| AVS 63rd International Symposium & Exhibition | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS-ThP |
| Session: | Plasma Science and Technology Division Poster Session |
| Presenter: | Frank Lopez, Los Alamos National Laboratory |
| Authors: | F.E. Lopez, Los Alamos National Laboratory H.W. Herrmann, Los Alamos National Laboratory J.A. Oertel, Los Alamos National Laboratory S.H. Batha, Los Alamos National Laboratory Y.H. Kim, Los Alamos National Laboratory J.R. Griego, Los Alamos National Laboratory T.N. Archuleta, Los Alamos National Laboratory R.J. Aragonez, Los Alamos National Laboratory V.E. Fatherley, Los Alamos National Laboratory C.S. Young, Los Alamos National Laboratory A. Hsu, Los Alamos National Laboratory R.M. Malone, Los Alamos National Laboratory |
| Correspondent: | Click to Email |
The development of the LANL Gas Cherenkov Detector (GCD-3) fielded at the Laboratory for Laser Energetics OMEGA laser facility generated significant engineering challenges. The GCD-3 is a third-generation gas Cherenkov diagnostic that provides important information about Inertial Confinement Fusion (ICF) implosions including fusion burn and imploded capsule conditions. The GCD-3 utilizes CO2, SF6 and C2F6 gases separately pressurized at 400psig to provide the scintillation media. Unique experimental objectives contrasted with the requirements of the ASME Boiler and Pressure Vessel (B&PV) Code resulted in diverging pressure vessel concepts throughout the design process. In addition, a facility-specific weight limitation and stringent fluorinated gas leak rate requirements added to the complexity of the diagnostic’s development. Specifically, achieving a vessel/detector weight limit of 100 pounds in conjunction with a maximum fluorinated gas leak rate of 1X10E-9 STD cc/second (helium) at 1 atmosphere differential pressure proved to be challenging. As such, Conflat knife-edge crushed-metal seals were an essential aspect of the design. The LANL Pressure Safety Program in compliance with DOE Order 10CFR851 invokes the ASME Boiler and Pressure Vessel Code, Section VIII, Division I and II for the design of all pressure vessels. As the B&PV Code can be characterized as a “one size fits all” standard, the tendency toward conservatism is typical. Vessel wall and flange thicknesses are routinely substantial, although inconsequential to refineries, are atypical of pressurized ICF diagnostics. A detailed summary of these design challenges correlated with the resulting experimental results bring emphasis to the successful collaborative mix of engineering and physics expertise within the ICF diagnostic development arena.