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The Mission of the Robotics and Remote Systems Division is to promote the development and application of immersive simulation, robotics, and remote systems for hazardous environments for the purpose of reducing hazardous exposure to individuals, reducing environmental hazards and reducing the cost of performing work.
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2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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Fusion Science and Technology
Latest News
Commercial nuclear innovation "new space" age
In early 2006, a start-up company launched a small rocket from a tiny island in the Pacific. It exploded, showering the island with debris. A year later, a second launch attempt sent a rocket to space but failed to make orbit, burning up in the atmosphere. Another year brought a third attempt—and a third failure. The following month, in September 2008, the company used the last of its funds to launch a fourth rocket. It reached orbit, making history as the first privately funded liquid-fueled rocket to do so.
Shouhua Sun, Jingyi Shi, Liuliu Li, Lei Peng
Fusion Science and Technology | Volume 78 | Number 2 | February 2022 | Pages 134-148
Technical Paper | doi.org/10.1080/15361055.2021.1962120
Articles are hosted by Taylor and Francis Online.
Helium produced by neutron irradiation is a crucial inducement to bring about the property of deterioration of structural materials served in a fusion reactor. To investigate the nucleation and growth behavior of helium bubbles in reduced activation ferritic/martensitic steels, which comprise one of the most promising candidate structural materials, the Molecular Statics method and the Metropolis Monte Carlo algorithm are combined to investigate the energetic and mechanical behaviors of HenVm clusters in α-Fe. The simulation results show that the vacancy and helium atom binding energy are inclined to reach a saturation state, i.e., 4.0 eV for the vacancy and 2.4 eV for the helium atom; however, the binding energy of self-interstitial atoms decreases to minus values at high helium-to-vacancy (He/V) ratios. The crossover of the binding energy curve of the helium and vacancy indicates that the equilibrium He/V ratio is 1.68 during the nucleation of helium bubbles. Meanwhile, the dissociation energy analysis indicates that the stable He/V ratio of the clusters is 1.3 at high temperatures. Moreover, the pressure analysis of the HenVm clusters indicates that the He/V ratio corresponding to their mechanical equilibrium state varies from 0.50 to 0.65 at 0 K. Furthermore, the analysis combined with the relevant experimental data of helium density in helium bubbles indicates that the actual He/V ratio of helium bubbles in the served materials is closely relevant to the irradiation condition, such as helium production rate, temperature, etc. The investigation results in this paper contribute to elucidate the microscopic process of helium bubble nucleation and growth and provides the energetic and mechanical parameters of small-sized helium bubbles with different sizes for large-scale simulation studies.