Precipitate Size in GRCop-84 Gas Atomized Powder and Laser Powder Bed Fusion Additively Manufactured Material

Data for: Precipitate Size in GRCop-84 Gas Atomized Powder and Laser Powder Bed Fusion Additively Manufactured Materia

Data for: Precision Measurement of Relative Permittivity of Aluminum Oxide for a High Power Resonant Waveguide Window with Low Return Loss

Data from plotted figure

Data for: Nuclear Response of Additive Manufactured GRCop-84 Copper for use in Lower Hybrid Launchers in a Fusion Environment

Nuclear Response of Additive Manufactured GRCop-84 Copper for use in Lower Hybrid Launchers in a Fusion EnvironmentA. H. Seltzman*, S. J. WukitchMassachusetts Institute of Technology, Plasma Science and Fusion Center, 190 Albany St, Cambridge, MA, 02139(Received dd month 2020; published dd month 2020)Recent advances in selective laser melting (SLM) 3D printing technology allow additive manufacture of lower hybrid current drive (LHCD) RF launchers from a new material, Glenn Research Copper 84 (GRCop-84), a Cr2Nb (8 at. % Cr, 4 at. % Nb) precipitation hardened alloy, in configurations unachievable with conventional machining. Tensile strength and thermal conductivity are compared to other competing high conductivity copper alloys for fusion use. Swelling and conductivity at 100 DPA is predicted in the 1-2% and 65-70% IACS range, respectively by comparison to copper alloys with similar precipitate and grain size. Self-similar ion irradiation of a GRCop-84 target at 430°C to 20 DPA resulted in no noticeable void formation

Brazing Characteristics and Wettability of Laser Powder Bed Fusion Additive Manufactured GRCop-84 compared to CuCrZr and OFC, and Brazing to Titanium-Zirconium-Molybdenum Alloy Limiters

Laser Powder Bed Fusion (L-PBF) of Glenn Research Copper 84 (GRCop-84), a Cr2Nb (8 at. % Cr, 4 at. % Nb) precipitation hardened alloy, produces a fully dense, high conductivity alloy with a yield strength of 500 MPa and ultimate tensile strength (UTS) of 740 MPa with 20% elongation; superior to other competing copper alloys. Braze wetting characteristics of GRCop-84 with Ag-Cu-X, and Au-Cu brazes were similar to CuCrZr, but less than oxygen free copper. No difference in wetting was observed between infill and surface contour areas in L-PBF GRCop-84. Wet sanding to 240 grit (Ra=0.24 µm) was considered the optimal surface condition. Silver diffusing through GRCop-84 depleted Cr2Nb precipitates from the copper grain and deposited agglomerations of coarsened precipitates within silver-rich regions of intergranular diffusion once a density threshold was reached. Microstructure modification was minimized with 50Au-50Cu braze implying that silver caused precipitate coarsening and agglomeration, and not high temperature exposure. Coarsened precipitates were observed on the surface within braze pools implying a contribution to braze wetting. Palcusil-25, Ticusil, CuSil-ABA, and 50Au-50Cu brazes were suitable for brazing to unplated Titanium-Zirconium-Molybdenum (TZM), while sulfamate nickel plating to allows wetting with CuSil or other non-active brazes. Vacuum brazing techniques were developed to join a 1 mm thick layer of TZM to the front of additive manufactured GRCop-84 waveguides considering the brazing characteristics of both GRCop-84, TZM, and internal stress from the difference in coefficient in thermal expansion.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Surface Roughness and Finishing Techniques in Selective Laser Melted GRCop-84 Copper for an Additive Manufactured Lower Hybrid Current Drive Launcher

Data and figures for: Surface Roughness and Finishing Techniques in Selective Laser Melted GRCop-84 Copper for an Additive Manufactured Lower Hybrid Current Drive LauncherTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Data for: Precision Measurement of Relative Permittivity of Aluminum Oxide for a High Power Resonant Waveguide Window with Low Return Loss

Data from plotted figuresTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

A high field side multijunction launcher with aperture impedance matching for lower hybrid current drive in DIII-D advanced tokamak plasmas

A high field side (HFS) lower hybrid current drive launch scenario improves wave accessibility, has single pass damping at r/a ~ 0.6–0.8 and good current drive efficiency in DIII-D advanced tokamak discharges. The DIII-D experiment is an opportunity to validate HFS wave propagation, absorption and scrape-off layer benefits. A HFS multi-junction launcher is designed and simulated in COMSOL over a range of plasma edge conditions to evaluate n|| spectrum, directivity, and return loss. The COMSOL model utilizes a lossy anisotropic dielectric modeled with the cold plasma dispersion relation cross validated against ALOHA and Petra-M codes. The COMSOL model seamlessly includes a realistic plasma model and coupler that allows for rapid optimization of a single launcher module, while Petra-M allows more complex simulation of an eight-module array including curvature, and warm plasma effects. The resulting design utilizes a traveling wave poloidal power divider to minimize peak electric fields in the vacuum region of the coupler, and an internal aperture matching structure provides an impedance match to the plasma over a wide range of plasma density and density gradient edge conditions.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Resolution and Geometric Limitations in Laser Powder Bed Fusion Additively Manufactured GRCop-84 Structures for a Lower Hybrid Current Drive Launcher

Laser Powder Bed Fusion (L-PBF), also known as Selective Laser MeltingTM (SLMTM), allows additive manufacture of lower hybrid current drive (LHCD) Radio Frequency (RF) launchers from a new material, Glenn Research Copper 84 (GRCop-84), a Cr2Nb (8 at. % Cr, 4 at. % Nb) precipitation hardened alloy, in configurations unachievable with conventional machining. The resolution and geometric limitations are tested to explore the limitations of L-PBF printing of GRCop-84. Printing holes in the vertical and horizontal direction are examined to determine the minimum cooling channel diameter. Internal stress limits the minimum thickness of vertical walls and septa to 1 mm, thinner walls warp during printing. Roughness is minimized on vertical surfaces and increases on both upper and lower surfaces as angle increases. Accuracy within 40 μm is typical on well supported structures