A standard for list-mode data Advantages in nuclear security

Transcription

1 The European Commission s science and knowledge service Joint Research Centre A standard for list-mode data Advantages in nuclear security MAGIC MAGGIORE - JRC/GICNT Technical Reachback Workshop March 2017 Jan Paepen (JRC)

2 Digital data acquisition in list-mode Main differences with conventional acquisition Analog-to-digital conversion at the beginning of the electronics chain Signal processing and logic in software and firmware (programmable electronics) Data is presented event per event Data is time-stamped 2

3 Conventional spectrometry Time when interactions took place is not stored Energy information is accumulated in a histogram, regularly updated List-mode: event per event Time and energy of every interaction is stored detector list-mode data acquisition continuous data stream (time, energy)... (time, energy)... (time, energy)... data analysis Energy histogram can be constructed over any time interval ð Combine time and energy with other information! 3

4 Advantages of digital list-mode data acquisition Easy to combine and process signals, especially when they are time-correlated From different detectors With other information, e.g. position and orientation of a mobile detector Store data obtained at an early stage in the electronics chain Later processing Re-analysing data with different algorithms or parameters Share raw data with others for analysis: scientists nuclear physics expert support teams nuclear security Enhances quality control and confidence in measurements 4

5 Radiation detection and measurement systems benefit from list-mode technology Nuclear safety and security Gamma/neutron pulse shape discrimination ( 3 He alternatives) Active interrogation systems Compton imaging Source localisation with mobile systems... Ease of system integration Raw data to experts / reachback / decision support centres Safeguards & nuclear waste assay Added value over conventional shift-register approach Spatial distribution of nuclear material No need to recalibrate the complete system when one detector fails Background suppression from muons and environmental neutrons Measurement of radioactivity Accurate laboratory measurements Store data obtained directly at detector output Apply different analysis methods on the same data Nuclear physics Correlate events from several detectors Extract more relevant signal characteristics Share data 5

6 Source localisation with mobile systems European Land Robot Trial, ELROB, 2016 Robot tasks Issue 1. build a 3D map robot moves too fast (up to 2 m/s) for 2. build a radiation map conventional data acquisition (using small detectors) ð robot passed the source 3. locate sources (next*: retrieve) ð list-mode data provides a solution 6 *European Robotics Hackathon, ENRICH, June 2017

7 Main issue with list-mode data THE LACK OF A STANDARD DATA FORMAT HINDERS THE INTEROPERABILITY BETWEEN HARD- AND SOFTWARE Hardware developers create their own proprietary format Developers of software for data analysis need data conversion Users/system integrators are not free to select hardware and software data acquisition data file data analysis data acquisition standard data file data analysis 7

8 A new standard is being prepared IEC/TC 45 "Nuclear instrumentation" Provides experts (WG 9) Represents industry Publishes the International Standard EMPIR "DigitalStandard" Consortium Provide comments: Metrologically sound? Develop software tools for compliance verification, generation of test data, basic analysis and conversion IEC Liaison cat. A with IEC/TC 45 JRC leads development Drafts, collects comments Ø Reach consensus JRC EU MS labs First to implement the standard Invited via publication in Official Journal of the EU* Pre-normative Implement research drafts Mandate M/487 Provide to comments CEN Test equipment at JRC Equipment manufacturers 8 *

9 What is the list-mode standard? IEC is: Binary, for performance reasons Canonical, to enable encryption and authentication Applicable to data files and streams Easy to implement: uses ASN.1 (Abstract Syntax Notation One ISO/IEC 8824) 9 Tools generate code for many programming languages and platforms: data structures and encoding/decoding routines Successful implementation of first Committee Draft in 1 day by a manufacturer Complementary to IEC "Radiation protection instrumentation - Data format for radiation instruments used in the detection of illicit trafficking of radioactive materials" (= ANSI N42.42) Extensible: upward compatibility with future revisions (and downward) IEC is NOT: For medical applications For instrument control/remote operation Ø Reason: standards exist already

10 What data types can IEC represent? Following types can be mixed: Pulses Values (and flags) derived from a pulse Digital signals Signal samples versus time Time Clock synchronisation, total dead time and live time Logic signals or transitions Position and orientation of detectors or other objects Measurements of any kind Histograms Any text or binary message can contain IEC data From max. 256 input channels 10

11 Conclusion Recent digital data acquisition systems offer advantages over conventional modular electronics Integration of security systems and interoperability between hardware and software is hindered by lack of a standard for list-mode data acquired by digital data acquisition systems A standard (IEC 63047) is being developed by TC 45 "Nuclear Instrumentation" Currently in the Committee stage Forecast publication date: March 2019 IEC NUCLEAR INSTRUMENTATION - DATA FORMAT FOR LIST-MODE DIGITAL DATA ACQUISITION USED IN RADIATION DETECTION AND MEASUREMENT

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