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1
The Calorimeter Upgrade

• Run I ? Run II
• increase of the Beam Energy
• E (TeV) 1.8 ? 2.0
• increase of the Luminosity
• L (cm-2 sec-1) 2x1031 ? 2x1032
• modification of bunch structure
• decrease of interaction time
• Dt 3.6 ms ? 396 (132) ns

this gap is too small to form trigger and
sample baseline
Run II No modification of the calorimeter
structure New Electronics due to timing
constraints

• DØ Calorimeter
• Uranium / liquid Argon
• 55000 channels
• ? lt4
• D? ? D? 0.1 ? 0.1
• ?(em) 15 / ?E
• ?(had) 50 / ?E
• Excellent Run I performances
• low noise 10 MeV
• linearity lt 0.5

SCA analog delay gt 4 ms, alternate
new low noise preamp driver

• Signal shaping with peak
• sampling time at 400 ns
• Analog buffering for 4ms
• before L1 trigger decision

Trig. sum
Bank 0
Electronic Calibration
SCA (48 deep)
SCA (48 deep)
x 1
Filter/ Shaper
Output Buffer
Preamp/ Driver
SCA
BLS
x 8
SCA (48 deep)
? Replacement of Preamps, Shapers, BLS ?
addition of SCA ? new calibration.
SCA (48 deep)
Bank 1
Additional buffering for L2 L3
Replace cables for impedance match
Shorter shaping 400ns
Switched Capacitor Array
Preamplifiers

• Not designed for simultaneous
• read and write operations

• Calorimeter preamp
• hybrid on ceramic
• 48 preamps on
• one motherboard

• similar to previous version except
• Dual FET frontend
• Compensation for detector capacitance
• Faster recovery time

? two SCA banks alternate reading and writing

• approximately deadtimeless
• to L1 rate up to 100kHz
• Only 12 bit dynamic range

driver
preamp
New output driver for terminated signal
transmission
FET
? low and high gain path for each readout
channel (X8/X1) ? maintain 15 bit dynamic range
Electronic Calibration System

• Expected Run II Noise contributions
• (compared to Run I)
• Electronics noise ? 1.6
• increases due to shorter shaping times
• (2 ms to 400 ns as ?t)
• decrease due to lower noise preamp
• (2 FET input as 1/ ? 2)
• Uranium noise ? 2.3
• decrease due to shorter shaping times (as ? t)
• Pile-up noise ? 1.3
• increase due to luminosity (as ? L)
• decrease due to shorter shaping times (as ? t)

• fast pulse similar to physics signal
• optimized calibration for various
• detector capacitances possible
• precision better than 1

Pulser linearity
Frédéric.Machefert_at_in2p3.fr
Pulse height
Run II calorimeter electronics performances
equivalent to Run I for a 10 times higher
luminosity .