Instrumentation for a Large, Underwater Liquid ...sdye/doanow_talks/GSV_DOANOW.pdfInstrumentation...
Transcript of Instrumentation for a Large, Underwater Liquid ...sdye/doanow_talks/GSV_DOANOW.pdfInstrumentation...
Instrumentation for a Large, Underwater Liquid Scintillator
DetectorGary S. Varner
University of Hawai’iMarch 25, 2007
XxxxXxxx Electronics and Communication, DOANOW March, 2006
Instrumentation Issues1. 3 examples of current developments in detector
readout electronics and communications2. Estimate of data rates for a large liquid
scintillator detector (XxxxXxxx)3. Related developments as proof of principle4. Future possibilities in single photon detection
2XxxxXxxx Electronics and Communication, DOANOW March, 2006
μ / KL detection14/15 lyr. RPC+Fe
Tracking + dE/dxsmall cell + He/C2H5
CsI(Tl) 16X0
Aerogel Cherenkov cnt.n=1.015~1.030
Si vtx. det.3 lyr. DSSD
TOF counter
SC solenoid1.5T
Belle DetectorBelle Detector
8GeV e−
3.5GeV e+
Example 1
3XxxxXxxx Electronics and Communication, DOANOW March, 2006
Belle DAQ Upgrade
At L = 1035 cm-2/s :• Pipelined readout: 128k channels equiv., 40MHz x 2bytes
10 Tera-bytes per second! (~2k DVDs per second)
Global Decision logic trigger: 10kHz• FIFO: 128k channels equiv., 16 bytes
20 Giga-bytes per second! (200 GbE links)
200 Mega-bytes per second!
COPPER, online Farm
(max. data rate to disc)
4XxxxXxxx Electronics and Communication, DOANOW March, 2006
• 32 Quad-Ridge horns and 8 monitor antenna• 2.6 GSa/s• Only a few hundred Giga-Bytes onboard storage• Satellite/LOS only
Another low-rate ν experiment
Example 2
5XxxxXxxx Electronics and Communication, DOANOW March, 2006
Trigger Reduction
Raw Signals
80 RF channels@ 1.5By * 2.6GSa/s
= 312 Gbytes/s
Level-1
Antenna
3-of-8
100-200kHz@ 36kBy/evt
= 3.6-7.2Gby/s
Level-2
Cluster
2-of-5
Few kHz@ 36kBy/evt= 36-72Mby/s
Level-3Phi
2-of-2
5-10Hz@ 36kBy/evt
= 180-360kBy/sTo disk
Prioritizer(+compress)
Few
eve
nts/
min
TD
RSS
Logical segmentation
L2 = 2 of 5
Top cluster
Phi = 0(1 of 16)
Bottom cluster
L2 = 2 of 5
Nadir clusterL2 = 2 of 3
(example Trigger Type = 1 shown)
6XxxxXxxx Electronics and Communication, DOANOW March, 2006
Radio in IceCube (AURA)1-2km
Utilize IC DAQ/Control Infrastructure
Example 3
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Toantenna
Toantenna
To
antenna
To
surface
ToCalibrationunitTo
antenna
Modified glass sphere 6 Penetrators:4 Antennas1 Surface cable1 Calibration unit
Radio BoardsUHF Sampling, Triggering, Digitizing, data processing, trigger banding, interface to the mb
MB (Main board)Communication, timing, connection to IC DAQ infrastructure,
Digital Radio Module (DRM)
8XxxxXxxx Electronics and Communication, DOANOW March, 2006
TRACR
DOM-MB
Metal Plate
Antennas
DRM electronics
ROBUST
Sealing the DRM
9XxxxXxxx Electronics and Communication, DOANOW March, 2006
AURA Data Rate
Each Node: dedicated communication link
• Each node self-triggers• Event size
– 9 channels/260 sample– ~2kB/event
• Link limitation– About 25 Hz
• Build event at surface– Something like 3σ– 100 nodes 5MB/sec
11XxxxXxxx Electronics and Communication, DOANOW March, 2006
Strategy for low-E threshold
Possible to record eachPhoton/process at surface?
PMTOutput
10kHz40 kB/s
64-channelProcessor
Board
Dua
l (re
dund
ant)
link
to s
urfa
ce
2.6 MB/s21 Mbit/s
2 MasterNodes
~2k PMTs
32-concentratorNodes
655 Mbit/s
10Gbit/s link~100kHz
12XxxxXxxx Electronics and Communication, DOANOW March, 2006
Existence Proof: Saltdome Shower Array (SalSA) Design studies
1
2
3
4
5
6
7
Depth (km)
Halite (rock salt)• Lα(<1GHz) > 500 m w.e.• Depth to >10km• Diameter: 3-8 km• Veff ~ 50-350 km3 w.e.• No known background• >2π steradians possible
Antenna array
• Rock salt can have extremely low RF loss, as radio-clear as Antarctic ice• ~2.4 times as dense as ice• typical: 50-100 km3 water equivalent in top ~3.5km =>300-600 km3 sr w.e.
13XxxxXxxx Electronics and Communication, DOANOW March, 2006
Basic string architecture
String12 nodes
Node = 12 antennas and center housing
tape
Stainless tube
armor
Insulatedconductors
Fibers
NEMA 3R38" x 21" x17"
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GEISER Data flow [NIM A554 (2005) 437-443](Giga-bit Ethernet Instrumentation for SalSA Electronics Readout)
Digital Cell system for data collection
Internal FPGA: Logic, Buffer
RF inContinuous
64kb/event16kHz (Gbit
Ethernet)
Trigger packets sent via FM/local
radio
Node/String Time stamps
Event requestFinal Data Transfer
Hold event if >2.4σ
antennas
asic digitizerCentral control &
Global Triggerstation
In salt
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What I can’t/can show
• HV, Digitizer, Fiber-optic communications board development/testing
• Similar studies for Particle ID studies– Custom ASIC for low power operation
– Using FPGA (programmable logic) as Discriminator, TDC and QDC
Journal of Instrumentation, Volume 1, P07001 (2006)
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ASICs for good timing/QDC
5-10W<= 0.05WPower/Chan.
8/7.412/9-10Bits/ENOBs
2 GSa/s1-3.7 GSa/sSampling speed
CommercialLABRADOR
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Similar Solutions
TDCPerformance
~0.37ns
Comparison: STaR vs. CAMAC y = 1.0174x - 1.3038R2 = 0.9996
0
10
20
30
40
50
60
0 10 20 30 40 50 60
CAMAC Charge [pC]
STa
R A
DC
Cha
rge
[pC
]
Run 1Linear (Run 1)
QDCPerformance
Belle TOF upgrade
Focusing DIRC proto
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Large area single γ detection
• PMT technology has stalled
•• New ideas: compact, small cell array New ideas: compact, small cell array (CRT vs. plasma )(CRT vs. plasma )
• Other recent developments– Large area APD (low gain)
– Augment with GEM structures
– Silicon PMTs (small, high dark count)
Issue is to get cost down
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Summary
• Similar (more challenging) comparative systems shown– Performance and power measured
– Results published later
• Technologies mature– Building on existing, similar systems
– Can always improve
• Future directions– Improved photo detectors
– Event builder demonstration