Visible to the public Biblio

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2023-05-12
Chen, C., Becker, J. R., Farrell, J. J..  2022.  Energy Confinement Time in a Magnetically Confined Thermonuclear Fusion Reactor. 2022 IEEE International Conference on Plasma Science (ICOPS). :1–1.
The single most important scientific question in fusion research may be confinement in a fusion plasma [1] . A recently-developed theoretical model [2] is reviewed for the confinement time of ion kinetic energy in a material where fusion reactions occur. In the theoretical model where ion stopping was considered as a key mechanism for ion kinetic energy loss, an estimate was obtained for the confinement time of ion kinetic energy in a D-T plasma - and found to be orders of magnitude lower than required in the Lawson criterion. As ions transfer their kinetic energies to electrons via ion stopping and thermalization between the ions and the electrons takes place, spontaneous electron cyclotron radiation is identified as a key mechanism for electron kinetic energy loss in a magnetically confined plasma. The energy confinement time is obtained and found in agreement with measurements from TFTR [1] and Wendelstein 7-X [3] . An advanced Lawson criterion is obtained for a magnetically confined thermonuclear fusion reactor.
ISSN: 2576-7208
2023-01-13
Masago, Hitoshi, Nodaka, Hiro, Kishimoto, Kazuma, Kawai, Alaric Yohei, Shoji, Shuichi, Mizuno, Jun.  2022.  Nano-Artifact Metrics Chip Mounting Technology for Edge AI Device Security. 2022 17th International Microsystems, Packaging, Assembly and Circuits Technology Conference (IMPACT). :1—4.
In this study, the effect of surface treatment on the boding strength between Quad flat package (QFP) and quartz was investigated for establishing a QFP/quartz glass bonding technique. This bonding technique is necessary to prevent bond failure at the nano-artifact metrics (NAM) chip and adhesive interface against physical attacks such as counterfeiting and tampering of edge AI devices that use NAM chips. Therefore, we investigated the relationship between surface roughness and tensile strength by applying surface treatments such as vacuum ultraviolet (VUV) and Ar/O2 plasma. All QFP/quartz glass with surface treatments such as VUV and Ar/O2 plasma showed increased bond strength. Surface treatment and bonding technology for QFP and quartz glass were established to realize NAM chip mounting.
2022-08-26
Gomez, Matthew R., Slutz, S.A., Jennings, C.A., Weis, M.R., Lamppa, D.C., Harvey-Thompson, A.J., Geissel, M., Awe, T.J., Chandler, G.A., Crabtree, J.A. et al..  2021.  Developing a Platform to Enable Parameter Scaling Studies in Magnetized Liner Inertial Fusion Experiments. 2021 IEEE International Conference on Plasma Science (ICOPS). :1—1.
Magnetized Liner Inertial Fusion (MagLIF) is a magneto-inertial fusion concept that relies on fuel magnetization, laser preheat, and a magnetically driven implosion to produce fusion conditions. In MagLIF, the target is a roughly 10 mm long, 5 mm diameter, 0.5 mm thick, cylindrical beryllium shell containing 1 mg/cm 3 D 2 gas. An axial magnetic field on the order of 10 T is applied to the target, and several kJ of laser energy is deposited into the fuel. Up to 20 MA of current is driven axially through the beryllium target, causing it to implode over approximately 100 ns. The implosion produces a 100-μm diameter, 8-mm tall fuel column with a burn-averaged ion temperature of several keV, that generates 10 11 -10 13 DD neutrons.
Shipley, G. A., Awe, T. J., Jennings, C. A., Hutsel, B. T..  2021.  Three-Dimensional Magnetohydrodynamic Modeling of Auto-Magnetizing Liner Implosions. 2021 IEEE International Conference on Plasma Science (ICOPS). :1—1.
Auto-magnetizing (AutoMag) liners 1 have demonstrated strong precompressed axial magnetic field production (\textbackslashtextgreater100 T) and remarkable cylindrical implosion uniformity during experiments 2 on the Z accelerator. However, both axial field production and implosion uniformity require further optimization to support use of AutoMag targets in magnetized liner inertial fusion (MagLIF) experiments. Recent experimental study on the Mykonos accelerator has provided data on the initiation and evolution of dielectric flashover in AutoMag targets; these results have directly enabled advancement of magnetohydrodynamic (MHD) modeling protocols used to simulate AutoMag liner implosions. Using these modeling protocols, we executed three-dimensional MHD simulations focused on improving AutoMag target designs, specifically seeking to optimize axial magnetic field production and enhance cylindrical implosion uniformity for MagLIF. By eliminating the previously used driver current prepulse and reducing the helical gap widths in AutoMag liners, simulations indicate that the optimal 30-50 T range of precompressed axial magnetic field for MagLIF can be accomplished concurrently with improved cylindrical implosion uniformity, thereby enabling an optimally premagnetized magneto-inertial fusion implosion with high cylindrical uniformity.
Gomez, Matthew R., Myers, C.E., Hatch, M.W., Hutsel, B.T., Jennings, C.A., Lamppa, D.C., Lowinske, M.C., Maurer, A.J., Steiner, A.M., Tomlinson, K. et al..  2021.  Developing An Extended Convolute Post To Drive An X-Pinch For Radiography At The Z Facility. 2021 IEEE International Conference on Plasma Science (ICOPS). :1—1.
X-ray radiography has been used to diagnose a wide variety of experiments at the Z facility including inertial confinement fusion capsule implosions, the growth of the magneto-Rayleigh-Taylor instability in solid liners, and the development of helical structures in axially magnetized liner implosions. In these experiments, the Z Beamlet laser (1 kJ, 1 ns) was used to generate the x-ray source. An alternate x-ray source is desirable in experiments where the Z Beamlet laser is used for another purpose (e.g., preheating the fuel in magnetized liner inertial fusion experiments) or when multiple radiographic lines of sight are necessary.
Lewis, William E., Knapp, Patrick F., Slutz, Stephen A., Schmit, Paul F., Chandler, Gordon A., Gomez, Matthew R., Harvey-Thompson, Adam J., Mangan, Michael A., Ampleford, David J., Beckwith, Kristian.  2021.  Deep Learning Enabled Assessment of Magnetic Confinement in Magnetized Liner Inertial Fusion. 2021 IEEE International Conference on Plasma Science (ICOPS). :1—1.
Magnetized Liner Inertial Fusion (MagLIF) is a magneto-inertial fusion (MIF) concept being studied on the Z-machine at Sandia National Laboratories. MagLIF relies on quasi-adiabatic heating of a gaseous deuterium (DD) fuel and flux compression of a background axially oriented magnetic field to achieve fusion relevant plasma conditions. The magnetic flux per fuel radial extent determines the confinement of charged fusion products and is thus of fundamental interest in understanding MagLIF performance. It was recently shown that secondary DT neutron spectra and yields are sensitive to the magnetic field conditions within the fuel, and thus provide a means by which to characterize the magnetic confinement properties of the fuel. 1 , 2 , 3 We utilize an artificial neural network to surrogate the physics model of Refs. [1] , [2] , enabling Bayesian inference of the magnetic confinement parameter for a series of MagLIF experiments that systematically vary the laser preheat energy deposited in the target. This constitutes the first ever systematic experimental study of the magnetic confinement properties as a function of fundamental inputs on any neutron-producing MIF platform. We demonstrate that the fuel magnetization decreases with deposited preheat energy in a fashion consistent with Nernst advection of the magnetic field out of the hot fuel and diffusion into the target liner.
2020-11-04
Peruma, A., Malachowsky, S., Krutz, D..  2018.  Providing an Experiential Cybersecurity Learning Experience through Mobile Security Labs. 2018 IEEE/ACM 1st International Workshop on Security Awareness from Design to Deployment (SEAD). :51—54.

The reality of today's computing landscape already suffers from a shortage of cybersecurity professionals, and this gap only expected to grow. We need to generate interest in this STEM topic early in our student's careers and provide teachers the resources they need to succeed in addressing this gap. To address this shortfall we present Practical LAbs in Security for Mobile Applications (PLASMA), a public set of educational security labs to enable instruction in creation of secure Android apps. These labs include example vulnerable applications, information about each vulnerability, steps for how to repair the vulnerabilities, and information about how to confirm that the vulnerability has been properly repaired. Our goal is for instructors to use these activities in their mobile, security, and general computing courses ranging from secondary school to university settings. Another goal of this project is to foster interest in security and computing through demonstrating its importance. Initial feedback demonstrates the labs' positive effects in enhancing student interest in cybersecurity and acclaim from instructors. All project activities may be found on the project website: http://www.TeachingMobileSecurity.com