTLINE
1) PROGRESS REPORT.
2) PLANS.
3) CONCLUSION.
S.Monteil
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COMMISSIONING MEETING – JUNE 2008
PS/SPD SCHEME
LEDs or XCAL cosmics
Tubes response
VFE integrates signal
Transmission to FE Board
Digitalize and correct PS data
DAQ PATH @ L0
PSTELL1
EventBuilder
Recompute the trigger
response
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TRIGGER PATH @ 40 MHz
Trigger cabling
Build Trigger Information
Go to SPD CB
Go to Validation Board
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1) PVSS
PRSDAQ_X1
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PS/SPD COMMISSIONING
PSFEB project
improved with glue
resets included.
CROC project
improved with specs
master resets
included.
SPD CB project
improved with checks
of registers.
Configuration time is
an issue on C-side
(more than one
minute).
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1) PVSS
General comment: Since the global commissioning week, we only
took few sucessful pedestal runs (yesterday).
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2) PRS / VFE
The pedestal
corrections
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2) PRS VFE
The remaining DAQ/synchronisations issues in one shot:
VFE CLK KO ( 2 ½ boards)
PRS Noise in Prev2
COSMIC RUN 23989
(4 June 2008)
VFE SYNC ISSUE (3 boards)
DEAD CHANNELS
SAMPLING ISSUES ??
TO BE SCRUTINIZED …
PRS in T0
HV ON !
255+ PEDESTALS
(2 CHANNELS)
N.B: Both VFE ½ channels
are in Prev2
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2) PRS VFE
The noise performance:
C SIDE
A SIDE
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2) PRS VFE - Status
VFE CLK KO ( 1+½ boards)
PRS Noise in T0
PEDESTAL RUN 25178
(24 June 2008)
HV OFF
VFE SYNC ISSUE
(SOLVED A SIDE)
C SIDE VFE
DEAD
DEAD CHANNELS (2+)
CONFIRMED CAT
255+ PEDESTALS
(1+ CHANNELS)
N.B: 1 VFE ½ channel
only in T0
C SIDE
A SIDE
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2) PRS-SPD VFE - C-side power supply
1) VFE C RECTIFIER ILL FUNCTIONING (BLINKING LED)
 NO VFE POWER ON C SIDE ( brand new 24 June / some preliminaries …)
2) PUT SPARE C RECTIFIER IN VFE C SLOT
 MARATHON VFE C FUSED … more likely ( LED flash & then dead … )
3) VFE C RECTIFIER STILL ILL FUNCTIONING IN VFE A SLOT (BLINKING LED)
 RECTIFIER ISSUE / HAS BEEN TAKEN OUT
4) SPARE C RECTIFIER IN VFE A SLOT ?
 NOT TESTED … suspicious rectifier has been taken out too
SUMMARY:
1 DEAD RECTIFIER
1 SUSPICIOUS RECTIFIER (FUSED A MARATHON?)
MARATHON VFE C FUSED
Good News: SPARE-A DOES WORK!
PLANS: (WHO?)
1) DIAGNOSE/REPAIR MARATHON VFE C
2) PUT SPARE A RECTIFIER IN SLOT VFE C
3) DIAGNOSE/REPAIR THE RECTIFIERS
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3) TELL1
Used to take more than one slide.

Huge progresses since last meeting.

All faulty boards or components have been changed or repaired
and perform now well.

The overfull fifo / underfull bug are fixed.

We know that the event size is an issue at high frequency from
data generator studies. Test with nominal events still to be
performed.
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4) COSMICS DATA
We recorded several tenth of cosmics data with PRS and SPD,
either muon or XCAL triggered.

Both detectors were aligned in the correct bunch crossing.

All expected time differences are accounted for by dedicated
settings of the adequate phasers.

PRS pedestals were nicely subtracted for the main part of teh
channels.

SPD thresholds yield very few noise.

The correct mapping of the channels has been successfully
corrected in the software.
The first analysis : (see Ricci’s talk) yields encouraging results
in term of time pre-alignment,
time-alignment method as well
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PS/SPD COMMISSIONING
as cosmics efficiency.

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4) COSMICS DATA. The Prs weird events at the 1/1000 frequency
They occur always at the
same BCID (147 and 167 in
the runs we take).
It is likely that the trigger
comes close a VFE reset,
which makes the chips stuck
for some bunch crossings.
There, we are applying the
VFE+ADC pedestal correction
to ADC pedestal only.
In physics, VFE reset occurs
in a large machine sequence
of empty bunches.
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4) COSMICS DATA. The HV issue
We missed one half of C-side.
HV resistor blown on both SPD and PRS lines.
We have to be precise about the order of operation .
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5) TRIGGER PATH
Since PRS and SPD are time-aligned in the DAQ path, a large part of
the two last weeks was dedicated to include them in L0Calo.
We measured (at least we had strong indications) that the PRS/SPD
time budget was larger by several clock cycles than the expectation
(See Eric’s talk).
Two issues:
TVB pipelines are too short by more than 10 clock cycles and a
new firmware is needed.
The overall time budget of L0Calo is already close to the limit.
That won’t help.
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5) PLANS as a conclusion
We’d like to record this week a large number (> 100 k) of cosmics, to
exercise the time-alignment methods. At least A-side is fine.
Fix the C-side rectifier and Marathon.
Complete the work on the measure of trigger time budget. Still need
to robustify our numbers.
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