ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
Sep 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
October 2025
Nuclear Technology
September 2025
Fusion Science and Technology
Latest News
NNSA awards BWXT $1.5B defense fuels contract
The Department of Energy’s National Nuclear Security Administration has awarded BWX Technologies a contract valued at $1.5 billion to build a Domestic Uranium Enrichment Centrifuge Experiment (DUECE) pilot plant in Tennessee in support of the administration’s efforts to build out a domestic supply of unobligated enriched uranium for defense-related nuclear fuel.
K. C. Chen, R. C. Cook, H. Huang, S. A. Letts, A. Nikroo
Fusion Science and Technology | Volume 49 | Number 4 | May 2006 | Pages 750-756
Technical Paper | Target Fabrication | doi.org/10.13182/FST06-A1196
Articles are hosted by Taylor and Francis Online.
One of the current capsule designs for achieving ignition on the National Ignition Facility (NIF) is a 2 mm diameter graded Ge-doped CH shell that has a 160 m thick wall. The Ge doping is not uniform, but rather is in radial steps. This graded Ge-doped design allows rougher surface finish than the original undoped CH design, thus has a less stringent surface roughness requirement.We selected quality mandrels by coating dozens of mandrel batches to ~70 m thickness to amplify submicrometer defects on the mandrels and successively removed inferior batches. The Ge-doped CH layers are made by introducing (CH3)4Ge to the gas stream. The doping concentrations were determined by performing trial runs and were characterized by X-ray fluorescence and quantitative radiographic analyses, with good agreement between the methods demonstrated.The precise layer thickness and Ge concentrations were determined by a non-destructive quantitative contact radiograph. The as-deposited average layer thicknesses of the shells were 9.5 ± 1.1 m for inner undoped CH layer, followed by a 47.1 ± 0.5 m thick 0.83 ± 0.09 at. % Ge-doped CH, 10.0 ± 0.4 m thick 0.38 ± 0.04 at. % Gedoped CH and then 89.2 ± 0.5 m of undoped CH.The atomic force microscope derived power spectrum of the shell meets the new NIF standard. The shells had a root-mean-square surface roughness of ~ 24 nm (modes 100-1000). The few surface flaws are isolated domes ~1 m tall and 20 m in diameter.The PAMS mandrels were successfully removed by pyrolysis at 305°C for 10-20 h. After pyrolysis, the diameter and wall shrank 0.4% and 5.7%, respectively. Except for the outer undoped CH layer, which was 5.8 m less than the design specification, the average thicknesses of the three other layers met the NIF design specification after pyrolysis. The averages of the Ge doping concentrations were within the tolerance limits. The shell's inner surface has root-mean-square roughness of less than 6.5 nm.