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.