Publications

McGregor, Duncan A.; Love, Edward L.; Sirajuddin, David S.; Swan, Matthew S.; Collins, David I.; Pawlowski, Roger P.; Cartwright, Keith C.; Stafford, David S.

This is the user manual for EMPIRE, a simulation code for electromagnetics and plasma physics.

Cartwright, Keith C.; Pointon, Tim P.; Powell, Troy C.; Grabowski, Theodore C.; Shields, Sidney S.; Sirajuddin, David S.; Jensen, Daniel S.; Renk, Timothy J.; Cyr, Eric C.; Stafford, David S.; Swan, Matthew S.; Mitra, Sudeep M.; McDoniel, William M.; Moore, Christopher H.

This report documents the progress made in simulating the HERMES-III Magnetically Insulated Transmission Line (MITL) and courtyard with EMPIRE and ITS. This study focuses on the shots that were taken during the months of June and July of 2019 performed with the new MITL extension. There were a few shots where there was dose mapping of the courtyard, 11132, 11133, 11134, 11135, 11136, and 11146. This report focuses on these shots because there was full data return from the MITL electrical diagnostics and the radiation dose sensors in the courtyard. The comparison starts with improving the processing of the incoming voltage into the EMPIRE simulation from the experiment. The currents are then compared at several location along the MITL. The simulation results of the electrons impacting the anode are shown. The electron impact energy and angle is then handed off to ITS which calculates the dose on the faceplate and locations in the courtyard and they are compared to experimental measurements. ITS also calculates the photons and electrons that are injected into the courtyard, these quantities are then used by EMPIRE to calculated the photon and electron transport in the courtyard. The details for the algorithms used to perform the courtyard simulations are presented as well as qualitative comparisons of the electric field, magnetic field, and the conductivity in the courtyard. Because of the computational burden of these calculations the pressure was reduce in the courtyard to reduce the computational load. The computation performance is presented along with suggestion on how to improve both the computational performance as well as the algorithmic performance. Some of the algorithmic changed would reduce the accuracy of the models and detail comparison of these changes are left for a future study. As well as, list of code improvements there is also a list of suggested experimental improvements to improve the quality of the data return.

Physics of Plasmas

Roberds, Nicholas R.; Cartwright, Keith C.; Sandoval, Andrew J.; Beckwith, Kristian B.; Cyr, Eric C.; Glines, Forrest W.

An approach to numerically modeling relativistic magnetrons, in which the electrons are represented with a relativistic fluid, is described. A principal effect in the operation of a magnetron is space-charge-limited (SCL) emission of electrons from the cathode. We have developed an approximate SCL emission boundary condition for the fluid electron model. This boundary condition prescribes the flux of electrons as a function of the normal component of the electric field on the boundary. We show the results of a benchmarking activity that applies the fluid SCL boundary condition to the one-dimensional Child–Langmuir diode problem and a canonical two-dimensional diode problem. Simulation results for a two-dimensional A6 magnetron are then presented. Computed bunching of the electron cloud occurs and coincides with significant microwave power generation. Numerical convergence of the solution is considered. Sharp gradients in the solution quantities at the diocotron resonance, spanning an interval of three to four grid cells in the most well-resolved case, are present and likely affect convergence.

Szalek, Nicolas S.; Gardelle, Jacques G.; Grua, Pierre G.; Hebert, David H.; Moore, Christopher H.; Medina, Brandon M.; Swan, Matthew S.; Cartwright, Keith C.

Abstract not provided.

Swan, Matthew S.; Sirajuddin, David S.; Cartwright, Keith C.; Moore, Christopher H.

Abstract not provided.

Medina, Brandon M.; Moore, Christopher H.; Bell, Kate S.; Bettencourt, Matthew T.; Cartwright, Keith C.; B., Cassany B.; D., Hebert D.; J., Gardelle J.; P., Modin P.; N., Szalek N.

Abstract not provided.

Miller, Sean M.; Cyr, Eric C.; Phillips, Edward G.; Pawlowski, Roger P.; Beckwith, Kristian B.; Bettencourt, Matthew T.; Cartwright, Keith C.; Shields, Sidney S.

Abstract not provided.

Cyr, Eric C.; Miller, Sean M.; Pawlowski, Roger P.; Phillips, Edward G.; Beckwith, Kristian B.; Bettencourt, Matthew T.; Cartwright, Keith C.; Kramer, Richard M.; Roberts, Nathan V.; Shadid, John N.; Shields, Sidney S.

Abstract not provided.

Shields, Sidney S.; Cartwright, Keith C.; Miller, Sean M.; Pointon, Timothy D.; Cyr, Eric C.; Beckwith, Kristian B.

Abstract not provided.

Medina, Brandon M.; Moore, Christopher H.; Bettencourt, Matthew T.; Cartwright, Keith C.; Powell, Troy C.; Pointon, Timothy D.; Phillips, Edward G.; Bell, Kate S.; Gardelle, J.G.; Cassany, B.C.; Modin, P.M.; Szalek, N.S.; Hebert, D.H.

Abstract not provided.

Cartwright, Keith C.; Moore, Christopher H.; Roberds, Nicholas R.; Abel, Kelsey C.; Flanagan, Timothy M.; Christenson, Peggy J.; Bettencourt, Matthew T.; Pointon, Timothy D.; Turner, C.D.; Raybourn, Elaine M.

Abstract not provided.

Cyr, Eric C.; Miller, Sean M.; Phillips, Edward G.; Beckwith, Kristian B.; Bettencourt, Matthew T.; Cartwright, Keith C.; Kramer, Richard M.; Pawlowski, Roger P.; Roberts, Nathan V.; Shadid, John N.; Shields, Sidney S.

Abstract not provided.

Shields, Sidney S.; Cartwright, Keith C.; Pointon, Timothy D.; Cyr, Eric C.; Beckwith, Kristian B.

Abstract not provided.

Roberds, Nicholas R.; Bettencourt, Matthew T.; Cartwright, Keith C.; Moore, Christopher H.

Abstract not provided.

McDoniel, William M.; Moore, Christopher H.; Radtke, Gregg A.; Cartwright, Keith C.; Bettencourt, Matthew T.

Abstract not provided.

Roberds, Nicholas R.; Bettencourt, Matthew T.; Cartwright, Keith C.; Moore, Christopher H.

Abstract not provided.

Medina, Brandon M.; Moore, Christopher H.; Bettencourt, Matthew T.; Cartwright, Keith C.; Powell, Troy C.; Pointon, Timothy D.; Phillips, Edward G.; Bell, Kate S.; Gardelle, J.G.; Cassany, B.C.; Modin, P.M.; Szalek, N.S.; Hebert, D.H.

Abstract not provided.

Bettencourt, Matthew T.; Shields, Sidney S.; Beckwith, Kristian B.; Cartwright, Keith C.; Cyr, Eric C.; Kramer, Richard M.; Lin, Paul L.; McDoniel, William M.; Miller, Sean M.; Pawlowski, Roger P.; Phillips, Edward G.; Roberts, Nathan V.

Abstract not provided.

Cartwright, Keith C.; Bettencourt, Matthew T.; Pointon, Timothy D.; Beckwith, Kristian B.; Cyr, Eric C.; Kramer, Richard M.; McDoniel, William M.; Miller, Sean M.; Radtke, Gregg A.; Shields, Sidney S.; Swan, Matthew S.; Turner, C.D.; Moore, Christopher H.

Abstract not provided.

Moore, Christopher H.; Medina, Brandon M.; Cartwright, Keith C.; Bettencourt, Matthew T.; Hopkins, Matthew M.; Yee, Benjamin T.; Bell, Kate S.

Abstract not provided.

Cartwright, Keith C.; Christenson, Peggy J.; Powell, Troy C.; Pointon, Timothy D.; Phillips, Edward G.

Abstract not provided.

Medina, Brandon M.; Moore, Christopher H.; Bettencourt, Matthew T.; Cartwright, Keith C.; Pointon, Timothy D.; Phillips, Edward G.; Bell, Kate S.; Gardelle, Jacques G.; Hebert, David H.

Abstract not provided.

Cyr, Eric C.; Beckwith, Kristian B.; Bettencourt, Matthew T.; Cartwright, Keith C.; Kramer, Richard M.; Miller, Sean T.; Pawlowski, Roger P.; Phillips, Edward G.; Roberts, Nathan V.; Shadid, John N.

Abstract not provided.

Bettencourt, Matthew T.; Kramer, Richard M.; Cartwright, Keith C.; Phillips, Edward G.; Ober, Curtis C.; Pawlowski, Roger P.; Swan, Matthew S.; Kalashnikova, Irina; Phipps, Eric T.; Conde, Sidafa C.; Cyr, Eric C.; Ulmer, Craig D.; Kordenbrock, Todd H.; Levy, Scott L.; Templet, Gary J.; Hu, Jonathan J.; Lin, Paul L.; Glusa, Christian A.; Siefert, Christopher S.; Glass, Micheal W.

This report documents the outcome from the ASC ATDM Level 2 Milestone 6358: Assess Status of Next Generation Components and Physics Models in EMPIRE. This Milestone is an assessment of the EMPIRE (ElectroMagnetic Plasma In Realistic Environments) application and three software components. The assessment focuses on the electromagnetic and electrostatic particle-in-cell solu- tions for EMPIRE and its associated solver, time integration, and checkpoint-restart components. This information provides a clear understanding of the current status of the EMPIRE application and will help to guide future work in FY19 in order to ready the application for the ASC ATDM L 1 Milestone in FY20. It is clear from this assessment that performance of the linear solver will have to be a focus in FY19.

Cartwright, Keith C.; Christenson, Peggy J.; Powell, Troy C.; Reynolds, James M.; Pointon, Timothy D.; Phillips, Edward G.

Abstract not provided.