Optimization of the U.S. Army's Fast Neutron Moderator for Radiography
[Technical Report, Final Report]
CCDC AC, ESIC, FCDD-ACE-QEA
Pagination or Media Count:
Early experiments in neutron radiography NR have been demonstrated at the U.S. Army Combat Capabilities Development Command Armaments Center CCDC AC, Picatinny Arsenal, NJ. From the early 1970s through the 1980s, neutron imaging was done using Californium-252 and showed significant potential for expansion into a nondestructive testing method that would be viable to inspect munitions and weapon systems. However, due to the inherent issues involved with the use of radioactive sources and the high costs and numerous requirements for operating a reactor or research accelerator, little progress has been made since that time. The NR has not been widely implemented for use within the Department of Defense, mainly due to the limitations of available neutron producing sources. Current commercially available electronic sources and generators are impractical for imaging due to low outputs, which require exposure times measured in days, not minutes, as is typical for x-ray imaging. These conditions were shown in the initial baseline experiments performed at CCDC AC with a commercial source. The early tests showed promise in the method but reinforced the need for a high-output, small-size, easy-to-use neutron source. This paper presents a more in-depth investigation into the optimization of a laboratory NR imaging system and its potential for nondestructive inspection directly applicable to defense components. This upgraded NR setup uses a moderator and collimator specifically designed for use with the 14.1 MeV neutrons from a deuterium-tritium generator. The field of view was also increased for more practical use with standard 35 cm L x 43 cm W 14 in. L x 17 in. W radiographic cassettes and film. The goal of this experiment was to have increased thermal neutron flux rates and shorter exposure times than previously achieved. Additional technology developments are also underway to build state of the art neutron sources for the U.S. Army.
- Test Facilities, Equipment and Methods