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CDC ReadoutCDC Readout- upgrade for Higher Luminosity -
Y.Sakai (KEK)
29-Oct-2002 TRG/DAQ WS @OCU
Review of Status/Plan (based on materials from S.Uno/M.Tanaka)
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IntroductionIntroduction
CDC will work at L = 1035 → ?? x1035
with some mod/improvement (a la S.Uno)[ small cell type CDC with R>15cm]
CDC readout Electronics to be designed to work up to CDC Hardware Limit
(Basic assumption)
(T0 Timing device is not included here)
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Requirement: CDCRequirement: CDC
• Tracking: Position Resolution (~130um)• P-id: dE/dx (~6% for MIPS)
[ Trigger signals → not issue here (Y.Iwasaki)]
Higher Lum. Machine : higher beam current
High hit rate : 100~200KHz
Smaller Cell (~7mm? ← 15~18mm)Fast Gas (80~100um/ns ← <40)
Max. Drift time (Tmax) : ~100 ns ← 400ns
Basically same as present one
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CDC Hit Rate (present)CDC Hit Rate (present)
Radius = 15cm
• Hit rate of innermost part > 100KHz chamber itself is working
• Other layers: ~5KHz → OK with higher beam current (>20 times higher BG)
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QT Deadtime & EfficiencyQT Deadtime & Efficiency
QT conv. Dead time~700ns
~200ns
June-2002
Oct-2002
Innermost 2 layers QT board replaced
Num
ber
of h
its u
sed
in tr
ack
ChamberEfficiencyitself is OKwith >100KHzhit rate
Belle CDC
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Fast Gas : CHFast Gas : CH44
• dE/dx resolution : similar to He(50)/C2H6(50)
80~100us/ns
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CDC Readout RequirementCDC Readout Requirement
Time Info.T~130um/vdrift → 1.3~1.6ns (v=80~100um/ns) ~0.5 ns LSB (1 ns maybe OK), Range ~ 2Tmax
Charge Info.
Basically same as present one (except dead time)
Dynamic range: >40MIPSQ ~ PED << sig ~20%Linearity : < 0.5~1%
Min. 10 bits(11~12 preferred)
Dead Time/hit : CDC intrinsic = Tmax ~100ns < 500ns (10% @200KHz , ~Tmax preferred)Dead Time/trig. : < 3us (10%@30KHz)
Normal !a la Tanaka-san
“Pipeline”
CDC hardware limit
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Possible ChoicesPossible ChoicesTotal number of channels : ~15K (← 8.4+1.8K)
Preamp/Shaper : conventional one is OK
Digitizers
(I) FADC only - 100MHz, 8~9bit, data compression
(III) TDC + slow ADC - TMC based TDC + 10~20MHz FADC (10bit)
(II) “QTC” + TDC [TDC only] - Charge integ. QT: conversion dead time - TOT type: accuracy ok for dE/dx ?
thin & smaller : small cell size, less material
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(I) (II) (III)(I) (II) (III)
(A)(B)
M.Tanaka
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• 10bit 200MHz FADC• Performance : no problem• Power : problem ~1W/ch
• 100MHz,8bit? Possible just do it. No R&D required
• Alternative solution : Analog memory with deconvolution function ASIC low power!
Component for T & dE/dx measurements(I)Component for T & dE/dx measurements(I)
R&Dgoing on
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Component for T & dE/dx measurements(II)Component for T & dE/dx measurements(II)
(K.Tauchi)
Analog: preamplifier (Gain=1.5 mV/fC, 1.5ns rise)
Shaping: Pole-zero cancel. (25 mV/fC, 5ns 0-paek, <2% undershoot)
Discriminator: Baseline Restorer (fully differencial, AC cpoupling)
Q-measurement: Time-over-Theshold, Width ~log(Q) Full range 120 fC
ASDQ on Flex circuit
Chip: 5.4x3.9mm2 PQFP, Rad-hard analog bipoler 8ch, 40mW, Noise ~2300e (10pF inp.cap)
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• ASDQ+TDC(TMC based) System
is working• Enough performance for
timing measurement
• Need detailed study for
dE/dx measurement
&&
Timing resolution<1nsec
Component for T & dE/dx measurements(II)Component for T & dE/dx measurements(II)
(K.Tauchi)
(continued)
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FINESS
User I/O board COPPER (DAQ platform)COPPER (DAQ platform)
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• Conventional way– TDC TMC core 24ch/FINESS
96ch/COPPER– ADC 10bit 20MHz HFADC
8ch/FINESS 32ch/COPPER
FINESS development is on going (Trigger out to be considered)
Dense implementation ASIC(next. step)
Component for T & dE/dx measurements(III)Component for T & dE/dx measurements(III)
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• HFADC core (for ADC FINESS )– ~10bit– <20MHz– 0.5~4.5V
• TMC core (for TDC FINESS)– 0.2~1ns
• AMC core (for waveform sampler FINESS)– 64 samples– Analog BW < ??
ASIC core developmentASIC core development
TADC FINESS
ASIC with(ADC+TDC)
(goal)
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• L1 pipeline storage T.Higuchi talk• One example
This will be implementedin FINESS-proto for debug of COPPER
Component for COPPER I/FComponent for COPPER I/F
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Data Size Data Size (comments)(comments)
Belle CDC: ~ 2KB + 50 * cdccur0
→ ~10KB @L=1035
(~1250 hits)
(~3KB=375 hits @L=3x1033 (cdccur0=20uA)
(May-2001)
(now it is smaller)
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SummarySummary
We are looking for person/group to work on CDC upgrade for Electronics R&D and implement (work with Tanaka-san) and for Construction / installation
CDC upgrade for Higher Luminosity
Readout Electronics: requirements can be satisfied with available technology
R&D in progress, but still need more work
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• Possibility of new TMC development project using 0.18um CMOS processModification for our purpose may be…..
• Y. Arai san’s talk !!!Specification should be discussed asap
Additionally…Additionally…
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Belle CDC (schematic)Belle CDC (schematic)
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