Post on 07-Apr-2022
120th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Energy-resolved neutron imagingwith MCP/Medipx technology
Energy-resolved neutron imagingwith MCP/Medipx technology
A.S. Tremsin , J.V. Vallerga
Space Sciences LaboratoryUniversity of California at Berkeley, USA
220th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
14 mm
Unique capabilities of neutron imaging
320th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
X-rays versus neutrons
X-rays interact with electrons in the atoms.The heavier is the atom – the larger is absorption of X-rays.
Neutrons interact with nucleus and have very different absorption contrast.
NIST annual report 2003, D. Jacobson, M. Arif, and P. HuffmanPhysics Laboratory Ionizing Radiation Division
420th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
14 mm
New detector technology we use in neutron imaging was partially
developed for astrophysical applications:
• Event counting• UV, soft X-ray sensitive• High dynamic range• Low noise/background• Good spatial resolution
520th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Detectors developed at Berkeley for NASA applications
MCP detector technology developed for astrophysical
applications
NASA Image satellite
620th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
14 mm
Mdipix/Timepix neutron imaging was pioneered byInstitute of Experimental and Applied Physics,
Czech Technical University in Prague
720th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
MCP electron amplifier for UV/neutron detection
Circular pores ~8 m
V1
V2
Single pore
1 mm absorption
length
Walls between pores ~2 m
10B and Gddoping in glass
n
7Li
4He
1 mm absorption length~2 m escape range
High detection efficiency
820th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
64 data lines@100 MHz
MCPs
Timepixreadout
FPGA
64 data lines@100 MHz
FPGA
PCPC10 Gb interface10 Gb interface
~1.8 Mb/frame, up to 1200 frames/s
~1.8 Mb/frame, up to 1200 frames/s
Up to ~6 Gb/s
Vacuum ~10-6
Torr
• Bright pulsed neutron beams
• New neutron counting detectors with high timing and spatial resolution @ high count rates
Enabling technology: MCP/Timepix detectors
Active area with 2x2 Timepixchips (28x28 mm2)
Fast parallel readout (x32) allowing ~1200 frames per second and ~300 s dead time
Wide transmission spectrum measured at the same time.
A.S. Tremsin, et al., NIM A 787 (2015) 20–25.
920th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Neutron cross sections vs. energyThermal range
1-5 Å (~4-100meV)
Bragg edges
Epithermal range1eV-10 keV (~2-300 mÅ)
Resonance attenuation
Crystallographic parameters extractedPhase
Texture Lattice parameter
Elemental/isotopic compositionTemperature map
1.0E+01
1.0E+02
1.0E+03
1.0E+04
1 10 100C
ross
sec
tion
(bar
ns)
Neutron energy (eV)
Eu-153
1020th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
From radiography to energy resolved imaging
Images are taken from google images website
1120th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
All energies are imagedat the same time!
Propagating neutron pulse
Neutron counting2D detector
Time
X
Y
Trigger synchronized to the source
X,Y,T for every detected neutron
Pulsed Neutron Source20 - 60 Hz
~100 ns pulses
Sample
~250,000 spectra is measured simultaneously!
Energy-resolved neutron imaging: time of flight
0.30.350.4
0.450.5
0.550.6
0.65
1 2 3 4 5
Tran
smis
sion
Wavelength (Å)
N2N1Annealed
200311 220 111
1220th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Application examples.
Optimization of crystal growth: In-situ imaging
1320th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Slide by Prof. J.J Derby, Univ. Minnesota
1420th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Industrial Bridgman furnace: RMD
A two-zone furnace, which allows 2” growth. Theoretically it can be used in neutron imaging experiments,
although our 5-zone furnace is better suited for it.Proc. of SPIE Vol. 8507 850716-1,
Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XIV
1520th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Understand and optimize growth process for single crystal materials.
Transfer that knowledge to industrial scale production.
Crystal growth: In-situ measurement
Dedicated furnaces optimized for neutron imaging were developed.
1620th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Experimental setup pulsed beam: energy resoled imaging
Map of Euconcentration
~250000 spectra are measured
at the same time, each within 55 um pixel!
A.S. Tremsin, et al., Scientific Reports 7 (2017) 46275
1720th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019Jeff Derby, Univ. Minnesota
1820th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Crystal growth – in situ diagnosticsInitially 1 mm/hr pull speed. Increased to 2 mm/hr. Strong asymmetry of interface seen at high speed.
20 min image acquisition per step
1. Interface is convex, as desired.2. Interface remains at the same position/moves slowly during regular growth.
Should allow real-time adjustment of T profile to keep the interface convex and at the desired location.
1920th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Controlled interface shape
Sample width ~11 mm
Interface between the liquidand solid phases is convex.Contrast is due to segregation of Eu (CsI:Eu)and Li (in TLYC) between the liquid and solidphases.
Booster heater area. Neutron scattering distorts the image.
(CsI:0.5%Eu)Tl2LiYCl6:Ce
2020th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
In-situ Eu distribution quantification
00.10.20.30.40.50.60.70.80.91
0.01 0.1 1 10
Tran
smission
Neutron enery (eV)
Solid 5% Solid 0.5% Melt 5%Theory 5.5% Theory 0.4% Theory 4%
Eu concentration (mole %)
00.10.20.30.40.50.60.70.80.91
0 5 10 15 20
Eu con
centratio
n (m
ole %)
Position (mm)
0.5% Eu
Started growth
Solid/liquid interface
0123456789
10
0 5 10 15 20
Eu con
centratio
n (m
ole %)
Position (mm)
5% EuStarted growth
Solid/liquid interface 0
123456789
10
0 2 4 6 8 10 12Eu
con
centratio
n (m
ole %)
Position (mm)
Solid phaseLiquid phase
5 mole % Eu doping
Vertical profiles
Radial profiles
Scientific Reports 7 (2017) 46275
2120th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
In-situ measurement of strain
2220th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Load in Spiralock threads: vibrational stability
Steel screws in Al base
Steel screws in stainless steel
A.S. Tremsin, et al., Strain 52 (2016) 548-558
2320th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Torqued to 185 lb-in Not torqued
-1000
-800
-600
-400
-200
0
200
400
0 5 10 15 20 25 30
Mic
rost
rain
µε
Distance Along Bolt mm
RegularSpiralock
Thread start
Loaded Steel
-1000
-800
-600
-400
-200
0
200
400
0 5 10 15 20 25 30
Mic
rost
rain
µε
Distance Along Bolt mm
RegularSpiralock
Thread start
Unloaded Steel
A.S. Tremsin, et al., Strain 52 (2016) 548-558
Load in Spiralock threads: vibrational stability
2420th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Larger contiguous MxN area (TSVs)Better timing resolution Huge dynamic rangePhoton/particle counting
Future capabilities enabled by Timepix4
28x28 mm (2x2 Timepix)
200x200 mm (7x7 Timepix4)
Hubble Space
Telescope2.4 m(1990)
James WebbSpace
Telescope6.5 m
(~2021)
LUVOIR 16 m!!(~2035)
2520th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
CERN Medipix teamAdvacamNIKHEF, Amsterdam IEAP, PragueUniversity of California at Berkeley, CA, USA
A.S. Tremsin, J. B. McPhate, J. V. Vallerga, O. H. W. SiegmundNova Scientific, Inc, Sturbridge, USA (manufacturer of neutron sensitive MCPs)
W. B. Feller, P. White, B. WhiteRutherford Appleton Laboratory, ISIS Facility, UK
W. Kockelmann, J. Kelleher, S. Kabra, D.E. Pooley, G. Burca, T. Minniti, E. Schooneveld, N. RhodesJ-PARC Center, JAEA, Nagoya University, Japan
Y. Kiyanagi, T. Shinohara. T. Kai, K. OikawaLANSCE, Los Alamos National Laboratory Lawrence Berkeley Laboratory
S. Vogel, A. Losko, M. Mocko, M.A.M. Bourke, R. Nelson D. Perrodin, G.A. Bizarri, E.D. BourretPaul Scherrer Institute, Switzerland
E. Lehmann, A. Kaestner, T. Panzner, P. Trtik, M. ManganoIstituto dei Sistemi Complessi, Sesto Fiorentino (FI), Italy European Spallation Source Scandinavia
F. Grazzi M. Strobl, R. WoracekANSTO Technical University of Denmark
A. Sokolova, A. Paradowska, V. Luzin, F. Salvemini S. SchmidtCONICET and Instituto Balseiro, Centro Atomico Bariloche, Argentina
J. SantistebanSpallation Neutron Source, Oak Ridge National Laboratory, USA Open University, Coventry University, UK
H. Z. Bilheux, L.J. Santodonato M. Fitzpatrick, R. RamadhanTechnische Universität München, Forschungs-Neutronenquelle FRM-II, Germany
B. Schillinger, M. LercheDepartment of Geology and Environmental Earth Science, Miami University
John RakovanWelding Science, Cranfield University General Electric Global Research
Supriyo Ganguly Yan GaoUniversity of Newcastle, Latrobe University, Australia
C. Wensrich, E. Kisi. H. Kirkwood
The work done in collaboration
…and many others!apologies for missed names
2620th Anniversary symposium on Medipix and Timepix, CERN, September 18, 2019
Thank you for your attention! This work was done within the Medipix collaboration.
We would like to thank Medipix collaboration for the readout electronics and data acquisition software (Advacam, Prague and Espoo, NIKHEF, Amsterdam and IEAP, Prague).
This work was supported in part by U.S. agencies: NASA, DOE, NSF, NIH and NNSA.