ENN (China)

Boron (11B) pellet injection is designated as a routine fueling technique for the EHL-2 spherical torus. The predictive modeling of 11B pellet injection for H-mode plasma fueling in EHL-2 has been performed using the three-dimensional (3D) nonlinear magnetohydrodynamic (MHD) code JOREK. The simulation results show that the 11B pellet induces rapid local cooling and temperature profile contraction. This constrains the ablation rate to a relatively low level, enabling it to penetrate effectively through the pedestal region and reach the core up to a position of 0.35 in normalized poloidal flux. After the pellet is completely ablated, approximately 90% of the 11B is deposited inside the separatrix. The increased edge resistivity resulting from temperature contraction modifies the poloidal magnetic flux via Ampère’s law. This perturbs the toroidal current density near rational surfaces, enhances the radial gradient therein and drives multiple tearing modes. Interactions among high poloidal mode (high-m) edge magnetic islands lead to magnetic stochasticity, but the stochastic layer does not expand inward beyond the pedestal during injection. After complete ablation, the growth of tearing modes ceases, suggesting that pellet injection can deliver material deeply without triggering persistently growing MHD instabilities.

Toroidal eddy currents induced in the tokamak vacuum vessel play a critical role in plasma startup, volt-second consumption, and magnetic field configuration. However, the direct and accurate measurement of these currents is challenged by the presence of strong background magnetic fields—on the order of several Tesla—generated by the central solenoid (CS) and poloidal field (PF) coils, with currents often exceeding several mega-ampere-turns. This paper presents a novel dual-loop fiber optic current sensor (FOCS) system developed specifically for the EXL-50U spherical tokamak to directly measure toroidal eddy currents. The diagnostic setup includes an inner FOCS loop dedicated to measuring the plasma current (I p), and an outer loop for detecting the total enclosed toroidal current, which comprises contributions from the plasma, all external coils, and the eddy currents. A specially designed hardware compensation coil physically cancels the dominant magnetic flux generated by the CS leads in real time, significantly enhancing the signal-to-noise ratio. Experimental results demonstrate that the system is capable of measuring eddy currents even under strong background fields. The measured waveforms are in good agreement with numerical simulations, validating both the diagnostic approach and the electromagnetic model of the device. The proposed diagnostic system offers a robust and reliable tool for optimizing plasma startup scenarios in spherical tokamaks.

ObjectiveSymptomatic treatment for osteoarthritis (OA) remains a major unmet need. This trial evaluated XG005, a novel, non-opioid, dual-mechanism agent targeting both inflammatory and neuropathic pathways in patients with knee OA.DesignThis randomized, double-blind, placebo-controlled study enrolled 318 patients with moderate-to-severe knee OA pain to receive XG005 750 mg, 500 mg, or placebo twice daily for 4 weeks. Efficacy measures included weekly average of daily walking pain (WADWP), Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), Patient Global Impression of Change (PGIC), Sleep Interference Score (SIS), and Short-Form-12 Health Survey (SF-12).ResultsThe primary efficacy endpoint of improvement from baseline in WADWP at week 4 was statistically greater for the 750 mg group than placebo with least squares mean difference (LSMD) (95 % CI) of −0.55 (−0.94, −0.16). Key secondary endpoints were significantly improved for high- and low-dose XG005 compared to placebo at week 4, with LSMD (95 % CI) of −0.43 (−0.74, −0.13) and −0.4 (−0.78, −0.02) in WOMAC pain, and 5.56 (2.69, 8.42) and 3.74 (0.17, 7.31) in KOOS pain. WOMAC and KOOS stiffness and function, PGIC, SIS and SF-12 mental and general health showed statistically significant improvements over placebo. Patients with neuropathic pain had approximately 2-3-fold greater symptom improvements than patients with nociceptive pain. Mild dizziness and somnolence were most seen in XG005 groups.ConclusionXG005 demonstrated consistent efficacy in improving OA symptoms with acceptable tolerability. Additional studies in OA patients with neuropathic pain are needed to confirm its dual mechanism advantages.Clinical trial registrationCTR20222406.

BackgroundXeligekimab is a novel immunoglobulin G4 (IgG4) monoclonal antibody targeting interleukin-17A (IL-17A). In a phase III trial in patients with plaque psoriasis, xeligekimab showed efficacy and safety consistent with other IL-17A inhibitors, supporting its potential application in the treatment of spondyloarthritis.ObjectiveThis phase III trial aimed to investigate the efficacy and safety of xeligekimab in patients with radiographic axial spondyloarthritis (r-axSpA).MethodsThis was a phase III study conducted at multiple centers in China. Eligible patients were randomly assigned (1:1:1) to receive xeligekimab 100 mg, xeligekimab 200 mg, or placebo. Randomization was stratified by medication history (biologic-experienced vs. biologic-naïve) and weight (≥ 70 kg vs. < 70 kg). The primary endpoint was the proportion of patients achieving an Assessment of SpondyloArthritis International Society 20 (ASAS20) response at week 16. A key secondary endpoint was the ASAS40 response rate at the same time point.ResultsA total of 465 patients were recruited. A significantly higher proportion of patients receiving xeligekimab 200 mg (n = 114 (74.0%); p < 0.001, 95% confidence interval (CI) 28.5–48.4) and xeligekimab 100 mg (n = 102 (65.8%); p < 0.001, 95% CI 19.4–41.0) achieved an ASAS20 response compared to the placebo group (n = 56 (35.9%)) at week 16. Similarly, a significantly higher ASAS40 response rate was observed in the xeligekimab 100 mg group (n = 62 (40.0%); p < 0.001) and the xeligekimab 200 mg group (n = 64 (41.6%); p < 0.001) compared to placebo. Adverse events were similar across all groups, with serious adverse events occurring in 1.6% of the treatment group during the core treatment period. No unexpected safety signals were reported through week 48.ConclusionXeligekimab demonstrated significant efficacy in improving the signs and symptoms of active r-axSpA in Chinese patients at week 16, with sustained effects observed through week 48 and no new safety signals identified.Trial RegistrationClinicalTrials.gov identifier: NCT05881785 (Date: 21 May 2023).Supplementary InformationThe online version contains supplementary material available at 10.1007/s40259-025-00750-0.

A hard x-ray (HXR) spectrometer has been developed and implemented on the ENN Xuan-Long 50U (EXL-50U) spherical torus to study runaway electron (RE) dynamics. The diagnostic system features adjustable viewing geometries and optimized shielding designs, ensuring reliable operation under high-parameter plasma conditions. By utilizing LaBr3:Ce detectors with millisecond temporal resolution, both thin-target and thick-target bremsstrahlung spectra have been measured during plasma discharges. The system demonstrates the feasibility of investigating RE behavior through γ-ray spectroscopy in compact fusion devices, with potential applications in next-generation spherical torus.

Abstract In plasmas, bremsstrahlung includes electron–ion (e–i) bremsstrahlung and electron–electron (e–e) bremsstrahlung. Bremsstrahlung radiation power loss is one of the most significant losses in fusion plasmas, which is more pronounced in higher temperature fusion. The factors that affect bremsstrahlung power include the mean electron energy and the electron velocity distribution shape. In this study, we systematically study the influence of the electron velocity distribution shape on the bremsstrahlung power with fixed total electron energy. It was found that the existing electron velocity distribution shapes have little effect on the bremsstrahlung power. In addition, by analyzing the bounds of bremsstrahlung power, we have provided the theoretical upper and lower bounds of e–i radiation. Our analysis reveals that the e–i bremsstrahlung power depends critically on the degree of energy distribution concentration. Specifically, in non-relativistic regimes, concentrated energy distributions enhance the radiation power, whereas in high-temperature relativistic regimes, such concentration suppresses it. This discrepancy arises from the distinct contributions of high-energy electron populations to radiation power across different energy regimes. For e–e bremsstrahlung, a similar dependence on energy concentration is observed. Furthermore, e–e radiation power exhibits additional sensitivity to the anisotropy of the electron velocity distribution function. These rules could provide a basis for reducing bremsstrahlung power losses in fusion plasmas.

Abstract The development of shale gas reservoirs in China's Sichuan Basin faces multiple constraints, including dense surface obstacles, complex fault systems, and significant interference from existing wells. Conventional deployment methods suffer from poor multi-constraint coupling, high dependence on operator experience, and low iteration efficiency, making large-scale, efficient development difficult. This study proposes an intelligent horizontal well pattern deployment algorithm (iPlan) tailored for complex formations. The proposed approach consists of a three-stage workflow. First, multi-source data from a three-dimensional geological model are integrated to accurately characterize the subsurface complexity, while various input parameters enhance system flexibility. Second, a rapid economic benefit evaluation model is established, employing sensitivity analysis to quantitatively assess the nonlinear effects of input parameters on recovery factor and net present value, thereby delineating the key parameter feasible domain. Finally, a fusion strategy combining genetic algorithms and spatial topology is adopted for the optimal well pattern deployment search. Based on the existing geological model of the Sichuan shale gas field, the system extracted structural, property, and geomechanical data while acquiring obstacle information including faults, existing wells, and surface villages. An economic model was employed to determine the optimal length of horizontal section and well spacing. Through adaptive penalty functions, the system transformed the spatial constraints into a value-constrained plane for well pattern deployment optimization. By integrating the geological-engineering sweet spot of the target layer, a constrained sweet spot map for well pattern deployment was generated to guide the well pattern deployment in autonomously avoiding high-risk zones and prioritizing the coverage of high-value targets. The system successfully optimized the deployment of 198 horizontal wells within 40 minutes. The optimized well pattern effectively avoided interference from 76 faults and 44 existing wells, achieving a 21% increase in the well control area and 17% improvement in the expected internal rate of return (IRR). The findings indicate that the method significantly reduces reliance on manual expertise and accelerates the iterative process, achieving an efficiency nearly 100 times higher than conventional approaches. These findings confirm the proposed intelligent algorithm successfully resolves the optimization challenges arising from complex constraints, enabling efficient horizontal well pattern deployment.

Abstract Observations from the Parker Solar Probe have revealed the ubiquitous presence of right-handed polarized waves in the near-Sun solar wind. While antisunward fast-magnetosonic whistler waves have been commonly considered as their source, sunward ion cyclotron waves (ICWs) are another plausible candidate. Sunward ICWs can directly interact with antisunward ions via cyclotron resonant interactions, suggesting they may play an important role in particle energization processes in the solar wind. However, the generation of sunward ICWs remains poorly understood. In this study, we perform a theoretical instability survey over a broad parameter space to investigate the conditions that favor the generation of sunward ICWs, focusing on two key plasma properties: the temperature anisotropy and the relative streaming speed of the proton beam component. Our results show that sunward ICWs can be excited by proton beams with slow streaming speeds but significant temperature anisotropy. Additionally, the analysis reveals that the growth of this instability is strongly suppressed in environments with high alpha particle concentrations, indicating that sunward ICWs preferentially arise in plasmas with low alpha particle abundance. These findings offer new insights into the generation and nature of ion-scale waves in the near-Sun solar wind.