Technology Demonstration Workshop on Gamma Imaging

IAEA Headquarters, Vienna and IAEA Laboratories, Seibersdorf

19-23 October 2015

Preliminary External Technical Report

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Table of Contents

1. Summary, Purpose and Scope ........................................................................................................... 3

2. Workshop overview, conclusions, and follow-up actions ............................................................... 32.1  Overview ...................................................................................................................................... 3 2.2  Details of the work performed ...................................................................................................... 5 

3. Preliminary technical result analysis ................................................................................................ 63.1  Experiment 1: efficiency measurement ....................................................................................... 6 3.2  Experiment 2: overnight identification and false alarm rate ........................................................ 7 3.3  Experiment 3: sensitivity .............................................................................................................. 7 3.4  Experiment 4/5: angular resolution .............................................................................................. 8 3.6  Experiment 6: extended sources ................................................................................................. 8 3.7  Experiment 7: high background ................................................................................................. 10 3.8  Experiment 8: angular resolution for extended sources ............................................................ 10 

4. Conclusion and follow-up actions ................................................................................................... 11

5. Abbreviations and glossary .............................................................................................................. 11

6. Annexes .............................................................................................................................................. 11

A.  Technology demonstration workshop agenda, list of participants and observers .................... 12 A.1  Agenda ...................................................................................................................................... 12 A.2  List of participants: ..................................................................................................................... 13 A.3  List of observers: ....................................................................................................................... 13 

B.  Technical characteristics of the participating systems ................................................................. 14 

C.  Experiment protocol .......................................................................................................................... 16 

D.  Experiment setup ............................................................................................................................... 20 

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1. Summary, Purpose and ScopeA Technology Demonstration Workshop on Gamma Imaging was held at IAEA HQ and Seibersdorf Laboratories on 19-23 October 2015. The technologies demonstrated comprised CZT/CdTe detectors, a LaBr3-detector and HPGe detectors. Capabilities of 8 devices over a set of experiments relevant to IAEA applications were demonstrated. This document provides an overview of the Technology Demonstration Workshop (TDW) and a preliminary technical assessment of the different technical characteristics and performance of the demonstrated gamma imaging systems (emerging prototypes and commercial off-the-shell) in application to IAEA safeguards’ needs.

2. Workshop overview, conclusions, and follow-up actions

2.1 Overview

A TDW on Gamma Imaging was held at IAEA HQ and Seibersdorf Laboratories on 19-23 October 2015. The technologies demonstrated comprised CZT/CdTe detectors, a LaBr3-detector and HPGe detectors. The capabilities of 8 devices over a set of experiments relevant to IAEA applications were demonstrated.

The workshop started on 19 October by introductory presentations regarding workshop objectives (S. Zykov, IAEA), safeguards overview (D. Finker, IAEA), and an overview of the procurement process (A. Ivanov, IAEA). These were followed by the participants’ presentations of technologies and instruments brought to the TDW. The technologies and instruments demonstrated included:

CZT/CdTe detectors

Polaris-H 3-dimensional position-sensitive CdZnTe gamma-ray

imaging spectrometer (H3D / University of Michigan, USA)

High-Efficiency Multi-mode Imager HEMI Lab Prototype (LBNL, USA)

Canberra iPix Platform (Canberra, USA)

CEA HiSpect Camera (CEA, France)

Createc Mobile 3D prototype (Createc, UK)LaBr3 detector RadSearch Model G-3050 Gamma Camera (ANTECH, UK)

HPGe detectors two GeGI Gamma-ray Imaging (PHDS Co, USA)

ORNL HPGe Gamma-ray Imager (ORNL, USA)

On 20-23 October, the imagers were tested at the IAEA Laboratories in Seibersdorf, Austria. A special test location was set up for this purpose at the Safeguards Instrumentation Laboratory (SIL). The test location accommodated a camera rack, a nuclear material stand with target screen and optional shielding, and a few tables to host cameras’ control systems and other equipment. Most of the gamma cameras were positioned on the shared rack equidistantly from the target sources and pointed towards them; due to specific requirements, two cameras (RadSearch Model G-3050 Gamma Camera and ORNL HPGe Gamma-ray Imager) were positioned on tripods close to the rack. All systems were set in far-field condition.

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Figure 1 Experiment setup scheme and 3D scanned images

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Figure 2 Images of the camera rack (on the left), the camera rack with all cameras installed (in the centre), and

the target screen (on the right) hiding the sources and holding a grid, a sync-up clock, and

experiment/measurement number notes.

During the tests, the instruments were operated by respective team staff under the presence of IAEA

organizing staff and observers. The tests were organized according to the following sequence: Tests aimed to assess general gamma imagers’ characteristics including efficiency,

sensitivity, angular field of view, and angular resolution.

Tests imitating and/or related to possible safeguards applications including scenarios with

extended sources and a glovebox scenario.

The following radioactive nuclear materials were used during experiments:

Table 1 Source library used during the workshop

Isotope Peaks, keV241Am 59.6137Cs 66260Co 1333LBU Pu 129 + 413 HBU Pu 148 + 208 LEU 186 + 1001 HEU 186MTR plate 186 + 1001

The experiment notes and measurements taken were recorded in measurement protocols by participants and observers. Results of all tests were copied to USB flash drives and provided to the organisers at the end of the workshop; the data were also kept by participating teams in order to allow further post-processing and more comprehensive evaluation by IAEA. After the workshop, the IAEA sent to all participants a small form to be filled in in accordance with preliminary results obtained. An evaluation of gamma imagers based on this form is provided in the next sections of the current document. Complementary observations made by observers are also shown in the following parts.

2.2 Details of the work performed

The workshop agenda and list of participants are presented in Annex A. Some technical characteristics and images of the instruments are shown in Annex B. The test protocol and the experiment setup are shown in the Annex C and D.

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3. Preliminary technical result analysisThis chapter is based on straightforward comparison of the first processing of results performed by the participants and submitted to the IAEA in similar spreadsheet forms under the same template. A more comprehensive evaluation (currently on-going with the support of EC JRC) will be established in the final report, and will take into account additional criteria such as:

Spectrometric and imaging performance

Compatibility with the Contextual Usage Scenarios(CUS)

User interface Interface usability Features of the processing software Visual representation of data

Operation

Dimensions Weight (collimator, battery) Battery operation (battery life, type) Ruggedness, environment (operating temp, IP rating) Time to operation (from shipping to full operation)

Technology

Detector type Detector dimensions and volume Number of pixels Technologies

Additional experiments with real glove boxes have been conducted, but are not commented in the current report.

3.1 Experiment 1: efficiency measurement

Table 2 Efficiency (in kc/nSv) in different measurements

Camera Cs137,

0.5 mCi at 3m Am-Li,

1 Ci at 5m Co 60,

65 MBq at 5m 1 0.1 2.3 0.012 Did not participate Did not participate Did not participate 3 0.5 2.7 N/A4 0.03 1.5 0.0075 0.002 0.37 0.00046 0.5 9.6 0.057 Did not participate Did not participate Did not participate 8 No results provided No results provided No results provided

Remarks:

Two gamma cameras (2, 7) have not participated in the experiment due to organizational ortechnical issues.

The results from the gamma camera 8 have not been provided at the time of writing of theversion 1 of the current report due to the long time necessary to process the data. Onceprovided, these results will be included in the final report.

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3.2 Experiment 2: overnight identification and false alarm rate

Table 3 Sources identified during overnight measurement with repetitive hourly acquisitions

Camera Detected Identified Localized 1 Yes Yes, Cs137 Yes2 Did not participate Did not participate Did not participate 3 Yes Yes, Cs137 Yes4 Yes Yes, Cs137 Yes*5 Did not participate Did not participate Did not participate 6 Yes Yes, Cs137 Yes7 Did not participate Did not participate Did not participate 8 No data No data No data

Remarks: * The sources were not localized in hourly acquisitions, but localized after processing the data

cumulated in the overnight measurement. Three gamma cameras (2, 5, 7) have not participated in the experiment due to the

organizational and technical issues. The results from the gamma camera 8 have not been provided at the time of writing of the

version 1 of the current report due to the long time necessary to process the data. Onceprovided, these results will be included in the final report.

3.3 Experiment 3: sensitivity

Table 4 Time to detect / to identify / to localize the source (in seconds)

Camera HBU Pu LBU Pu 2x LEU

extended sources

LEU extended

source

2x LEU HBU Pu LBU Pu

LEU (MTR)

1 15 30 45 45 70 452 NA NA NA NA NA NA3 12/54/60 NA/300/273 7/7/30 14 / 37/ 46 8 / 8/ 22 15/20/32 4 140/252/NA NA 12/12/NA 52/52/NA 72/468/NA 18/18/NA 5 NA/429/NA NA/183/NA NA/387/NA NA/369/NA NA NA 6 3 / 3 / 38 48 / 48 / 290 0.1/0.1/7 0.5/0.5/25 1/1/12 NA 7 6 86 47 48 20 5518 No data No data No data No data No data No data

Remarks: Due to software implementation, the benchmark of times to detect/identify/localize is not

suitable for the camera 1. Time for single acquisition is given instead. The camera 2 was not able to localize the sources due to the short acquisition times; nor

could it identify the sources due to technical limitations. Due to limitation in the camera 7 software, it is not possible to separate times to

detect/identify/localize the sources; 90% of time to alarm (defined by proprietary specificalgorithm) is given instead.

The results from the gamma camera 8 have not been provided at the time of writing of theversion 1 of the current report due to the long time necessary to process the data. Onceprovided, these results will be included in the final report.

This experiment was repeated several times, to cover various zones of the field of view of thesystem. No significant variations of the sensitivity throughout the field of view were observed.

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3.4 Experiment 4/5: angular resolution

Table 5 Angular resolution measured as a minimal angle at which the system is still capable of separating two point Am-Li sources and two point Co60 and Cs137 sources

Camera Measured angular

resolution 2x Am-Li Measured angular resolution Co/Cs

1 4° 6°2 7° >6°3 3° 3° 4 NA 3°* 5 No data No data 6 5° 5° 7 3° 3° 8 No data No data

Remarks: * When processing the experiment results, the camera 4 team filtered energy spectra to

resolve Co60 and Cs137 sources independently and therefore localize them accurately. Results would be different with two sources of the same energy.

The results from two gamma cameras (5, 8) have not been provided at the time of writing ofthe version 1 of the current report due to the long time necessary to process the data. Once provided, these results will be included in the final report.

This experiment was repeated several times, using several isotopes, to cover various zonesof the field of view of the system; no significant variations of the angular resolution were observed.

3.6 Experiment 6: extended sources

Table 6 Capability to identify the geometry of extended sources and localize supplementary weak point sources

Camera Geometry identified Point sources localizes 1 Area is correctly defined, missing part is visible, detailed

geometry is not clear No

2 Only the source area is identified No 3 Area is correctly defined, detailed geometry is partly visible,

missing part is not localized Few Cs137 sources localized

4 U source is not detected

Cs137 and Co60 sources localized

5 No data No data 6 Area is correctly defined, missing part is localized, detailed

geometry is partly visible Identified, but not localized

6 U source is identified but not localized Cs137 and Co60 localized 7 Area is correctly defined, missing part is localized, detailed

geometry is visible Cs137 and Co60 localized

8 No data No data

Remark: The camera 6 has performed the measurements in two separate configurations resulting in

different performance; both results are provided. The results from two gamma cameras (5, 8) have not been provided at the time of writing of

the version 1 of the current report due to the long time necessary to process the data. Once provided, these results will be included in the final report.

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Figure 3 False-color gamma images overlay of the extended LEU and point sources obtained by different cameras

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3.7 Experiment 7: high background

The goal of the experiment was to estimate the capabilities to identify/localize the weak sources in non-uniform high background conditions. Several relatively strong point sources were positioned in the test room outside the centre of view of the cameras and producing 4 uSv/h dose rate at the target screen. Much weaker (net dose rate around 500 nSv/h) point sources were positioned in the centre of the field of view of the cameras producing only a marginal increase of the total dose rate induced from the stronger background sources.

Table 7 Capability to identify/localize target sources in presence of high background or next to a much more intense point source within the field of view.

Camera Target sources identified/localized 1 Pu, Co, and Am identified, but poorly localized (only the strongest source is properly

localized at the time). 2 No identification possible. Only the strongest source is localized. 3 Pu, Am, and Co60 are identified. Only the 1-2 strongest sources are localized. 4 Am and Co are identified but not localized. The camera performs better when moved

close to the target. 5 No data 6 Pu, Co, and Am identified, but poorly localized (only the strongest source is properly

localized at the time). 7 Pu, Co, and Am identified, but poorly localized (only the strongest source is properly

localized at the time). 8 No data

Remark: The results from the gamma camera 8 have not been provided at the time of writing of the version 1 of the current report due to the long time necessary to process the data. Once provided, these results will be included in the final report.

3.8 Experiment 8: angular resolution for extended sources

Table 8 Capability to reconstruct geometry of two separated sources

Camera 2 extended U sources

separated at: 2 point Pu sources of different activity

separated at: 3° 5° 4° 8°

1 No Yes No Yes 4 N/A N/A No No 6 No No No No 7 Yes Yes Yes Yes 8 No data No data No data No data

Remarks:

The other systems participated in the glove box scenario instead of this experiment. Its analysis will be documented in the final workshop report.

The results from the gamma camera 8 have not been provided at the time of writing of the version 1 of the current report due to the long time necessary to process the data. Once provided, these results will be included in the final report.

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4. Conclusion and follow-up actions The Technology Demonstration Workshop provided a useful overview of the capabilities of modern gamma-imaging systems including both commercially available products and emerging prototypes. The main preliminary conclusion is that currently there is no one single best available gamma camera that could fit all possible SG applications; however certain cameras may fit specific scenarios. Determining which cameras fit which scenario will be the main objective of the final report. The mobile technology for 3D scene reconstruction and gamma-image overlaying is promising, but due to its current prototype stage, some developments are needed before these systems can be deployed during field activities. Detailed results of the workshop and the estimated match of different gamma imagers to identified SG usage scenarios will be summarized in the final report expected from EC JRC in Q1 2016.

5. Abbreviations and glossary TDW – Technology Demonstration Workshop CUS – Contextual Usage Scenario LEU – Low-Enriched Uranium HEU – High-Enriched Uranium LBU Pu – Low-Burnup Plutonium HBU Pu – High Burnup Plutonium

6. Annexes Annex A: Technology demonstration workshop agenda and list of participants Annex B: Technical characteristics of the participating systems Annex C: Experiment protocol Annex D: Experiment setup

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A. Technology demonstration workshop agenda, list of participants and observers

A.1 Agenda Monday 19 October – Room M7 9:00 Opening comments by SGTS-DIR 9:15 Workshop objectives (D. Finker) 9:40 Procurement perspectives (A. Ivanov) 10:05 Presentation ANTECH: RadSearch Model G-3050 Gamma Camera (Mr. John A. Mason) 10:40 Coffee Break 11:10 Presentation Canberra: iPix Platform

(Messrs. Nicolas Humbert, Durim Kryeziu & Martin Rushby) 11:45 Presentation CEA: HiSpect Camera

(Messrs. Olivier Monnet & Guillaume Montemont) 12:20 Lunch 13:20 Presentation Createc: Gamma Imaging System

(Messrs. Neil Owen & Alan Shippen) 13:55 Presentation H3D/University of Michigan: Polaris-H 3 (Messrs. Zhong He, Willy Kaye & Thomas McKnight) 14:30 Coffee Break 15:00 Presentation LBNL: High-Efficiency Multi-mode Imager (Messrs. Ross Barnowski & Kai Vetter) 15:35 Presentation ORNL: HPGe Gamma-ray Imager (Mr Klaus Ziock) 16:10 Presentation PHDS Co.: GeGI Gamma-ray Imaging (Messrs. Ethan Hull & Desmond Longford) 16:45 Time buffer - Discussions 17:15 Reception – VIC Cafeteria Salon A (max. until 19:15) Tuesday 20 October 8:00 Departure from VIC to Seibersdorf Laboratories 9:15 Equipment setup 12:15 Lunch 13:00 Start of experiments 16:00 Departure to VIC Wednesday 21 October – Thursday 22 October 8:00 Departure from VIC to Seibersdorf Laboratories 9:15 Experiments 12:15 Lunch 13:00 Experiments 16:00 Departure to VIC Friday 23 October 8:00 Departure from VIC to Seibersdorf Laboratories 9:15 Experiments/packing 12:15 Lunch 13:00 Packing of equipment 14:30 Departure to VIC

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A.2 List of participants:

Company Representative Contact data

ANTECH John Mason +44 (0) 1491 824444 mason.john@antech-inc.com

Canberra Nicolas Humbert Martin Rushby Durim Kryeziu

+33 (1) 39 48 51 08 nicolas.humbert@canberra.com martin.rushby@canberra.com d.kryeziu@cpce.net

CEA Olivier Monnet Guillaume Montemont

olivier.monnet@cea.fr guillaume.montemont@cea.fr

Createc Neil Owen Alan Shippen

neil.owen@createc.co.uk alan.shippen@createc.co.uk

H3D Zhong He Willy Kaye

+1-734-764-7130 hezhong@umich.edu willy@h3dgamma.com

Lawrence Berkeley National Laboratory

Ross Barnowski Kai Vetter

kvetter@lbl.gov kvetter@berkeley.edu

Oak Ridge National Laboratory

Klaus Ziock +1-865-574-0272 ziockk@ornl.gov

PHDS Co Ethan Hull Desmond Longford

+1-865-603-5640 ethanhull@phdsco.com deslongford@phdsco.com

A.3 List of observers:

Organization Representative Contact

IAEA

Mr Dimitri FINKER D.Finker@iaea.org

Mr Andrey BOSKO A.Bosko@iaea.org

Mr Iain DARBY I.Darby@iaea.org

Ms Taissa SOBOLEV T.Sobolev@iaea.org

Mr Andrey SOKOLOV A.Sokolov@iaea.org

Mr. Alain Lebrun A.Lebrun@iaea.org

USA Ms Anagha IYENGAR Anagha.Iyengar@NNSA.Doe.Gov

Ms Arden DOUGAN Arden.Dougan@NNSA.Doe.Gov

JRC Mr Arturs ROZITE Arturs.Rozite@jrc.ec.europa.eu

Mr Stefano VACCARO Stefano.Vaccaro@ec.europa.eu

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B. Technical characteristics of the participating systems

Device GeGI Gamma-ray Imaging HPGe Gamma-ray Imager

Manufacturer PHDS Co ORNL

Technology HPGe, Compton / pinhole HPGe, coded-mask, variable focal length Sensor size, mm 90 diameter x 10 thickness, 53 cm3 90 diameter x 10 thickness, 53 cm3

Sensor pixels 61 x 61 61 x 61 Field of view 4 Pi (Compton), 60° (pinhole) 12° – 110°

Energy range, MeV 0.14 – 3 (Compton), 0.04 – 0.6 (pinhole) 0.04 – 0.65 Size, cm 31 x 15 x 23 70 x 25 x 40

Weight, kg 14 35

Device iPix HiSpect

Manufacturer Canberra CEA

Technology CdTe, coded-mask CZT, coded-mask Sensor size, mm 14 x 14 x 1 40 x 40 x 5

Sensor pixels 256 x 256 256 pixels Field of view 41.4° – 48.8° 35°

Energy range, MeV 0.03-1.2 0.03 – 1.3 Size, cm 19 x 11 x 11 20 x 21 x 23

Weight, kg 2.5 7.5

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Device RadSearch Model G-3050 Polaris-H 3-dimensional position-

sensitive CdZnTe gamma-ray imaging spectrometer

Manufacturer ANTECH H3D

Technology LaBr3, collimated scanning CZT, Compton Sensor size, mm 25.4 diameter 6 cm3

Sensor pixels 1 121 pixels Field of view 4 Pi 4 Pi

Energy range, MeV 0-3 0.25 – 3 Size, cm 66 x 21 x 18 21 x 19 x 13

Weight, kg 24 + 13 (with tripod) 4

Device Next-gen mobile prototype High-Efficiency Multi-mode Imager

HEMI prototype

Manufacturer Createc LBNL

Technology CdTe, Compton

3D laser mapper + wide-angle cameras CZT, Compton Xbox sensor

Sensor size, mm 0.5 cm3 96 cm3 Sensor pixels 1 96 pixels Field of view 4 Pi 4 Pi

Energy range, MeV 0.03-1.8 0.05 – 3 Size, cm Prototype 25 x 18 x 18

Weight, kg Prototype 4

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C. Experiment protocol Experiment 1: Efficiency Objective To measure systems’ detection efficiency and energy resolution. Disclosed setup

Cameras positioned equidistantly from the target and pointed towards it. The background level is 50-70 nSv/h. A point source is positioned in the centre of the field of view; distance to the

source varies between 1.5 m and 5 m to ensure net dose rate in the range of 200-500 nSv/h (uniformity to be controlled during experiment by performing checks in different areas using external dose-rate instrument).

Isotope Description 1. If applicable, use coded aperture.

2. Make a long measurement (up to 15 minutes) of the source. 3. If necessary, complete the source library using the provided source. 4. Repeat with a different point source.

Data set 1. Spectra (background and measurements) collected within field of view 2. Peak net count rate within a defined energy RoI 3. Net dose rate

Assessment Total and net peak efficiency calculation (kcps/(nSv/h)) Energy resolution

Experiment 2: Overnight identification Disclosed objective

To identify and localize very weak extended source during overnight measurements

Disclosed setup

Cameras positioned equidistantly from the target and pointed towards it. The background level is 50-70 nSv/h. Calibration: a weak source is positioned behind the target, distance around 5 m

to ensure net dose rate about 50 nSv/h (uniformity to be controlled using external dose-rate instrument).

Experiment: weaker point source is positioned in the centre of the field of view, distance around 5 m, to ensure net dose rate about 50 nSv/h.

Description 1. If applicable, use coded aperture. Experiment may be repeated the next night with Compton-mode imaging.

2. Calibration: make a long measurement (up to 30 minutes) of the first source. Set up detection threshold such that to have less than 1 false detection in 1000 trials. General recommendation: in any case the detection threshold shall not be set less than 3 sigma values above background level.

3. Make necessary configurations for overnight measurements. 4. Experiment: repeat with a different point source with overnight measurements

(repetitive acquisitions of 30 min each). Data set 1. Times to detect (t1), identify (t2), and localize (t3) using providers’ algorithms.

Identification and localization confidence index shall be displayed. 2. When applicable: energy spectra for the complete field of view at t1, t2, and t3. 3. The full visual images with gamma false colour overlay and explanatory legends

at t1, t2, and t3. 4. The profile of the total counts along the x axis, and the count sum under each

peak at t1, t2, and t3. 5. Expert assessment of the target at this stage at t1, t2, and t3.

Assessment False alarm rate (number of false detections)

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Experiment 3: Sensitivity Objective Evaluate the detection capability by reporting the probability of correct/false

identification, time to detect, identify, and localize of various radiation sources, including nuclear materials.

Disclosed setup

Cameras positioned equidistantly from the target and pointed towards it. The background level is 50-70 nSv/h. A target source is positioned in the centre of the field of view, distance to the

source varies between 1.5 m and 5 m to ensure net dose rate about 50-200 nSv/h (uniformity to be controlled using external dose-rate instrument).

Description 1. Do not change camera settings of previous overnight measurement. If applicable, keep using coded-mask aperture.

2. Verify source library. 3. Make a series of short measurements (up to 10 minutes each) of each point

source 4. Repeat the same procedure with different sources.

Data set 1. Times to detect (t1), identify (t2), and localize (t3) using providers’ algorithms. Identification and localization confidence index shall be displayed.

2. Energy spectra, for the complete field of view at t1, t2, and t3. 3. The full visual images with gamma false colour overlay and explanatory legends

at t1, t2, and t3. 4. The profile of the total counts along the x axis, and the count sum under each

peak at t1, t2, and t3. 5. Expert assessment of the target at this stage at t1, t2, and t3.

Assessment Average time to detect, identify, localize for each isotope. Probability of correct identification.

Experiment 4: Field of view Objective Evaluate the uniformity of the sensitivity by measuring the efficiency in various

positions within the field of view. Disclosed setup

Cameras positioned equidistantly from the target and pointed towards it. The background level is 50-70 nSv/h. One point source is positioned in the centre of the field of view, distance to the

source is about 5 m and net dose rate about 200-500 nSv/h (uniformity to be controlled using external dose-rate instrument).

Description 1. If applicable, set up the coded-mask aperture. 2. Make a short measurement (up to 5 minutes) of the source. 3. Repeat the measurements of the same source by turning camera’s mount ball

head horizontally with step ~10° over imager’s field of view (9-10 measurements in total).

4. If applicable, change to Compton mode and repeat the measurement at 0°, 30°, and 90° (with different source).

Data set 1. Spectra collected within the field of view 2. Peak net count rate within a defined energy RoI 3. Net dose rate

Assessment Efficiency (kcps/(nSv/h)) as function of angle

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Experiment 5: Angular resolution Objective Evaluate the separation power at various positions within the field of view, by

measuring the minimal angle resolving two similar sources. Disclosed setup

Cameras positioned equidistantly from the target and pointed towards it. The background level is 50-70 nSv/h. Two point source of the same energy are positioned close one to another in the

centre of the field of view; distance to the sources is 5 m and net dose rate about 700 nSv/h (uniformity to be controlled using external dose-rate instrument).

Description 1. If applicable, set up the coded-mask aperture. 2. Make a short measurement (up to 5 minutes) of the sources. 3. Consecutively separate the sources on distances corresponding to 1°, 2°, 3°, 4°,

5° parallax; repeat measurement of the same sources each time. 4. Keep the sources at 5° and turn the cameras horizontally to angles 30°, 60° from

the sources; repeat the measurements. 5. If applicable, change to Compton mode and repeat the measurement at 0° and

30° (with different source). 6. If applicable, change to pinhole mode and repeat the measurement at 0°, 30°.

Data set 1. Time to separate 2. Energy spectra for the complete field of view 3. The full visual images with gamma false color overlay and explanatory legends 4. The profile of the total counts along the x axis, and the count sum under each

peak 5. Expert assessment of the location/separation

Assessment Minimum separation angle within the field of view Experiment 6: Extended source Objective Estimate the capabilities to assess the shape and dimensions of the nuclear materials

found in IAEA applications scenarios (fresh fuel, …) Disclosed setup

Cameras positioned equidistantly from the target and pointed towards it. The background level is 50-70 nSv/h. One extended source is positioned in the centre of the field of view; distance to

the source is 2 m and net dose rate about 100 nSv/h. Repeat the measurement with different setup.

Description 1. Choose the best setup between Compton / coded-mask aperture / pinhole. 2. Make a long measurement (up to 60 minutes) of the initial extended source.

Data set 1. Acquisition time 2. Energy spectra for the complete field of view 3. The full visual images with gamma false color overlay and explanatory legends 4. The profile of the total counts along the specified x axes, and the count sum

under each peak 5. Expert assessment of the nature/dimensions of the source

Assessment Identification, localization of the source Accuracy of the overall distribution of the material Level of detail of the geometry (active length, missing rods)

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Experiment 7: Masking scenario / high background Objective Estimate the capabilities to identify/localize the weak sources in non-uniform high

background conditions Disclosed setup

Cameras positioned equidistantly from the target and pointed towards it. The natural background level is 50-70 nSv/h. One weak point source (about 50 nSv/h) as a target is positioned about 2 m

away in the centre of the field of view; two strong point sources (500 nSv/h each) are positioned about 5 m away from the camera outside of the centre of the field of view to imitate higher background level. The target source is of different energy than the background sources.

Description 1. Measure background (up to 15 minutes) 2. Make a long measurement (up to 30 minutes) of the target source.

Data set 1. Times to detect (t1), identify (t2), and localize (t3) the target source using providers’ algorithms. Identification and localization confidence index shall be displayed.

2. Energy spectra for the complete field of view at t1, t2, and t3 3. The full visual images with gamma false colour overlay and explanatory legends

at t1, t2, and t3. 4. The profile of the total counts along the x axis, and the count sum under each

peak at t1, t2, and t3 5. Expert assessment of the target at this stage at t1, t2, and t3.

Assessment Identification, localization of the target source False alarm rate

Experiment 8: Angular resolution for extended sources Objective Evaluate the separation power of the instruments when resolving two similar

extended sources located in the centre of the field of view. Disclosed setup

Cameras positioned equidistantly from the target and pointed towards it. The background level is 50-70 nSv/h. Two strong LEU extended source are positioned close one to another in the

centre of the field of view; distance to the sources is 2.5 m and net dose rate about 200 nSv/h (uniformity to be controlled using external dose-rate instrument).

Description 1. If applicable, set up the coded-mask aperture. 2. Make a short measurement (up to 15 minutes) of the sources. 3. Repeat the measurement with the sources separated further one from another). 4. For Compton cameras, repeat the experiment with two point HBU Pu sources

with different activity levels (due to different shielding). Data set 1. Time to separate

2. Energy spectra for the complete field of view 3. The full visual images with gamma false colour overlay and explanatory legends 4. The profile of the total counts along the x axis, and the count sum under each

peak 5. Expert assessment of the location/separation

Assessment Minimum separation angle within the field of view

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D. Experiment setup Details for the sources and their locations are given in the table below individually for each measurement and experiment. The grid attached to the target screen is used as a coordinate map for referencing the sources; the notation (x; y) is for a point at x cells on the right from the central point (negative number corresponding to a shift on the left) and y cells above from the central point (negative number corresponding to a shift below the central point). Each cell on the grid is 5cm x 5 cm. For some measurements with a complex set of sources, a photo is provided; note that the photo is taken from behind the screen, so the source location is mirrored from the gamma cameras’ point of view.

Table 9 Experiment setup

ID Description E0 M0 No sources, background measurement E1 M1 No sources, background measurement E1 M2 Cs137 point source at (0; 0) E1 M3 Am-Li point source at (0; -2) E1 M4 Co60 point source at (0; -2) E2 M5 Shielded Cs137 point source at (0; -2) E2 M6 Overnight measurement setup with multiple calibration sources:

Cs137 point sources at (0; 0), (6; 0), (10; 0), (3, -4) U3O8 point source at (-1.5, -3) Cs132 point source at (0, 4.5) Co57 point source at (-5, -4)

E3 M7 No sources, background measurement E3 M8 HBU Pu point source at (0; 0) E3 M9 Same setup as E3 M8, shorter measurement E3 M10 LBU Pu point source at (0; 0) E3 M11 LBU Pu point source at (0; 3) E3 M12 Two LEU extended cylindrical sources with different thickness of the shielding; centres

at (-2; -1) and (2; -1); diameter of the sources ~15 cm.

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E3 M13 Two LEU extended cylindrical sources with different thickness of the shielding; one behind another at (0; -1). Diameter of the sources ~15 cm.

E3 M14 Two LEU extended cylindrical sources with different thickness of the shielding; centres at (-1; -6.5) and (2; -6.5). Diameter of the sources ~15 cm. 3D reconstruction experiment.

E3 M15 Two LEU extended cylindrical sources with different thickness of the shielding; centres at (-2; -1) and (2; -1); diameter of the sources ~15 cm. Point HBU Pu source at (0; 3) Point LBU Pu source at (5; -2) Empty box with the centre at (-6; -1)

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E3 M16 Same configuration as E3 M15. 3D reconstruction experiment. E3 M17 Stack of 12 MTR plates put horizontally between (-6; -1) and (5; -1).

Length of the plates ~60 cm, width ~7 cm

E4/5 M18 2 point Am-Li sources at (-5; -2) and (5; -2). Distance between sources ~50 cm. E4/5 M19 2 point Am-Li sources at (-5; -2) and (5; -2). Distance between sources ~50 cm.

E4/5 M20 2 point Am-Li sources at (-3; -2) and (3; -2). Distance between sources ~30 cm. E4/5 M21 2 point Am-Li sources at (-2; -2) and (2; -2). Distance between sources ~20 cm. E4/5 M22 2 point Am-Li sources at (-2; -2) and (0; -2). Distance between sources ~10 cm. E4/5 M23 Target grid moved 1m to the right from the centre of the FOV. 2 point Am-Li sources

at (1; -2) and (5; -2). Distance between sources ~20 cm. E4/5 M24 Target grid moved 1m to the right from the centre of the FOV. 2 point Am-Li sources

at (0; -2) and (6; -2). Distance between sources ~30 cm.

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E4/5 M25 Same setup as E4/5 M24. 3D reconstruction experiment. E4/5 M26 Cs137 point source at (-2; -1)

Shielded Co60 source at (2; -1)

E4/5 M27 Shielded Co60 source at (-2; -1) Cs137 point source at (4; -1)

E4/5 M28 Shielded Co60 source at (0; -1) Cs137 point source directly on it, at (0; 0)

E5 M29 Overnight measurement without any sources. E6 M30 No sources, background measurement. E6 M31 Multiple MTR plates and point sources.

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E7 M32 HBU Pu source at (0; 0)

HBU Pu source at (-5; 0) LBU Pu source at (5; 0) LBU Pu source at (0; -6)

E7 M33 The stronger sources from E7M32 were removed. Remaining sources: HBU Pu source at (0; 0) LBU Pu source at (5; 0)

E7 M34 Same setup as E7 M33, just moved closer to the camera racks. E7 M35 Same setup as E7 M34 plus Co60 point source added 3.5m aside and behind the

screen (to imitate the background), but in the FOV of the cameras. E7 M36 Same setup as E7 M35, but Co60 point source was replaced behind the camera rack

outside the FOV of the cameras. E7 M37 No sources, overnight false-alarm measurement. E7 M38 No sources, background measurement. E8 M39 Stack of 6 MTR plates vertically from (-1.5; -5) to (-1.5; 7)

Stack of 5 MTR plates vertically from (1.5; -5) to (1.5; 7)

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Width of one plate ~7 cm, length ~60 cm Distance between stacks ~7 cm.

E8 M40 Stack of 6 MTR plates vertically from (-3; -5) to (-3; 7) Stack of 5 MTR plates vertically from (3; -5) to (3; 7) Distance between stacks ~20 cm.

E7 M41 HBU Pu source with thin shielding at (-3; -1) HBU Pu source with thick shielding at (3; -1)

E8 M42 HBU Pu source with thin shielding at (-2; 0) HBU Pu source with thick shielding at (2; 0)

E9 Glove box scenario, target screen is not used.