Publications

Fusion Engineering and Design

Nygren, Richard E.; Youchison, D.L.; Michael, Joseph R.; Puskar, J.D.; Lutz, Thomas J.

In preparation for testing a lithium-helium heat exchanger at Sandia, unexpected rapid failure of the mild steel lithium preheater due to liquid metal embrittlement occurred when lithium at ~400 °C flowed into the preheater then at ~200 °C. This happened before the helium system was pressurized or heating with electron beams began. The paper presents an analysis of the preheater plus a discussion of some implications for fusion.

Nygren, Richard E.; Youchison, Dennis L.; Michael, Joseph R.; Puskar, J.D.; Lutz, Thomas J.

Abstract not provided.

Nygren, Richard E.; Youchison, Dennis L.; Michael, Joseph R.; Puskar, J.D.; Lutz, Thomas J.

Abstract not provided.

Nygren, Richard E.; Youchison, Dennis L.; Michael, Joseph R.; Puskar, J.D.; Lutz, Thomas J.

Abstract not provided.

Youchison, Dennis L.; Michael, Joseph R.; Puskar, J.D.; Lutz, Thomas J.

Abstract not provided.

Youchison, Dennis L.; Lutz, Thomas J.

Abstract not provided.

Youchison, Dennis L.; Lutz, Thomas J.; Nygren, Richard E.

Abstract not provided.

McDonald, Jimmie M.; Lutz, Thomas J.

Abstract not provided.

McDonald, Jimmie M.; Lutz, Thomas J.

Abstract not provided.

Natoni, Gregory N.; Youchison, Dennis L.; Garde, J.; Sharpe, Robin A.; Bauer, F.J.; Lutz, Thomas J.; McDonald, Jimmie M.

Abstract not provided.

Lutz, Thomas J.; McDonald, Jimmie M.; Youchison, Dennis L.; Ulrickson, M.A.; Nygren, Richard E.

Abstract not provided.

Lutz, Thomas J.; Youchison, Dennis L.; McDonald, Jimmie M.; Ulrickson, M.A.; Nygren, Richard E.

Abstract not provided.

Fusion Engineering and Design

Youchison, Dennis L.; Lutz, Thomas J.; Williams, B.; Nygren, Richard E.

Utramet, Inc. fabricated one-piece heat exchanger tubes of chemical vapor deposited (CVD) tungsten (W), each with an internal porous mesh fused along either 51 or 38 mm of the axial length of a tube 15 mm in outer diameter. The open porous mesh has a structure of joined ligaments that combines relatively low resistance to flow and a large area for heat transfer. In tests at the Electron Beam Test Stand (EBTS) at Sandia National Laboratories, the maximum absorbed heat load was 22.4 MW/m2 with helium at 4 MPa, flowing at 27 g/s and with inlet and outlet temperatures of 40 and 91 °C and a pressure drop of ∼0.07 MPa. The preparation and testing of the samples was funded through a Phase I grant by the US Department of Energy's Small Business Innovation Research Program. The paper reports the surface temperature distribution indicated by an infrared camera, test conditions, a post-test examination in a scanning electron microscope and other details. © 2007 Elsevier B.V. All rights reserved.

McDonald, Jimmie M.; Lutz, Thomas J.; Ulrickson, M.A.; Martin, Tina T.; Youchison, Dennis L.; Nygren, Richard E.

Abstract not provided.

McDonald, Jimmie M.; Lutz, Thomas J.; Ulrickson, M.A.; Martin, Tina T.; Youchison, Dennis L.; Nygren, Richard E.

Abstract not provided.

Fusion Engineering and Design

Nygren, Richard E.; Ulrickson, M.A.; Tanaka, T.J.; Youchison, Dennis L.; Lutz, Thomas J.; Bullock, J.; Hollis, K.J.

The US will supply outboard Module 18 for the International Thermonuclear Experimental Reactor. This module, radially thinner than other modules with a "nose" that curves radially outward to mate with the divertor, has the potential for high electromagnetic (EM) loads from vertical displacement events and high heat loads. The 316LN-IG shield block and first wall (FW) panels must be slotted to mitigate the EM loads and progress in developing the design is summarized. The FW has beryllium (Be) armor joined to a water-cooled CuCrZr heat sink with embedded 316LN-IG cooling channels. The US Team is considering possible fabrication methods as the design develops. Brief results of high heat flux experiments at Sandia on mockups with plasma-sprayed Be armor prepared at Los Alamos National Laboratory are noted. © 2005 Elsevier B.V. All rights reserved.

Fusion Engineering and Design

Tanaka, T.J.; Bauer, F.J.; Lutz, Thomas J.; McDonald, Jimmie M.; Nygren, Richard E.; Troncosa, K.P.; Ulrickson, M.A.; Youchison, Dennis L.

This paper describes the liquid metal integrated test system (LIMITS) at Sandia National Laboratories1. This system was designed to study the flow of molten metals and salts in a vacuum as a preliminary study for flowing liquid surfaces inside of magnetic fusion reactors. The system consists of a heated furnace with attached centrifugal pump, a vacuum chamber, and a transfer chamber for storage and addition of fresh material. Diagnostics include an electromagnetic flow meter, a high temperature pressure transducer, and an electronic level meter. Many ports in the vacuum chamber allow testing the thermal behavior of the flowing liquids heated with an electron beam or study of the effect of a magnetic field on motion of the liquid. Some preliminary tests have been performed to determine the effect of a static magnetic field on stream flow from a nozzle. © 2004 Elsevier B.V. All rights reserved.

Youchison, Dennis L.; Lutz, Thomas J.; McDonald, Jimmie M.; Nygren, Richard E.

Abstract not provided.

Surface and Coatings Technology

Youchison, Dennis L.; Gallis, Michail A.; Nygren, Richard E.; McDonald, Jimmie M.; Lutz, Thomas J.

The development of advanced thermal barrier coatings of yttria stabilized zirconia (YSZ) that exhibit lower thermal conductivity through better control of electron beam-physical vapor deposition (EB-PVD) processing is of prime interest to both the aerospace and power industries. Recently, processing technology was developed to create graded TBCs by coupling ion beam assisted deposition (IBAD) with substrate pivoting in the alumina-YSZ system. The Electron Beam-1200 kW (EB-1200) PVD system was used to deposit a variety of TBC coatings with micron layered microstructures and reduced thermal conductivity of 1.5 W/mK. The use of IBAD produced fully stoichiometric coatings at a reduced substrate temperature of 600 °C and a reduced oxygen background pressure of 0.1 Pa. In addition to the process technology, the results of Direct Simulation Monte Carlo plume modeling and spectroscopic characterization of the PVD plumes are presented. © 2003 Elsevier B.V. All rights reserved.

Nygren, Richard E.; Youchison, Dennis L.; McDonald, Jimmie M.; Lutz, Thomas J.; Miszkiel, Mark E.

In the authors initial high heat flux tests on small mockups armored with W rods, done in the small electron beam facility (EBTS) at Sandia National Laboratories, the mockups exhibited excellent thermal performance. However, to reach high heat fluxes, they reduced the heated area to only a portion ({approximately}25%) of the sample. They have now begun tests in their larger electron beam facility, EB 1200, where the available power (1.2 MW) is more than enough to heat the entire surface area of the small mockups. The initial results indicate that, at a given power, the surface temperatures of rods in the EB 1200 tests is somewhat higher than was observed in the EBTS tests. Also, it appears that one mockup (PW-10) has higher surface temperatures than other mockups with similar height (10mm) W rods, and that the previously reported values of absorbed heat flux on this mockup were too high. In the tests in EB 1200 of a second mockup, PW-4, absorbed heat fluxes of {approximately}22MW/m{sup 2} were reached but the corresponding surface temperatures were somewhat higher than in EBTS. A further conclusion is that the simple 1-D model initially used in evaluating some of the results from the EBTS testing was not adequate, and 3-D thermal modeling will be needed to interpret the results.