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Transient electromagnetic analysis of blanket modules 14 and 15 in different sectors of the ITER blanket system due to plasma disruption

Fusion Science and Technology

Kotulski, J.D.; Coats, Rebecca S.

The ITER blanket system provides shielding of the plasma controlling field coils and vacuum vessel from the plasma heat flux as well as nuclear heating from the plasma. In addition to the thermal requirements the blanket module attachment scheme must withstand the electromagnetic forces that occur during possible plasma disruption events. During a plasma disruption event eddy currents are induced in the blanket module (first wall and shield block) and interact with the large magnetic fields to produce forces which could potentially cause mechanical failure. For this reason the design and qualification of the ITER blanket system requires appropriate high-fidelity electromagnetic simulations that capture the physics of these disruption scenarios. The key features of the analysis procedure will be described including the modeling of the geometry of the blanket modules and the plasma current during disruption. The electromagnetic calculations are performed using the Opera-3d software. This software solves the transient 3D finite element problem from which the eddy currents are calculated. The electromagnetic loads due to these eddy currents are then calculated and translated to the local coordinate system of the blanket module of interest.

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Time harmonic two-dimensional cavity scar statistics: Convex mirrors and bowtie

Electromagnetics

Warne, Larry K.; Jorgenson, Roy E.; Kotulski, J.D.; Lee, K.S.H.

This article examines the localization of time harmonic high-frequency modal fields in two-dimensional cavities along periodic paths between opposing sides of the cavity. The cases where these orbits lead to unstable localized modes are known as scars. This article examines the enhancements for these unstable orbits when the opposing mirrors are convex, constructing the high-frequency field in the scar region using elliptic cylinder coordinates in combination with a random reflection phase from the outer chaotic region. The enhancements when the cavity is symmetric as well as asymmetric about the orbit are examined. © Taylor & Francis Group, LLC.

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Intelligent front-end sample preparation tool using acoustic streaming

Vreeland, Erika C.; Smith, Gennifer T.; Edwards, Thayne L.; James, Conrad D.; McClain, Jaime L.; Murton, Jaclyn K.; Kotulski, J.D.; Clem, Paul G.

We have successfully developed a nucleic acid extraction system based on a microacoustic lysis array coupled to an integrated nucleic acid extraction system all on a single cartridge. The microacoustic lysing array is based on 36{sup o} Y cut lithium niobate, which couples bulk acoustic waves (BAW) into the microchannels. The microchannels were fabricated using Mylar laminates and fused silica to form acoustic-fluidic interface cartridges. The transducer array consists of four active elements directed for cell lysis and one optional BAW element for mixing on the cartridge. The lysis system was modeled using one dimensional (1D) transmission line and two dimensional (2D) FEM models. For input powers required to lyse cells, the flow rate dictated the temperature change across the lysing region. From the computational models, a flow rate of 10 {micro}L/min produced a temperature rise of 23.2 C and only 6.7 C when flowing at 60 {micro}L/min. The measured temperature changes were 5 C less than the model. The computational models also permitted optimization of the acoustic coupling to the microchannel region and revealed the potential impact of thermal effects if not controlled. Using E. coli, we achieved a lysing efficacy of 49.9 {+-} 29.92 % based on a cell viability assay with a 757.2 % increase in ATP release within 20 seconds of acoustic exposure. A bench-top lysing system required 15-20 minutes operating up to 58 Watts to achieve the same level of cell lysis. We demonstrate that active mixing on the cartridge was critical to maximize binding and release of nucleic acid to the magnetic beads. Using a sol-gel silica bead matrix filled microchannel the extraction efficacy was 40%. The cartridge based magnetic bead system had an extraction efficiency of 19.2%. For an electric field based method that used Nafion films, a nucleic acid extraction efficiency of 66.3 % was achieved at 6 volts DC. For the flow rates we tested (10-50 {micro}L/min), the nucleic acid extraction time was 5-10 minutes for a volume of 50 {micro}L. Moreover, a unique feature of this technology is the ability to replace the cartridges for subsequent nucleic acid extractions.

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Results 26–50 of 60
Results 26–50 of 60