M. Staib , M. Abercrombie, B. Benson, K. Gnanvo, M. Hohlmann
Michael Staib 1
description
Transcript of Michael Staib 1
Prototype of a Muon Tomography Station with GEM Detectors for Detection of Shielded Nuclear Contraband
Michael Staib1
V. Bhopatkar1, W. Bittner1, K. Gnanvo1,2, L. Grasso1, M. Hohlmann1, J. B. Locke1, J. Twigger1
1Dept. of Physics & Space Sciences, Florida Institute of Technology2 now at University of Virginia
2012 April APS Meeting, Atlanta, GA
Outline
• Concept of Muon Tomography and previous work.
• Prototype cubic-foot Muon Tomography Station (MTS) with GEM Detectors.
• The Gas Electron Multiplier (GEM) detector.
• DAQ electronics and analysis software.
• Experimental tomographic reconstructions of shielded and unshielded high-Z materials using this prototype.
Outline
Muon Tomography
Cubic-foot MTS with GEMs
Experimental Results
Future Work
Muon Tomography Concept Outline
Muon Tomography
Cubic-foot MTS with GEMs
Experimental Results
Future Work
μμ
Fe ULarge
ScatteringSmall
Scattering
μIron
Small Scattering
Uraniumμ
LargeScattering
μμIncoming muons (from natural cosmic rays)
Note: Angles Exaggerated!
)1( 1
with )]/ln(038.01[MeV6.13
00
0
0 ZZX
XxX
x
cp
Tracking detectors
Reconstruction AlgorithmPoint of Closest Approach
(POCA)
Object
Multiple Coulomb scattering to 1st order produces Gaussian distribution of scattering angles θ with width σ = Θ0:
Muon Tomography with Drift Tubes Outline
Muon Tomography
Cubic-foot MTS with GEMs
Experimental Results
Future Work
CMSCMS
Brass Cu
Pb W
Fe
Al
Original idea from Los Alamos (2003): Muon Tomography with Drift Tubes
Reconstruction of 1 inch thick Pb letters
J.A. Green, et al., “Optimizing the Tracking Efficiency for Cosmic Ray Muon Tomography”, LA-UR-06-8497, IEEE NSS 2006.
INFN : Muon Tomography with spare CMS Muon Barrel Chambers (Drift Tubes)
S. Presente, et al., Nucl. Inst. and Meth. A 604 (2009) 738-746.
1.4 m1.4 m4.3 m4.3 m
1122
33
Decision Sciences Int’l Corp.: Multi-Mode Passive Detection System, MMPDSTM
from Decision Sciences public web pages
INFN
Compact Cubic-Foot Muon Tomography Station Using GEMs
Outline
Muon Tomography
Cubic-foot MTS with GEMs
Experimental Results
Future Work
Plastic Scintillator (Trigger)
Triple-GEM Detector1 ft3
active
volume
30 cm
Gas Electron Multiplier (GEM) Detector
V
μ-
e-
GEM foil under electron microscope
~400 V
Gas Gain ~ O(104)M.C Altunbas, et al., Nucl. Inst. and Meth. A 515 (2003) 249-254.F. Sauli, Nucl. Inst. and Meth. A 386 (1997) 531-534.
Outline
Muon Tomography
Cubic-foot MTS with GEMs
Experimental Results
Future Work
• 30 cm x 30 cm triple-GEM detectors
• Follows design for COMPASS at CERN
• Ar/CO2 70:30 mixture
• X-Y Cartesian readout @ 400 μm pitch
• ~50 µm spatial resolution for perpendicular tracks
• Compact detector, low material budget
Triple-GEM Detector for MT station
COMPASS Design
Assembled GEM Detector
Drift Cathode
GEM foil
FR4 Spacer Frame
X-Y Readout
Nucl. Inst. and Meth. A 490 (2002) 177–203
Insulating Layer Readout Strips(top layer)
Support
Readout Strips(bottom layer)
400 μm
400 μm
340 μm
80 μm
Outline
Muon Tomography
Cubic-foot MTS with GEMs
Experimental Results
Future Work
DAQ Electronics
• Scalable Readout System (SRS) developed by the RD51 collaboration at CERN.• Currently 11 teams using SRS for different applications using MPGDs.• Florida Tech is currently the largest user with ~12k channels of analog readout.
Outline
Muon Tomography
Cubic-foot MTS with GEMs
Experimental Results
Future Work
HDMIGb Ethernet
APV25 HybridADC FEC
• 128 channel APV25 chip• 192-deep analog sampling memory• Master/slave configuration• Diode protection against discharge• RD51 standard 130-pin Panasonic
connector interfaces to detector• HDMI mini (type C) connector
• 2 x 12-Bit Octal ADC• 8 x HDMI input channels (16 APV hybrids)
• Virtex LX50T FPGA• SFP/Gb Ethernet/DTC interface• NIM/LVDS GPIO (trigger, clock synch, etc.)
DAQ Computer
• Data Acquisition using DATE (ALICE @ CERN)
• Support added for data transfer via UDP • Slow control via ethernet• Online and offline analysis using custom
package for AMORE (ALICE @ CERN)
Detector Characterization using AMORE
Note: Crossed structure due to spacer frames
Charge Sharing2D Hit Map
Cluster SizeCluster Multiplicity Cluster Charge Distribution
Signal to Noise Ratio
Mean = 1.2 Clusters Mean = 4.7 Strips
Material Discrimination: Scenario
LeadZ = 82
Density = 11.3 g/cm3Depleted Uranium
Z = 92Density = 19.1 g/cm3
TungstenZ = 74
Density = 19.3 g/cm3
TinZ = 50
Density = 5.8 g/cm3
IronZ = 26
Density = 7.9 g/cm3
Outline
Muon Tomography
Cubic-foot MTS with GEMs
Experimental Results
Future Work
6mm Al shielding
Simple Scattering Density (Degrees / cm3)
Uranium Tungsten Lead Tin Iron
157.8 115.3 101.0 68.9 61.3
Material Discrimination: Result
-55 mm < z < -15 mmMin. # of muon per voxel = 2
Outline
Muon Tomography
Cubic-foot MTS with GEMs
Experimental Results
Future Work
Lead Tungsten
IronTinUranium
155,104 Reconstructed Tracks
Voxel Size: 2 x 2 x 40 mm3
Material Discrimination: ResultXZ Slices
YZ Slices
Sn
+X
+YFe
Fe
U
U
Sn
Sn Pb W
WPb
Pb W
Fe
-70 mm < Y < -30 mm -20 mm < Y < 20 mm 30 mm < Y < 70 mm
30 mm < X < 70 mm-20 mm < X < 20 mm-70 mm < X < -30 mm
155,104 Reconstructed Tracks
Uranium with Brass Shielding
The shielded uranium block can clearly be seen in the reconstruction
Outline
Muon Tomography
Cubic-foot MTS with GEMs
Experimental Results
Future Work
40 mm XY slices with Z decreasing by 5mm each frame 187,731 Reconstructed Tracks
Future Work Outline
Muon Tomography
Cubic-foot MTS with GEMs
Experimental Results
Future Work
• Increase the number of GEM detectors per tracking module to improve reconstruction.
• Redesign support structure to allow more freedom in detector orientation.
• Implement statistical reconstruction methods and POCA clustering algorithms.
• Improve tracking and sensor alignment methods in the AMORE analysis package.
• Include a measurement of muon momentum in the reconstruction.
• Scale up! (Next goal is ~1 m3 active volume)
Thanks!Questions?
Disclaimer: This material is based upon work supported in part by the U.S. Department of Homeland Security under Grant Award Number 2007-DN-077-ER0006-02. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security.
Backup Slides
0 mm 2 mm 4 mm
6 mm 8 mm
Image Resolution Study: Imaging a gap separating W and Pb blocks
115,834 muons 94,719 muons 111,036 muons
107,506 muons 121,634 muons
0 mm 2 mm 4 mm
6 mm 8 mm
Scattering Density (deg/cm3)
Statistically significant signal with 8mm spacing Analysis Region