Mechanical and Electrical Properties of a CFETR CSMC Conductor under Transverse Mechanical Loadings

The central solenoid model coil (CSMC) project of the China Fusion Engineering Test Reactor was launched in 2014 to verify the technological feasibility of a large-scale superconducting magnet at the Institute of Plasma and Physics Chinese Academy of Sciences. The short twist pitch design recommended by CEA is chosen for the CSMC Nb3Sn cable-in-conduit conductors. In order to better understand the evolution of transport properties and coupling losses related to the effect of electromagnetic load cycles, the mechanical and electrical properties were measured and investigated employing a special cryogenic press facility for the transverse mechanical loadings. The results show that the transverse compression (dy) versus applied load force (Fy ) is different from first to subsequent loading cycles. This mechanical behavior can be interpreted by the combination of strands bending between the crossovers and strands deformation at the crossovers. The fitting relations of dy versus Fy are also presented. The evolution of interstrand contact resistance (Rc) in the cabling stages with cyclic history and pressure effects are discussed. In addition, a fitting relation of Rc versus Fy is presented based on a combination of strand's microsliding and copper matrix resistivity. A clear correlation between intrapetal resistance Rc and coupling loss is also found

Lower Jurassic conodonts from the Inuyama area of Japan: implications for conodont extinction

It is generally accepted that conodonts went extinct at the end of the Triassic, but younger conodont fossils have been reported, and it is becoming clear that conodont extinction occurred asynchronously across different regions. Although some reports of post-Triassic conodonts have been disproven, Lower Jurassic conodonts have been found in the Buda area of Hungary and the Inuyama area of Japan. Here, we report the discovery of more conodonts Misikella posthernsteini above the first occurrence of the typical Jurassic radiolarian Pantanellium tanuense, which is not know from the Triassic, in the Kastuyama section, Inuyama area, reaffirming the authenticity of the Lower Jurassic conodonts. The conodonts survived into the Jurassic in the Inuyama area might be due to their remote locations relative to the Central Atlantic Magmatic Province, which buffered them from hypoxia and ocean acidification. Although conodont survived into the Lower Jurassic, they failed to recover and quickly went extinct in post-extinction ecosystems. The “dead clades walking” (DCWs) of conodont may have been due to protracted ocean acidification in the earliest Jurassic. Food scarcity and competition with other organisms may have led to the eventual extinction of conodonts

Carbon-isotope excursions in the Norian Stage (Upper Triassic) of the Baoshan terrane, western Yunnan, China

The biostratigraphy and carbon stable isotopes of the Norian Stage (Upper Triassic) are well studied in the western Tethys, but little information is available from the eastern Tethys. Therefore, we studied the Hongyan-B (HYB) section in the Baoshan terrane, western Yunnan Province, SW China, which was located in the eastern Tethys during the Late Triassic. The HYB section was investigated for conodonts, radiolarians, total organic carbon, carbonate carbon and oxygen stable isotopes (delta C-13(carb) and delta O-18(carb)), and carbon isotopes of organic matter (delta C-13(org)). The Mockina slovakensis and Mockina bidentata conodont biozones proposed in the HYB section are associated with two radiolarian zones of the Sevatian substage, the Praemesosaturnalis multidentatus and Praemesosaturnalis pseudokahleri zones (TR8A and TR8B Sugiyama zones). This biostratigraphy places the Alaunian-Sevatian substage boundary (middle-upper Norian) at meter 23 of the HYB section. Unfortunately, the delta C-13(carb) and delta O-18(carb) values suggest that they might have been influenced by diagenesis. However, the delta C-13(org) record preserves multiple carbon-isotope excursions across the Alaunian-Sevatian boundary that can be correlated with other coeval global sections. The carbon-isotope excursions registered at this middle-upper Norian boundary are perhaps related to the major outgassing of light carbon during the emplacement of Angayucham flood basalts

Performance of the Cable-in-Conduit Conductors for Super-X Test Facility

Following the conceptual design, the engineering design of the dc magnet and cable-in-conduit conductor (CICC) for the Super-X test facility has been done in 2021. Totally three types of conductors with different structures were designed for the three pairs of coils in the dc magnet, respectively. High- Jc Nb 3 Sn strand (J c ∼2200 A/mm 2 at 12 T, 4.2 K) was applied to high field and middle field coils for reducing the radius of the dc magnet. In order to qualify if the designed parameters of the conductors could fulfill the performance criteria, three pairs of short samples have been manufactured and tested successfully in the SULTAN facility at SPC, Switzerland. Test results and analysis show that dc performance of the three types of conductors can meet the design criteria. The conductor qualification process including the sample preparation, test results, and analysis are presented in this article. The HFC and LFC conductors exhibit different ac loss behavior to the MFC conductor, which is discussed in the article

Unveiling a new oceanic anoxic event at the Norian/Rhaetian boundary (Late Triassic)

Abstract The latest Triassic was characterised by protracted biotic extinctions concluding in the End-Triassic Extinction (~ 200 Ma) and a global carbon cycle perturbation. The onset of declining diversity is closely related to reducing conditions that spread globally from upper Sevatian (uppermost Norian) to across the Norian-Rhaetian boundary, likely triggered by unusually high volcanic activity. We correlate significant organic carbon cycle perturbations to an increase of CO2 in the ocean–atmosphere system, likely outgassed by the Angayucham igneous province, the onset of which is indicated by the initiation of a rapid decline in 87Sr/86Sr and 188Os/187Os seawater values. A possible causal mechanism involves elevated CO2 levels causing global warming and accelerating chemical weathering, which increased nutrient discharge to the oceans and greatly increased biological productivity. Higher export production and oxidation of organic matter led to a global O2 decrease in marine water across the Norian/Rhaetian boundary (NRB). Biotic consequences of dysoxia/anoxia include worldwide extinctions in some fossil groups, such as bivalves, ammonoids, conodonts, radiolarians