attività gruppo jlab12/iss · 2021. 1. 9. · fastbus expected performance and status 6 we can...
TRANSCRIPT
Outline
• Experiments Setup and DAQ configuration
• Fastbus for SBS: performance and status
• GEn/GMn - trigger and DAQ
• GEp - trigger and DAQ
• GEM readout
SBS DAQ
E. Cisbani / INFN Sanità
SBS DOE Review
4-5/Nov/2014 - JLab
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Main guidelines
- Reuse available equipment (Fastbus) to reduce cost
- Exploit JLab CODA3 VME hardware (FADC ...)
- GEM readout based on APV25 + MPD
Contributions from: • Sergey Abrahamyan • Alexandre Camsonne • Mark Jones • Bob Michaels • Paolo Musico • Igor Rachek • …
Experimental Setup 4/N
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Neutron form factor (GEn/GMn) Reaction : Quasifree electron
scattering on 3He or 2H
Trigger: Single arm electron
Electron singles rate: <5 kHz
Electron arm:
• BigBite Magnet
• 4 GEM chambers (FT)
• Gas Cerenkov (GRINCH)
• 1 Large GEM chamber (BT)
• Scintillator paddle array
• Preshower/Shower Calorimeter
Hadron Arm:
• Super BigBite Magnet
• Coordinate Detector
• Hadron Calorimeter
Proton form factor (GEp) Reaction : Elastic electron-proton
Trigger: Elastic ep coincidence
Electron singles rate: 200 kHz
Hadron singles rates: 2 Mhz
Coincidence trigger rate: 5 kHz
Electron arm:
• Coordinate Detector
• Electron Calorimeter
Hadron arm:
• Super Bigbite Magnet
• Front GEM tracker (FT)
• Analyzer
• 5 Rear GEM tracker (BT)
• Analyzer
• 5 Rear GEM tracker (BT)
• Hadron Calorimeter
DAQ configuration for SBS experiments 4/N
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• Reuse the NIM and Fastbus equipment already available at Jlab
• Exploit the new JLab CODA VME hardware for the «rest»
FASTBUS for SBS experiments 4/N
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Struck Fastbus Interface (SFI) is the Fastbus Master (18 available at JLab) • Allows control the Fastbus modules through any VME CPU. • Had slot for standard JLab Trigger Interface Module
64 channel Lecroy ADC 1881M (113 available at JLab) • 9ms encoding time in 12 bit resolution and 12ms in 13 bit resolution. • GEp experiment will use the fast clear feature in which the module is ready to accept another
event after 1ms.
96 channel Lecroy TDC 1877s (236 available at JLab) • Built-in Data Zero Suppression and Data Compaction (sparsification) • Capable of multihit with an event buffer of 8 events. • Encoding time 1.7ms plus 50 ns per hit per channel giving a maximum encoding time of 78ms. • Fast clear settling time < 250ns
Fastbus Crates holds up to 25 modules (30 available at JLab) Plenty of FASTBUS modules but: Fastbus standard transfer rate: 40 MB/s (sustainable 15 MB/s) 25% dead time at 5 kHz
Need to reduce Fastbus dead time!
Co
mm
on
Sto
p
background
signal
window 0-32 µs
sparsify Gate
Triggers
Readout Overhead
Triggers
Readout Overhead
II. Event Blocking (8 events in TDC and ADC)
Blocklevel=4 should work with pipelining VME
Buffers the deadtime
and reduces overhead
I. Sparsification (built-in feature in TDC and ADC)
Throws out background hits
III. Event Switching
3 parallel crates, triplicate equipment, but
reduces rate by 3
Status: tried, works
Status: tried, works
Status: test about to start
(expected to be straightforward)
Sergey Abrahamyan
Igor Rachek
Making Fastbus Faster 4/N
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4x(20+50) us
20+4x50 us
Fastbus expected performance and status
6
We can merge Fastbus with the rest of
the DAQ if:
• All components use blocklevel = 4
• All crates conform to the CODA
standard.
Needs to be tested
~10% deadtime at 20kHz
For a simple
level-1 trigger
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Two large Fastbus systems are being
assembled for test in the test lab!
TDC ADC Crate SFI
Have 236 113 30 18
Need 124 94 21 21
Neutron Form Factors (GEn / GMn)
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Neutron form factor (GEn/GMn) Reaction : Quasifree electron
scattering on 3He or 2H
Trigger: Single arm electron
Electron singles rate: <5 kHz
Electron arm:
• BigBite Magnet
• 4 GEM chambers (FT)
• Gas Cerenkov (GRINCH)
• 1 Large GEM chamber (BT)
• Scintillator paddle array
• Preshower/Shower Calorimeter
Hadron Arm:
• Super BigBite Magnet
• Coordinate Detector
• Hadron Calorimeter
BigBite Electron Single arm trigger (GMn,GMn) 4/N
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Use existing NIM logic for preshower/Shower coincidence
BigBite Shower Trigger 4/N
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S7 2 x S7 + S4
Shower 7 x27
Preshower 2 x27
S4
To discriminator
Bigbite trigger is OR of discriminated superblocks of
Shower +
Preshower
27 rows
27 rows
GEn and GMn: Hadron Arm DAQ 4/N
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• 2 VME switched Serial (VXS) Crates
• JLAB FADC250, 16-channel 12-bit
FADC sampling at 250 MHz
• Capable of 300 ps time
resolution in Hall D tests
• TS ( Trigger Supervisor)
• Accepts electron arm trigger
• Check status of all ROCs
• Outputs L1 accept as
• stop to TDCs
• gate for ADCs
• Readout signal for GEM MPDs
• Readout signal to HCAL TI
GEM/MPD’s
SSP
Electron Arm Trigger
Optical Link
L1A
L1A
See more, next in the GEp DAQ
Proton Form Factor (GEp) 4/N
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Proton form factor (GEp) Reaction : Elastic electron-proton
Trigger: Elastic ep coincidence
Electron singles rate: 200 kHz
Hadron singles rates: 2 Mhz
Coincidence trigger rate: 5 kHz
Electron arm:
• Coordinate Detector
• Electron Calorimeter
Hadron arm:
• Super Bigbite Magnet
• Front GEM tracker (FT)
• Analyzer
• 5 Rear GEM tracker (BT)
• Analyzer
• 5 Rear GEM tracker (BT)
• Hadron Calorimeter
GEp: Electron Trigger 4/N
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• Sum analog signals to form “superblock” of 4x8 blocks
• Total of 204 “superblocks” go to discriminators with threshold of 80-90% of elastic maximum energy
• L1 trigger is OR of the 204 superblocks logic signals
• 204 superblock signals sent to L2 trigger processor → next slide
Elastic electrons at Q2 = 12 at the
calorimeter
Ethr/Emax (%)
L1 Rate (kHz)
Data Rate (Mb/s)
50 3500 1400
75 320 128
85 120 48
50 ECAL blocks
GEp: Hadron Arm / HCAL DAQ and trigger 4/N
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HCal Signals to FADC inputs
Same acquisition scheme of GEn, GMn
Integrated signal and timing from FADC channels collected and sent to a General Trigger Processor (GTP) every 32 ns (over optical link)
GTP
compute all 4x4 sums of adjacent channels (HCAL clusters)
get electron Arm cluster information (204 superblocks signals)
check angular e-p correlation
If correlation send level 2 trigger to Trigger Supervisor → next slide
But now HCAL is in the trigger logic:
Gep: DAQ Configuration / both arms 4/N
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Trigger Supervisor • Globally controls readout of all crates • Receives T1 from ECal sends L1 to FASTBUS crates. The V1495
selects which group of FB crates to read out. • If T2 from GTP arrives then readout of VME crates and FASTBUS
( event buffer size of 4) • If no T2 then FASTBUS crates get Fast Clear
GTP
(GEM)
GEM – Readout Electronics D
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• Up to 16 APV25 cards (2048 chs) on a single MPD (parallel readout)
• Altera Arriga GX FPGA / RAM: DDR2 (128 MB) • Optical Link interface (either ETH 1Gb/s or Aurora 3.125
Gb/s protocol) • 110 MHz system clock and Front panel coax clock • Used HDMI-A connectors only for analog and digital signals • SD-card / All spare signals go to PMC compliant connectors • VME/32, VME64, VME64-VXS compliant • 4 high speed line on the VXS available for data transfer
Channels APV25 MPDs
Front Tracker 41472 324 24
Rear Tracker 61440 480 34
• 128 analog ch / APV25 ASIC
• 3.4 ms trigger latency (analog pipeline)
• Capable of sampling signal at 40 MHz
• Multiplexed analog output (100 kHz readout
rate)
MPD
MPD v4.0 VME interface performance
• All VME cycles tested including 2eSST (with STRUCK SIS-3104)
– 2eSST supported by new firmware release
– Readout speed measured by software: 100 transfer 4MB each. Data
integrity checked for each block.
– Bus speed is measured directly on VME bus
CYCLE
DATA period [ck] / [ns]
Bus / Simulated / Measured Speed [MB/s]
BLT (32 bit) 16 / 150 26.6 / - / 24.3
D64-MBLT 17 / 159 50.3 / - / 47.8
2eVME 20 / 186 86.1 / - / 73.6
2eSST160 6 / 54 142 / 148 / 117
2eSST267 4 / 36 213 / 222 / 124
2eSST320 3 / 27 284 / 296 / 124
Speed limited by SIS3104 2Gb/s
fiber connection
• Optical link with ETH 1Gb tested
• Optical link with Aurora protocol connected to SSP to be tested (no surprise
expected): speed up to 390 MB/s (sustainable 200 MB/s)
sustainable 200 MB/s
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Strip Occupancy: 60% Single MPD Transfer Rate: 45.2 MB/s (after sparsification)
200 kHz Rear Tracker – same occupancy and transfer rate
CDR rate estimation
• Expected Hits Rate (Front Tracker): 500 kHz • Samples/Events: 3 • GEM signal width: 250 ns • Cluster width: 2.5 strips • Trigger rate: 5 kHz
conservative
APV25 signal output
Real time data reduction needed !
Cluster Width
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GEp: GEM readout performance
Pure VME64 (original design) MPD + Optical Link + SSP + VME64
MPD/VME64 = 4
need 15 VME64 crates MPD/SSP=4, SSP/VME64=1
need 15 SSP, 15 VME64 crates
GEM Making Data smaller
• Deconvolution logic in the MPD (approx. 40% FPGA
resource available) – Deconvolution algorithm to time-correlation
at the level of 1/3 * 250 ns 80 ns
(can even use larger number of samples)
reduce data by a factor of 3
• SSP additional processing of the data – Geometrical correlation using BigBite & ep scattering & HCAL
information reduce the «signal area» to 40x40 cm2 (even smaller)
keep only information of 8+8 cards/chamber;
reduce data by a factor of 3 or more
– Further processing likely possible in SSP (e.g. clustering with x/y charge
correlation ...)
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Single MPD transfer rate = 45.3 / 3 = 15 MB/s Single SSP transfer rate with 32 MPD = 15 * 32 / 3 = 161 MB/s
Two SSPs on two separate VME64 crates
DAQ: Man power 4/N
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Coordination VME-DAQ Fastbus HCAL-Trigger GEM-MPD
A. Camsonne X X X X
M. Jones X
D. Adikaram X
R. Michaels X
B. Moffit X
B. Raydo X
V. Bellini X
E. Cisbani X
P. Musico X
J. Campbell (SMU student)
X
+ Support from JLab CODA and Electronics group
DAQ: Short Term plan
• Fastbus
– Crates switching test in progress: 3 months
• MPD
– Integration in CODA (partially done) need additional 6 weeks
– Deconvolution algorithm: 4 months
– Optical link protocol with SSP (proto-firmware of Aurora
available but not implemented): 4 months
• SSP
– SSP available, processing firmware development in 2015
• HCAL
– trigger development and testing: 6 months
• Small scale full setup Fastbus + HCAL trigger in 2015
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Summary 4/N
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Neutron Experiments Proton Experiment
• Single arm BigBite electron trigger at low
rate: reuse existing NIM / Fastbus setup
• High rate T1 triggers formation of T2 on
hadron arm
• Low rate L2 generated from: ECAL & HCAL
& ep angular correlation → trigger readout
• Fast Clear on Fastbus (if no L2)
Fastbus:
• Plenty of ADC, TDC and Crates
• Use sparsification, event buffering and crate switching to reduce dead time
VME:
• FADC amplitude and time information for HCAL
• MPD + Optical Link + SSP for GEM (smart processing in MPD and SSP to reduce data by 1/10)
JLab CODA3 hardware/software framework