calorimeter: overview
DESCRIPTION
Trig. sum. Bank 0. Calibration. electronics readout chain. SCA (48 deep). SCA (48 deep). x1. Filter/ Shaper. Output Buffer. Preamp/ Driver. SCA. BLS. x8. Calorimeter. SCA (48 deep). SCA (48 deep). Bank 1. Calorimeter: Overview. Ursula Bassler. - PowerPoint PPT PresentationTRANSCRIPT
New Phenomena Meeting 10/11/01 Nirmalya Parua
Calorimeter: Overview
Preamp/Driver
Trig. sum
Filter/Shaper
x1
x8
SCA (48 deep)
SCA (48 deep)
SCA (48 deep)
SCA (48 deep)
BLSOutputBuffer
Bank 0
Bank 1
SCACalorimeter
Calibrationelectronicsreadoutchain
Ursula Bassler
Nirmalya Parua New Phenomena Meeting 10/11/01
Problems during Post-Shutdown Data Taking
• Problem with timing with respect to the beam.
• Frequent failures of BLS (base line subtracter) power supplies.
• Dead, noisy, hot electronics channels
• Problems in understanding ADC to GeV conversion.
3Collaboration Meeting - 13 Sept. 2001Nirmalya Parua
Mingcheng Gao,. ColumbiaNew Phenomena Meeting 10/11/01
Timing Studies: triple samplingsignal
time0 +1-1
comparison of energies measured at the nominal BX,132ns earlier/later: ratios allow to determine time offset more precise timing from comparison
with model
+ 81 ns + 97 ns + 113 ns
late/nominal
early/nominal
• • •
=0.77
=0.69
=0.78=0.82=1.04
=0.64=0.61=0.39
Mingcheng Gao
Nirmalya Parua New Phenomena Meeting 10/11/01
BLS Power Supplies
Put Magnetic circuit breakers on all BLS supplies.
•A total of 36 supplies (+spares) needs to be worked on.
• 10 are already done.
• We will finish this job in 3-4 weeks.
Nirmalya Parua New Phenomena Meeting 10/11/01
Dead, Noisy and Hot Channels•Lot of bad electronics channels were replaced during past few months.
•In particular during the supervised access of 2nd week of September ~ 400 bad channels were replaced.
•Data taken after run ~131000 are the cleanest .
•There is clear enthusiasm about reprocessing this data set with off-line hotcell killer (NADA) and corrected weight factor.
•More Hot cells were found by shifter’s using Examines.
• During Shutdown we plan to eradicate these.
Nirmalya Parua New Phenomena Meeting 10/11/01
Dead, Noisy and Hot cells
Replacing bad preamplifiers.Capacitance Vs. Limit Values (Sorted by Species) 07/21/01 - Ram Calaga
0
2
4
6
8
10
12
14
16
18
20
0 1000 2000 3000 4000 5000Capacitance
Lim
it V
alu
es
Series1
Series2
Series3
Series4
Series5
Series6
Series7
Series8
7 Nirmalya Parua New Phenomena Meeting 10/11/01
Alan Stone
Nirmalya Parua New Phenomena Meeting 10/11/01
using pulser with DAC=25k delay=0
T&C: x889, BLS: Base-2ticks, ADC: 0-sign suppressed
ADC measurement:
DAC=25k ADC counts: 6355
em channel
had channel
Ursula Bassler
Nirmalya Parua New Phenomena Meeting 10/11/01
Scope Measurement 1 em-channel (crate 8 ADC 6 BLS 0 Tower 3 Depth 3)
PreAmp Input at BLS-card
Shaper Output for ReadOut
DAC=25k shaper Output=2.2V SCA (after gain selection) 1.1V
Electronics Design: 4V in SCA = 32000 Adc counts
estimation: 25k = 1.1V= 8800 Adc Counts
-0.5
0
0.5
1
1.5
2
2.5
-4.00E-07 -2.00E-07 0.00E+00 2.00E-07 4.00E-07 6.00E-07 8.00E-07 1.00E-06
Volts
Volts
Nirmalya Parua New Phenomena Meeting 10/11/01
•This problem was later identified by Dean as 2 resistors on the BLS board put in the wrong order.
•So all ADC to GeV conversion should be corrected by a factor of 1.4
Nirmalya Parua New Phenomena Meeting 10/11/01
•Runs Database from August 7- October 4 is available at
\\D0server4\projects\CalorimeterElectronics\Tuts\Cal_Runs_databse\fpdb\cal.access
•Please look at the data and give us feed-back for hotcells, dead regions or starange behaviours.