T' W' Leadbeater, D'J' Parker, X' Fan, A' Ingram

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Positron Imaging at Birmingham
T. W. Leadbeater, D.J. Parker, X. Fan, A.
Ingram Positron Imaging Centre. IoP Birmingham
2009
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Positron Imaging
Positrons produced from b decay of proton rich
nuclei Positron loses energy
annihilates Results in 2 back-to-back 511 keV
photons Coincident detection of both
photons defines trajectory Medical imaging
involves radio-labelling of glucose
molecules Industrial imaging involves labelling
fluids or particles
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Positron Emission Tomography
Acquisition times Minutes hours 109 events
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Industrial Imaging
Broad range of multi-phase flow processes used
in industry Solid particles, bubbles, liquid
drops Particulate flow is poorly
understood Granular materials behave as
materials in different phases depending upon
conditions e.g. Quicksand, vat of custard,
water cornflour
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Positron Emission Particle Tracking
Single particle loaded with radioisotope Line
of Response (LOR) defined along photon
trajectory Triangulation of successive LORs
gives particle location 50 of 511 keV photons
are transmitted through 11 mm steel
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Start with initial number of events N
Calculate minimum distance point
Remove furthest trajectories
Iterate over N
Stop when fraction f remains
MDP is tracer particle location
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Detector Systems
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New Data Acquisition System
Performance is limited by the original data
acquisition system Max data rate 1MHz
Time resolution adjustable to event rate.
Currently set to be 2 kHz (0.5 ms period)
Sustained data rates 120 kHz (moving
tracer) 3.8 MHz (stationary tracer) 16
Mbytes per second disk transfer (3 Gb in 188
s) Locations on average 11.3 ms using 2000 events
/ location
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Fluidised bed Chemical Engineering
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Plastic Extrusion IRC Birmingham
These results are to be published shortly.
Information can be found at http//www.peptflow.c
om/
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Practical Demonstration
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Results
75 kBq source 2.5 kHz event rate 140 ms per
location 1.35 mm precision
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Results
Motion directed forward and to the left
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Results
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Results
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Results
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Realistically
Activity lt 100 MBq Tracers with a size range 50
mm mms Range of materials Glass, resins,
Catalysts, FCC and Gamma alumina, drugs, plant
seeds, potatoes, salt
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Conclusions
A modular positron camera has been developed
allowing the study of a wide range of industrial
systems The flexible geometry offered by the
modular camera allows Advantages of modern
systems to be utilised The field of view of the
camera to be custom designed Transportation of
the camera to study applications in situ. New
camera systems used for a number of successful
experiments Various locations both on and off
campus Recorded data at rates up to 4 MHz
(factor of 40 improvement) Frequent and accurate
locations
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Thanks Questions ?
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Positron Emission Particle Tracking
N Initial number of events Generally between 50
and 500 events per location Decreased for fast
moving particles f Fraction of N in final
solution Dependent upon scattered and corrupt
events Determined experimentally d Standard
deviation of final trajectories Quantifies
relative accuracy of locations
D.J. Parker et. al., Nucl. Inst. Meth., A326
1993
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Fluidised bed BP, Hull UK
Portable positron emission particle tracking for
industrial use, A. Ingram et. al. 12th
international conference on fluidization , 2007