Physics Division activities in standoff active-interrogation for detecting terrorist nuclear devices, 2011
Detonation of a terrorist nuclear device in a major city would have severe economic, psychological and cultural consequences. To help prevent the fulfillment of such a threat, Physics Division has been exploring techniques by which highly-enriched uranium could be detected before reaching its intended target. We have focused on the use of high-energy protons and negative-muons because of their ability to probe deeply into structures and shielding that would surround the uranium, and their capability to stimulate radiation signatures indicating 235U.
Our experimental studies for standoff active-interrogation are enabled by the 800-MeV proton beam at the Los Alamos Neutron Science Center, which supports both the direct application of protons and their spallation neutrons, and the production of negative-pions that decay into negative muons. This work has been supported by the Defense Threat Reduction Agency, and involves Physics Division senior scientists, our Subatomic Physics Group (P-25) and several other organizations at Los Alamos, including groups for Accelerator and Beam Science (AOT-ABS), High Power Electrodynamics (ISR-6) and International and Nuclear Systems Engineering (D-5).
|Schematic of pion-capture solenoid experiment. The LANSCE 800MeV proton beam provides negative pions and muons in a strong magnetic field for the DTRA-sponsored muon active-interrogation program.|
|As part of DTRA-sponsored effort in protons for standoff active-interrogation, LANL scientists align graphite blocks in the path of an 800-MeV proton beam in front of a shielded test object to simulate the effects of protons causing spallations while traversing many meters of atmosphere before striking the object.|