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Partially-reflected-plutonium-sphere.jpeg(471 × 363 pixels, file size: 56 KB, MIME type: image/jpeg)
Description A sphere of plutonium surrounded by neutron-reflecting blocks of tungsten carbide. A re-creation of the August 21, 1945 criticality accident at Los Alamos to measure the radiation produced when an extra block was added, making the mass supercritical.
Date 2 October 1945
Source From LANL's report on criticality accidents, 2000, PDF at
Author Los Alamos National Laboratory
( Reusing this file)
Public domain This image is a work of a United States Department of Energy (or predecessor organization) employee, taken or made as part of that person's official duties. As a work of the U.S. federal government, the image is in the public domain.

Please note that national laboratories operate under varying licences and some are not free. Check the site policies of any national lab before crediting it with this tag.

Specifically, this image comes from Los Alamos National Laboratory. LANL requires the following text be used when crediting images to it: ( link)

Unless otherwise indicated, this information has been authored by an employee or employees of the University of California, operator of the Los Alamos National Laboratory under Contract No. W-7405-ENG-36 with the U.S. Department of Energy. The U.S. Government has rights to use, reproduce, and distribute this information. The public may copy and use this information without charge, provided that this Notice and any statement of authorship are reproduced on all copies. Neither the Government nor the University makes any warranty, express or implied, or assumes any liability or responsibility for the use of this information.

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