As the most noticeable plasma-oriented material (PFM), metal tungsten is widely used in nuclear fusion reactors. However, its oxidation resistance is poor at high temperatures. When the reactor loss ...of cooling accident occurs, tungsten armor is oxidized and volatilized rapidly due to air enters the vacuum chamber, which will cause catastrophic nuclear leakage accidents. Relevant scholars have conducted a large number of studies, pointed out that the developments of self-passivating tungsten alloy and surface protection technology are effective ways to solve this problem. In this work, the application of various alloys and coatings in the oxidation protection of tungsten is reviewed, and their microstructure, oxidation behavior, and failure mechanism are analyzed and summarized. The development direction and trend of oxidation protection of W-based materials are prospected.
We have studied the sup.54-60Fe-induced fusion reactions to synthesize the superheavy nucleisup.296-302120 by studying the compound nucleus formation probability, survival probability, and ...evaporation residue cross-sections. The comparison of the evaporation residue cross-section for different targets reveals that the evaporation residue cross-section is larger for projectile target combination sup.58Fe+sup.243Puright arrowsup.301120. We have identified the most probable sup.58Fe-induced fusion reactions to synthesize superheavy nuclei sup.296-302120. The suggested reactions may be useful to synthesize the superheavy element Z = 120.
Detection of nuclear-decay γ rays provides a sensitive thermometer of nova nucleosynthesis. The most intense γ-ray flux is thought to be annihilation radiation from the β+ decay of 18F , which is ...destroyed prior to decay by the 18F(p, α) 15O reaction. Estimates of 18F production had been uncertain, however, because key near-threshold levels in the compound nucleus, 19Ne , had yet to be identified. We report the first measurement of the 19F(3He, tγ) 19Ne reaction, in which the placement of two long-sought 3/2+ levels is suggested via triton- γ−γ coincidences. The precise determination of their resonance energies reduces the upper limit of the rate by a factor of 1.5–17 at nova temperatures and reduces the average uncertainty on the nova detection probability by a factor of 2.1.
Neutron induced reactions on stable and unstable nuclei play a significant role in the nucleosynthesis of the elements in the cosmos. In the last years, several efforts have been made to investigate ...the possibility of applying the Trojan Horse Method (THM) to neutron induced reactions mostly by using deuteron as “TH-nucleus”. Here, the main advantages of using THM will be given together with a more focused discussion on the recent
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Be(n,
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He and the
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C reactions.
Nuclear fusion is one of the most attractive alternatives to carbon-dependent energy sources1. Harnessing energy from nuclear fusion in a large reactor scale, however, still presents many scientific ...challenges despite the many years of research and steady advances in magnetic confinement approaches. State-of-the-art magnetic fusion devices cannot yet achieve a sustainable fusion performance, which requires a high temperature above 100 million kelvin and sufficient control of instabilities to ensure steady-state operation on the order oftens of seconds2,3. Here we report experiments at the Korea Superconducting Tokamak Advanced Research4 device producing a plasma fusion regime that satisfies most ofthe above requirements: thanks to abundant fast ions stabilizing the core plasma turbulence, we generate plasmas at a temperature of 100 million kelvin lasting up to 20 seconds without plasma edge instabilities or impurity accumulation. A low plasma density combined with a moderate input power for operation is key to establishing this regime by preserving a high fraction of fast ions. This regime is rarely subject to disruption and can be sustained reliably even without a sophisticated control, and thus represents a promising path towards commercial fusion reactors.
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