Atomistic Simulations of Displacement Cascades in Fused Silica: It is Compared with Different Concentration of H in the Bulk

2006 ◽  
Vol 981 ◽  
Author(s):  
Fernando Mota ◽  
Maria Jose Caturla ◽  
Jose Manuel Perlado ◽  
Angel Ibarra ◽  
Joaquin Molla
Keyword(s):  
Control Systems ◽  
Amorphous Silica ◽  
Fused Silica ◽  
Atomistic Simulations ◽  
Inertial Fusion ◽  
Fusion Reactors ◽  
Magnetic Fusion ◽  
Hydrogen Atoms ◽  
And Control ◽  
High Neutron

AbstractAmorphous Silica is one of candidate materials for both final focusing optics of lasers for NIF and future inertial fusion reactors and diagnostics of the Safety and Control Systems of the ITER machine as well as DEMO magnetic fusion reactors. In operation, these materials will be exposed to high neutron irradiation fluxes and it can result in point defect and vary the optical absorption, that is, degradation of the optical properties. In this paper we present molecular dynamic simulation of displacement cascade due to energetic recoils in amorphous silica without hydrogen atoms and with 1% of hydrogen atoms trying to identify defects formation. We have made a statistics of the different kind of defects at different energy of primary knock-on atoms (PKA). The range of studied PKA energies are from 400 eV to 3.5 keV and it is made to both component of this material Silicon and Oxygen.

Atomistic simulations of threshold displacement energies in SiO2

2003 ◽  
Vol 792 ◽  
Author(s):  
F. Mota ◽  
M.-J. Caturla ◽  
J.M. Perlado ◽  
E. Dominguez ◽  
A. Kubota
Keyword(s):  
Point Defects ◽  
Original Position ◽  
Atomistic Simulations ◽  
Inertial Fusion ◽  
Fusion Reactors ◽  
Molecular Dynamic Simulations ◽  
Defect Production ◽  
Dynamic Simulations ◽  
Threshold Displacement ◽  
High Neutron

ABSTRACTSilica is one of the candidate materials for final focusing mirrors in inertial fusion reactors. This material will be exposed to high neutron irradiation fluxes during operation. Radiation damage results in point defects that can lead to obscuration of this material; that is, degradation of the optical properties of silica. In this paper we present molecular dynamic simulations of defect production in silica glass. Results on the threshold displacement energies due to oxygen Primary Knock-on Atoms (PKA) are reported concluding that a range of energies (20–40 eV) exists in which the defects have a probability to be created. In addition, we determine a range of distances for a PKA to become a stable defect out of its original position. Our present analysis is focused on the formation of Oxygen Deficient Centers (ODC).

Artificial Hair Sensors: Electro-Mechanical Characterization

2014 ◽  
Author(s):  
David M. Phillips ◽  
Keith A. Slinker ◽  
Cody W. Ray ◽  
Benjamin J. Hagen ◽  
Jeffery W. Baur ◽  
...  
Keyword(s):  
Control Systems ◽  
Flight Control ◽  
Mechanical Characterization ◽  
Glass Fibers ◽  
Fused Silica ◽  
Control Algorithms ◽  
Resistance Change ◽  
Micron Diameter ◽  
And Control ◽  
Hair Sensors

Performance demands of future unmanned air vehicles will require rapid autonomous responses to changes in environment. Towards this goal, we expect that the next generation flight control systems will include advanced sensors beyond the contemporary array. One promising scenario correlates measurements of flow footprints over aircraft surfaces with aerodynamic data to aid navigation and feedback control algorithms. As a sensor for this concept, we construct artificial hair sensors (AHSs) based on glass microfibers enveloped in an annular, radially-aligned piezoresistive carbon nanotube (CNT) forest to measure air flow in boundary layers. This study includes an analysis of the sensitivity based on laboratory scale electromechanical testing. The sensors in this work utilize nine micron diameter S2 glass fibers as the sensing mechanism for coupling to boundary layer air flows. The annular CNT forest resides in a fused silica microcapillary with electrodes at the entrance. The sensor electrical transduction mechanism relies on the resistance change of the CNT forest due to changes in both the bulk and contact resistance as a function of mechanical loading on the fiber. For the electromechanical analysis, the sensors are controllably loaded to measure both the force and moment acting at the base of the hair and the resulting deflection of the CNT forest inside of the microcapillary is measured to estimate the stress on the forest and the pressure between the forest and the electrode. The electrical responses of the sensors are compared to the mechanical state of the CNT forest. This work represents the development of a characterization tool to better understand and control the response of CNT based AHSs.

Radiation damage in metals, and amorphous silica in inertial fusion reactors: Modeling and experiments

2006 ◽  
Vol 133 ◽  
pp. 805-809 ◽  
Author(s):  
J. M. Perlado ◽  
M. Victoria ◽  
M. J. Caturla ◽  
J. Marian ◽  
M. L. Gámez ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Amorphous Silica ◽  
Inertial Fusion ◽  
Fusion Reactors ◽  
Modeling And Experiments

Probability model for control parameters in the aircraft's information and control systems

2018 ◽  
Vol 2 ◽  
pp. 9-16
Author(s):  
A. Al-Ammouri ◽  
◽  
H.A. Al-Ammori ◽  
A.E. Klochan ◽  
A.M. Al-Akhmad ◽  
...  
Keyword(s):  
Control Systems ◽  
Probability Model ◽  
Control Parameters ◽  
And Control

A Proposal of Ajax Framework for Web-based Supervisory and Control Systems

2010 ◽  
Vol 130 (12) ◽  
pp. 2276-2285
Author(s):  
Shintaro Yanagihara ◽  
Akira Ishihara ◽  
Toshinao Ishii ◽  
Junichi Kitsuki ◽  
Kazuo Seo
Keyword(s):  
Control Systems ◽  
Web Based ◽  
And Control ◽  
Ajax Framework
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