Cosmic Ray-Based Scanning: Techniques and ...

ANS Las Vegas Chapter Meeting, Oct. 27, 2016

DOE/NV/25946--3053

Cosmic Ray-Based Scanning: Techniques and Detectors J. Andrew Green, Ph.D. Principal Scientist – Remote Sensing Laboratory – Nellis National Security Technologies

This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy and supported by the Site-Directed Research and Development Program.


Cosmic Ray-Based Scanning: Techniques and Detectors Outline

• • • • • •

Overview Physics background Scanning modes My prior work at Los Alamos Applications, Commercialization & Interest Current NSTec progress on a solid-state system

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Objective

Use cosmic background radiation to inform some difficult scenarios: • Hidden and/or shielded SNM • Cargo scanning • Treaty verification • Spent fuel cask inspection

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Present & Past Collaborators National Security Technologies Dave Schwellenbach, Craig Krushwitz, Eugene Sheely, et al.

Fermi National Accelerator Lab Ron Lipton, Paul Rubinov, Bill Cooper, Mike Utes, Christinel Gingu, et al.

Sandia National Lab Nedra Bonal, et.al.

Los Alamos National Lab Chris Morris, Steve Greene, Richard Schirato, Bill Priedhorsky, Larry Schultz, Alex Klimenko, Gary Hogan, Kiwhan Chung, Jeff Bacon, Erica Sullivan, Wendi Dreesen, Derek Aberle, et al.

Decision Sciences Corp

Mike Sossong, Konstantin Borozdin, Mark Saltus, et al.

With Other Organizations

Gary Blanpied, John Perry, Michael Brockwell, Kolo Wamba, Sean McKenney

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Programmatic Background • Los Alamos National Laboratory - Proposed technology in 2001

• Decision Sciences International Corporation - Only commercializer of muon technologies, active since 2006. Funded LANL in CRADA 2006-2009 (approx.) - Successful Tech Transfer from LANL to DSIC

• National Security Technologies, LLC – Government applications since 2010

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• Tomography:

General Idea

•

Track individual muons (possible due to modest event rate).

•

Track muons into and out of an object volume.

•

Determine scattering angle of each muon.

•

Infer Z of material within volume

• Radiography: •

Make 2D shadow-graphs instead of 3D

•

Subtract baseline to get image


Cosmic Muons Radiograph the Pyramids 1970: Luis Alvarez was the first to use muons to view internal structures when looking for hidden chambers in the Giza pyramids using range muon radiography. …followed by many advances in Japan to study buildings, infrastructure, large artifacts, and volcanos led by Mintao, Nagamine, Tanaka, and many others


Some Physics

J. Andrew Green -8-


Cosmic Rays • Various nuclei from supernovae impinge on Earth atmosphere • From Hydrogen to Iron. • The very highest energies measured are in the 1011 GeV range – Kinetic energy of a baseball moving at 60 mph!

Particle Data Group, 2015 9


Cosmic Rays

• 10,000 /m2/min muons at sea level • ~Cos2(θ) distribution (θ from zenith) • ~4 GeV mean energy

Cosmic Rays at Earth, P.K.F. Grieder, 2001


The known elementary particles

Wikipedia: Elementary Particles

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The Incredible Cosmic Ray Muon Material Penetration of a MIP-ing muon → ~1800 g/cm2 → 2.6 meters of lead → 3.0 meters of iron → 18 meters of water

Effective lifetime: γτc = (38)(2.2µs)c = 25 km 3-4 GeV near minimum dE/dx of ~2 MeV/(g/cm2) Particle Data Group, 2006


Muon interaction – Multiple Coulomb Scattering

dN = dθ x

dN/dθ (arb)

θ0 =

13.5 pβ

−

e

θ x2 2θ 02

x

X

1.2 1 0.8 0.6 0.4 0.2 0

0

U Fe

-5

Source: Mike Sossong, DSIC

1 2π θ 0

0 θ (deg)

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How do we use the Physics?

J. Andrew Green -14-


Using Cosmic Muons for Imaging (Tomographic Mode) • • • • •

No Deflection

Med Z Moderate Deflection

High Z Large Deflection

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Quickest, best resolution imaging Track individual muons into and out of an object volume Calculate scattering angle of each muon Find location/size of objects Infer Z of material within volume


Transmission Mode Muon Imaging (or Radiography)

Incoming muon flux Flux attenuated by object

Higher density object

• • • •

Relies on attenuation of muons through materials Incoming cosmic-ray flux is constant Regions with greater density will show greater attenuation of the muon flux Useful for large structures, buildings, geologic structures, etc. 16


Stopped Track Mode • • • • • • •

Incoming Muon Track

Requires trackers on both sides of object Track all incoming muons Image using only incoming muons that have no outgoing muon Has potential when the stopped muon is important Low-Z materials Low energy muons Muon induced fission

Stopped track— No out-going muon detected 17

Vision – Service – Partnership


Correlated Mode – Couple Muon Tracking and Muon-Induced Fission Incoming muons slowed by scattering Muons (µ−) captured, creating muonic atom r ≈ r0 / 200 µ− captured by nucleus

External detector

A,Z → A,(Z-1) unstable to fission

Fission + keff → n, γ into 4π

Stopped track— No out-going muon detected 18

Incoming Muon Track


Prior Work at LANL



Large Muon Tracker at LANL 2004-2007 • 12’ x 12’ x 12’ • 896 channels • Drift gas: 60% Ar/ 40% Isobutane • ~200 Hz trigger rate at current geometry • 1.5 m tall sample area

Y

Z X

Sample Table


Building block: 2-inch Cylindrical Drift Tubes ∆T

µ

+

e-

Time of 1st hit on anode wire yields radius of closest approach!

Cylindrical Drift Tube Geometry • High E field very near 20 µm wire causes gas avalanche multiplication • Typical e- drift time ~1.5 µs on average •Spatial resolution goal ≤ 0.2 mm (based on toy drift tube measurements)

V

T0 Tmin Representative Anode Signal • Low count rate (~kHz) and multiplicity ⇒ Relatively large cell size allowed: D ~ 2 inch • Larger cell size ↔ fewer channels


Sand Barrel Scan

Tungsten Object

LANL

Tungsten cylinder and LANL letters in a 600 lb barrel of sand.


Engine Scan

Lead


Applications, Commercialization, and Interest



NSTec Work 2010-present • Focused on defining applications for government security applications since 2010 • SDRD (internally funded), NA-22 (DoE), Imaging of weapon trainers, neutron coincidence • Partnership with Sandia on tunnel scanning • Current SDRD project with Fermilab to produce solid state silicon-based trackers J. Andrew Green -25-


Tomographic Imaging of “Shield Box” • Imaged “Shield Box” from a few seconds to ~ 1 hour • Uranium can be hidden from conventional (n/gamma) monitoring

6 inches of polyethylene U

1 inch of Pb

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Shield Box Imaged in Tomographic Mode Poly

• Empty Box - Integration time 107 minutes Lead

Poly Lead

• Box with 20 kg LEU - Integration time 68 minutes LEU

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Shield Box Resolution Measurements - Setup • Image to test resolution capabilities in shielded configurations • Allows changing software parameters easily - Unclassified - No SNM

Shield box with ¼” Pb walls

1” diameter

Tungsten spheres inside box 28

2” diameter


Shield Box Resolution Measurements – Reconstructions • Wire mesh imaging showing top view and angled view • Z-slice image at approximate center of mass of spheres • 880 minutes integration time

Top view – wire mesh

Angle view – wire mesh

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Z-slice image


Geologic Imaging • • • •

Research in support of Sandia LDRD (Nedra Bonal). Muon imaging shows potential for geologic imaging Other researchers have done volcano imaging Our interest is in locating voids, tunnels, etc.

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Worldwide Interest • Conferences – IEEE-NSS dedicated muon session & numerous posters on passive muon scanning – SORMA West plenary talk(UK), NSTec poster in May 2016

• Countries showing interest – US, Japan, UK, Canada, Italy, Sweden, Russia, China

• Applications being explored – – – – – – –

Cargo scanning for Special Nuclear Materials Treaty verification Inspection/verification of nuclear fuel casks Mining industry, long-term underground monitoring Tunnel detection Volcano eruption prediction Fukushima reactor scanning (LANL, DSIC, Toshiba, TEPCO)

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Cargo Scanning

Upper tracker housing

Lower tracker below ground www.decisionsciences.com/mmpds

J. Andrew Green

• Multi-Mode Passive Detection System (MMPDS) • Testing of real cargo in the Bahamas • DHS-funded


Fukushima Daiichi reactor scanning

Used to measure possible melted-fuel location in Unit #2



Spent Fuel Cask Scanning Chalk River, Ontario

University of Glasgow

R. Al Jebali, et al., SORMA poster 2B-16 2016

Erlandson, et al., SORMA poster 2B-7 2016



Other works • Oregon State University – Scanning dry storage casks

• University of Sheffield, and UK Atomic Weapons Establishment (AWE). – Weapon’s-related

• Tsinghua University in Beijing – Energy measurement, material discrimination algos J. Andrew Green -35-


Current NSTec project – Silicon-based tracking



Drift-tube tracking issues • • • •

Bulky & massive detectors Restricted solid-angle Sealed or Flowing gas needed Anode wires accumulate debris filaments • Dead channels result in large acceptance gaps • 1-5ns clock synchronized to all front-ends needed for drift-radius

No Deflection

Med Z Moderate Deflection

High Z Large Deflection

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Silicon-based tracking Scope of Work: • Produce solid-state smaller, lighter, easierto-use tracker system. • Develop 1st concept for low-cost/area cosmic muon system. • Prototype & characterize. • Propose design of large-scale system.

Benefit: Treaty verification, homeland & nuclear security

Deliverable(s): • Produce proposed design of next-scale (~m2) system. • Prototype 1 ft2 tracker • Document concepts/techniques that could be used to reduce cost/area in near future.



How does silicon tracking work? • Strips along one dimension measure one coordinate; ~120 µm pitch • Orthogonal strips measure 2nd coordinate -> point of particle hit • Each strip is a reverse-biased diode, with ~300 µm depletion region • Depletion region is active. Charged particles leave energy: – 3 eV per electron-hole pair in Si – ~100 keV typical deposit for MIP – Good signal, resolution, timing • ASIC front-end ADCs get signal and serialize

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Advantage of thinner detectors in size, weight, and solid angle Solid angle for Silicon Strip case: 2.04 Sr. (~2.5 times larger track acceptance)

Solid angle for Drift-Tube case: 0.828 Sr.

L

L

h vs.

Solid angle computed relative to center

D

•

Additional Advantages

• • •

h D

Thickness (single-side nearly 4π (~3.5) in bi-directional horizontal mode) Lower power consumption and battery operation possible Low maintenance + “potting” to eliminate corrosion effects Tracking and calibration much simpler 40


Origin of the Technology: High-Energy Physics • Silicon microstrip detectors originally built for the compact muon solenoid (CMS) at LHC are being used. These are called CMS ST sensors. • Each sensor is a silicon wafer about 10 cm on a side and 0.5 mm thick. The microstrips are lithographed onto the wafer with 120-micron pitch.

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Collaboration with Fermilab in Batavia, IL • Fermilab is the flagship US lab for High-Energy (i.e. particle) Physics (HEP). Established late 60’s by Robert R. Wilson, a prominent physicist previously involved with the Manhattan project. • Accelerator-based particle physics at ever-increasing energies, from 400 GeV (early 1970’s) to present (2000 GeV) in fixed target and colliding beam programs. • Many particle discoveries & measurements done, accelerator technologies, detector technologies, and spin-offs developed there. • Driven by a need for high-resolution, low-mass detectors, FNAL established a major silicon-detector research & fabrication facility (Silicon Detector Facility, or SiDet) in late 1990’s. • Our SDRD is leveraging their expertise, facilities, and previously built prototypes to develop low cost/area detectors for cosmic muon tomography/radiography applications.

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Silicon Detector Facility (SiDet) at Fermilab (FNAL) • Built in late 1990’s • High-Energy, Astrophysics research support

• Constructed/Tested many designs and readout architectures • Clean rooms, fabrication & calibration equipment, personnel

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Sensor Mounting (one SKIROC mounted) HV filter board

Microstrips run this way CMS silicon microstrip sensor, ~10 cm on a side

Wire bonds

SKIROC ASIC (frontend readout/ADC)

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Sensor Layout for 1 ft2 Detector

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Mechanical Concept (carbon-fiber based)

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Sensor Readout

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Initial Readout Test

FMCIO Mezzanine card

• Met data acquisition firmware milestone • Good pedestal data from front-end chips (64 channels/chip)


Summary • Interest in passive scanning with cosmic muons has been steadily increasing since 1970, especially driven by computers & detector technology • NSTec is currently leveraging U.S. experimental high-energy particle physics investments to create Homeland Security applications • Working with Fermilab’s silicon detector expertise to build a prototype that will lead to larger-scale applications • Prototype design complete for 1 ft2 tabletop tracker • Next Steps for current SDRD project – – – – –

Complete a ft2 tracker Pursue improvements in performance, resolution, cost/area Perform portable demonstrations Pursing programmatic opportunities Publish results and pursue IP

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End



Mean scattering angle for a slice through the scene 50 cm above the base plate. The left panel shows the engine, the middle panel the engine plus the 10x10x10 cm3 lead sample, and the right panel the difference.


Previous Work – Tomographic Imaging • 8” diameter lead spherical shell - 1.3” walls - Approximately 5 kg DU inside

• Imaged in a few minutes using DSC’s large tracker - Minimal z-stretch with large detector

Pb sphere empty

Pb with DU

Courtesy of Decision Sciences

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Quick Detection, Less Detail, but SNM Detected • Empty Box - Integration time < 10 seconds Lead

Lead

• Box with 20 kg LEU - Integration time < 10 seconds LEU

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Shield Box Resolution Measurements – Reconstructions • 30 minutes of imaging 2 tungsten spheres with 1 cm voxels • Comparison of: - Top view – collapse entire image into one plane - Z-slice – show image at one z location Top view

Angle view z-slice & y-slice

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Frequency (arb)

25 Engine plus lead Engine

20 15 10 5 0 0

20

40

60

80

100

Maximum mean scattering angle (mrad) Histograms of the peak value of mean scattering angle, with a 10x10x10 cm3 average applied to the 2x2x2 cm3 voxels in a set of 40 4 minute reconstructions with the engine in the LMT.


ROC curves for identifying the lead object mounted in the LMT with the engine

1.2 1

Pdetection

0.8 0.6

240 sec 120 sec 60 sec

0.4 0.2 0 0

0.5

1 Pfalse positive

1.5


•

Requirements

High Energy Physics requirements for doing fundamental matter research based on 10 TeV proton-proton collisions: – High rate 25 ns bunch-crossing rate, ~20 proton-proton collisions/crossing  600 x 106 collisions/second to be processed! – Exquisite time resolution, pile-up resolution, signal-to-noise ratio – Very high radiation tolerance – Cooling to mitigate radiation damage – ~10 micron position resolution for track fits to find new decaying particles – Closed-in detector region for several years (no maintenance during the period)

•

Our needs, which include … – – – – –

Low occupancy (cosmic ray rates ~ 1 hit/cm2/sec) Some tolerance to radioactive sources Room temperature operation Compact, light, low-maintenance, easy to do tracking & calibration Less rigorous track resolution needed for cm-scale voxels

…will drive much lower sensor & electronics costs, while keeping the many advantages of solid-state operation, modularity & compactness!

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Muon Tracking to Detect Special Nuclear Materials

Shield Box Resolution Measurements – Reconstructions • Long integration time images in top view

Top view - 352 minutes

Top view - 880 minutes

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