ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary...

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ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i HEPIC 2013 LBNL May 30 th , 2013

Transcript of ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary...

Page 1: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

ASIC needs for “observational cosmology”

Gary S. Varner University of Hawai’i

HEPIC 2013 LBNL

May 30th, 2013

Page 2: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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What’s in & out • Very broad topic; minimize overlap with 2

following talks

• Focus on UHE ν, CR detection in Radio

• To better clarify needs: – State of the art – Current developments – Future (anticipated) needs

• WFS in TeV gamma (CTA) [DRS, SAM, TARGET]

Page 3: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Neutrinos: The only known messengers at PeV energies and above

• Photons lost above 30 TeV: pair production on IR & µwave background

• Charged particles: scattered by B-fields or GZK process at all energies

• Sources extend to 109 TeV ! • => Study of the highest

energy processes and particles throughout the universe requires PeV-ZeV neutrino detectors

• To guarantee EeV neutrino detection, design for the GZK neutrino flux

Region not observable In photons or Charged particles

Courtesy: Peter Gorham [U. Hawaii]

Page 4: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Why Radio?? (Ultra-)High Energy Physics of Cosmic rays & Neutrinos

• Neither origin nor acceleration mechanism known for cosmic rays above 1019 eV

• A paradox: – No nearby sources observed – distant sources excluded due to

process below

• Neutrinos at 1017-19 eV

required by standard-model physics

galactic

extragalactic

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Radio Observation in dense media

1960’s: Askaryan predicted that the resultant compact cascade shower (1962 JETP 14, 144; 1965 JETP 21, 658): • would develop a local, relativistic net negative charge excess • would be coherent (Prf ~ E2) for radio frequencies • for high energy interactions, well above thermal noise:

• detectable at a distance (via antennas) • polarized – can tell where on the Cherenkov cone

neutrino Cascade: ~10m length

air

solid

RF Cherenkov

Page 6: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

In the last decade or so… radio detection techniques finally flourishing

1. Radio Constraints on UHE neutrinos 2. ANtarctic Impulsive Transient Antenna (ANITA) 3. Serendipitous observation of UHE CR 4. Tera-ton Initiatives (ARA, ARIANNA, …)

Won’t cover low E CR, other radio, Atmospheric Molecular Bremsstrahlung

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Page 7: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Detector Energy Scales – the tonne

(total weight 7,000 tons, but sensitive elements much less)

Page 8: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Detector Energy Scales – the kT

Page 9: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Detector Energy Scales – the MT

Pushing bounds of civil

construction

Page 10: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Detector Energy Scales – the GT

Page 11: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Detector Energy Scales – the TeraTonne

IceCube ~200M$

Simply scaling up??

Page 12: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Initial Round of Experiments • PRL 93:041101 (2004) limits published

Radio Ice Experiment (RICE) @ South Pole

Greenland Ice

• PRD 69:0133008 (2004) • Astropart.Phys.20:195 (2003)

Page 13: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Design for cosmogenic ν flux discovery

• Huge Volume of solid, RF-transparent medium: Antarctic Ice Sheet

• Broadband antennas, low noise amplifiers and high-speed digitizers to observe them

• A high vantage point, but not too high nor too far away

• First realization: ANITA (balloon altitude)

Page 14: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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ANITA concept

Ice RF clarity: ~1.2km(!) attenuation length

Effective “telescope” aperture: • ~250 km3 sr @ 1018 eV • ~104 @ km3 sr 1019 eV (compare to ~1 km3 at lower E)

~4km deep ice!

Typical balloon field of regard

Page 15: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Flight Payload Design

• Quad-ridged horn antennas provide superb impulse response & bandwidth (200-1200 MHz)

• Interferometry & beam gradiometry from multiple overlapped antenna measurements

A radio “feedhorn array” for the Antarctica Continent

~320ps Measured

Page 16: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Major Hurdles • No commercial waveform recorder solution (power/resolution)

• 3σ thermal noise fluctuations occur at MHz rates (need ~2.3σ)

• Without being able to record or trigger efficiently, there is no experiment

Page 17: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Strategy: Divide and Conquer

• Split signal: 1 path to trigger, 1 for digitizer • Digitizer runs ONLY when triggered to save power

Three key technologies:

1. Very low-noise (low power) amplifiers 2. Efficient, thermal-noise limited triggering 3. Low power, Gsa/s waveform sampling

Page 18: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Switched Capacitor Array Sampling

Input

Channel 1

Channel 2 Few 100ps delay

• Write pointer is ~4-6 switches closed @ once

20fF

Tiny charge: 1mV ~ 100e-

Page 19: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Example: LABRADOR performance (similar to other ASICs)

• Excellent linearity, noise • Sampling rates up to 4 GSa/s with voltage overdrive

2.6GSa/s

12-bit ADC

• 10 real bits (1.3V/1.3mV noise)

1.3mV

Page 20: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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A solar powered, airborne HEP experiment

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-3 Phi

2-of-2

5-10Hz @ 36kBy/evt

= 180-360kBy/s To disk

Prioritizer (+compress)

Few

eve

nts/

min

TD

RSS

Page 21: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Page 22: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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After full calibration – 100’s km downrange

<30ps timing

Page 23: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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A. Vieregg

Page 24: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Warning!!! Log Plot!

Page 25: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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ANITA3 – the “last” round

• Rebuild “space flight” readout instrumentation (half a decade old technology) • Threshold limited – new trigger ASIC (RITC) • New digitizer (LAB4) to go to longer waveforms • “going for broke” – ARA is successor

For December 2014 Flight New SURF & TURF

RITC LAB4 25

Page 26: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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How to “go big” ?

• Salt – Salt domes

• Ice – In situ (RICE AURA IceRayARA/ARIANNA) – Overflight (satellite) [high threshold]

• Silica sand – Lunar regolith (GLUE) [high threshold]

Page 27: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Askaryan Radio Array (ARA)

• Gusev and Zheleznykh proposed in 1983! • 100’s of km3 volume at GZK nu range • Inexpense extention to IceCube

Physics Goals

Page 28: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

ARA Readout Electronics (similar to ARIANNA)

• Uplink bandwidth (~1Mbit/s [wireless]) – First (test station) this season

– 1 detector station each of next 2 seasons after (building more) 28

Page 29: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Askaryan Radio Array

• ANITA trigger/digitizer electronics to ARA • “array crossing” waveform sampler (IRS) • Built “testbed” in mid-2000’s …. • Finally deployed in January 2011, taking data • First “station” January 2012

Development Milestones IRS, IRS2, IRS3 ASIC

ARA Test Bed

Page 30: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Neutrino Flavor/Current ID

• Charged/neutral current & flavor ID possible on subset of SalSA events • At least 20% of GZK CC events will get first order flavor ID • Detailed initial studies – looks very promising [BLAB ASIC – 64us deep

version of LABRADOR makes possible [NIM A591 (2008) 534]

Charged current (SM: 80%)

Neutral current (SM: 20%)

e 25% hadronic + 75% EM shower at primary vertex; LPM on EM shower

Single hadronic shower at vertex

µ 25% hadronic at primary, 2ndary lepton showers, mainly EM

Single hadronic shower at vertex

τ 25% hadronic at vertex, 2ndary lepton showers, mainly hadronic

Single hadronic shower at vertex

~2 km

1018 eV νµ

Page 31: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Directions for future ASIC R&D • Low noise amplifiers

– Lower noise figure, lower power

• Better triggering – Only a couple bits needed – Real-time noise correlator

• Deeper waveform sampling – Already at ~100us analog storage – Higher frequency?

• Lower power! – Solar, wind, ??? – Autonomous, robust comm links – Design for manufacture**

Page 32: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Why nattering on about power?!?

Page 33: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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“Obs Cosmo” Summary

ASICs as the way Forward: • Further discoveries will depend upon evolutionary improvements in the basic instrumentation, of which ASICs play a crucial role

• Interesting problems with much overlap in other disciplines (low noise, high speed, low power)

• “Funding problems” are often mass manufacturing or operations cost issues – room for further ‘enabling technologies’

Page 34: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Back-up slides

Page 35: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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A great idea that took a while to catch on

– 1962: G. Askaryan predicts coherent radio Cherenkov from particle showers in solid dielectrics – His applications? Ultra-high energy cosmic rays &

neutrinos

– Mid-60’s: Jelley & collaborators see radio impulses from high energy cosmic ray air showers – -- from geo-sychrotron emission, NOT radio

Cherenkov – Renewed interest: LOPES/Codelema

– 1970-2000: Askaryan’s hypothesis

remained unconfirmed – 2000-2001: Argonne & SLAC beamtests

confirm strong radio Cherenkov from showers in silica sand

– Salt (2004) & ice (2006) also tested, all confirmed

Saltzberg, et al PRL 2001

Gorham, et al PRD 2004

Page 36: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Particle Physics: Energy Frontier

• GZK ν spectrum is an energy-frontier beam: – up to 300 TeV center of

momentum particle physics

– Search for large extra dimensions and micro-black-hole production at scales beyond reach of LHC

� ν Lorentz factors of γ=1018-21

Std. model

Large extra dimensions

Anchordoqui et al. Astro-ph/0307228

GZK ν

Page 37: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Particle Physics: Neutrinos • GZK neutrinos are the

“longest baseline” neutrino experiment: – Longest L/E (proper time) for:

sterile ν admixtures & anomalous ν decays

• SUN: L/E ~ 30 m/eV • GZK: L/E ~ 109 m/eV

• Measured flavor ratios of νe:νµ:ντ can identify non-standard physics at source

νe:νµ:ντ

(1:1:1)! (5-6):1:1

Neutrino decay leaves a strong imprint on flavor ratios at Earth

Page 38: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Differential GPS Antennas

Solar cells for NASA equipment

32 Quad-ridge horn antennas - 200 MHz to 1200 MHz - 10 degree downward angle

8 low gain antennas to monitor payload-generated noise

ANITA electronics box

Solar panels for science mission

Battery box

ANITA-1 pieces

“instrument paper” arXiv:0812.1920 [astro-ph]

Page 39: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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9 x 260 samples = 2340 storage cells

Convert all 2340 samples in parallel,

transfer out on common 12-bit data bus

256 + 4 “tail” samples

Page 40: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

G. Varner -- Challenges in Radio Detection, Detector R&D WS @ FNAL 40

Large Analog Bandwidth Recorder and Digitizer with Ordered Readout [LABRADOR]

8+1 chan. * 256+4 samples

Straight Shot

RF inputs

Random access:

• Common STOP acquisition

• 3.2 x 2.9 mm • Conversion in

31µs (all 2340 samples)

• Data transfer takes 80µs

• Ready for next event in <150µs

• Switched Capacitor Array (SCA)

• Massively parallel ADC array

• Similar to other WFS ASICs analog bandwidth

NIM A583:447-460, 2007

Page 41: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Bandwidth Evaluation

Transient Impulse

FFT Difference

Frequency [GHz]

f3dB ~ 1GHz

Page 42: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Sampling Unit for RF (SURF) board

Page 43: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

G. Varner -- Challenges in Radio Detection, Detector R&D WS @ FNAL 43

SURFv3 Board

Trigger Inputs

Programming/ Monitor Header

RF Inputs

LAB3

J4 to TURF J1 to CPU

(SURF = Sampling Unit for RF) (TURF = Trigger Unit for RF)

Flies in space – all components heat sunk

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Page 44: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Quiet, but are we sensitive?

Ground pulser

Dipole

Bore hole pulser

Page 45: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Validation data: borehole pulser

• RF Impulses from borehole antenna at Williams field

• Detected at payload out to 300-400 km, consistent with expected sensitivity

• Allows trigger & pointing calibration

Page 46: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Page 49: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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Page 50: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

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S. Hoover

Page 51: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

Askaryan Radio Array (ARA)

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Page 52: ASIC needs for “observational cosmology” · ASIC needs for “observational cosmology” Gary S. Varner University of Hawai’i . HEPIC 2013 . LBNL . May 30th, 2013

Cluster Station

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