NMIS Software and Imaging Jim Mullens December 2004

NMIS Software and Imaging Jim Mullens December 2004 VNIIEF/ORNL WWSX Work Review Meeting December 14 -16, 2004 VNIIEF Sarov, Russia

On-Going NMIS Software Modifications · FPGA board support of: - HOS & SCH measurement Long correlation blocks Dual boards Combined detector signals for correlations New FGPA code Other signal processing enhancements SOFTWARE ARCHITECTURE IS IN PLACE · IDAS support of HOS (3 D graphs) & SCH (display with correlations) - GRAPHIC LIBRARY 3 D PLOT FUNCTION IS USED, - VISUALIZATION TOOLKIT (VTK) BEING CONSIDERED AS REPLACEMENT - ARCHITECTURE IN PLACE TO DISPLAY SCH AND CORRELATIONS TOGETHER · DAUI automated detector calibration using 252 Cf - MOST OF CODE WRITTEN, NEEDS TESTING · Measurement results file improvements (more information) - MOSTLY DONE OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 2

On-Going NMIS Software Modifications · Russian messages for operators - WILL INSERT MESSAGES AS THEY ARE AVAILABLE; USING UNICODE EXCLUSIVELY · Addition of RF contributed analysis code - TO BE DONE: ONE MODULE IS WRITTEN IN VISUAL BASIC · Image processing is done off-line for now - INCORPORATED AT SOME FUTURE DATE - SOME SUPPORT FOR IMAGE ACQUISITION IN DAUI · Sci. Lab (Mat. Lab-like math analysis) to be available on NMIS computer · Matching simplified or removed from IDAS - FUTURE MATCHING WORK WILL START OFF-LINE IN MATLAB/SCILAB, THEN BE INCORPORATED INTO IDAS · General software clean up - Removing unused and experiment code, adding comments, reorganizing OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 3

Tomographic Imaging of Fissile Materials Using Neutrons and Gamma Rays · Interrogation using 252 Cf or DT generator poly rod · Use of both γ rays and neutrons gives materials information (contrasting γ and n cross sections) Uranium cylinder wall steel can OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 4

Image Reconstruction Examples Attenuation Measured on a 2 D Slice through the Target (casting plus a plastic rod in the center) Aluminum / D-T HEU / Cf neutron HEU / D-T HEU / Cf gamma OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 5

Imaging Measurement Using D-T Generator with Emission Cone Measure attenuation due to containerized material at each detector. OVERHEAD VIEW 24 detector positions, using 8 1 x 1 x 6” plastic detectors SIDE VIEW OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 6

Imaging Detectors and DT Generator (w/o Target) OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 7

DT Generator, Test Target, and Imaging Detectors OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 8

Radiation Attenuation Seen by Each Detector (D-T Generator, 14. 1 Me. V Neutrons) simulated measured Attenuations seen across the detector array are the basis for the image reconstruction. The cylinders’ walls attenuations are visible. Interpretation of complex objects is not straightforward. This measurement varies from model prediction. OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 9

Parametric Image Reconstruction 1. Use a simple model of the physics and target, having a few variable parameters: cross sections, dimensions. 2. Iteratively vary the model parameters until the model prediction agrees with the measurement. Fit to MCNPPolimi simulated measurement OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 10

Reconstruction Parameters · Materials - Attenuation in each region of the target (7 values) · Dimensions - Radius of each cylinder of plastic, plastic beads, steel, air (7 values) - Offset of target (1 x, y value) - Offset of central cylinders w. r. t. outer plastic bottle (1 x, y value) OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 11

Parametric Image Reconstruction: Measured and Fitted Projection 1. Fit found that target was off center by about 4 mm. This explains much of the difference between the prediction and the measurement (right side). OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 12

Object: Actual and Reconstructed Using Parametric Reconstruction Target cylinders viewed from above. ACTUAL STEEL MEASUREMENT PLASTIC AIR OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 13

CONCLUSIONS · Lab tests and MCNP-Polimi simulations show that imaging works · Imaging is being incorporated into the US NMIS · Measurements with US weapons components will be performed this year OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY 14