• Book : 10(1)
• Pub. Date : 2025
• Page : pp.101664
• Keyword :

Abstract

As magnetic confinement devices move toward higher fusion powers, moderating the heat load to the plasma-facing components becomes increasingly challenging. Efficient power dissipation can be achieved through control of the plasma radiation. However, defining a reliable proxy for the total radiated power is particularly challenging for non-axisymmetric devices such as stellarators. To address this problem, the radiated power can be estimated through a sum of the individual line-integrated bolometer measurements with weights properly calculated to account for the three-dimensional magnetic geometry. The present contribution aims to apply this weighted sum approach to Wendelstein 7-X (W7-X) and quantitatively validate it. First, we generate synthetic radiated power phantoms with characteristic W7-X radiation features to derive a set of optimized line-of-sight weights. Then, we test the weights on mock-ups and EMC3-EIRENE radiation patterns, including acquisition and analysis errors such as random noise fluctuations, camera misalignments, and field errors. Compared to other methods, the optimized weighted sum technique exhibited the best performance in all the presented synthetic test cases. When applied to experimental bolometer data, the optimized weights provided a proxy that is both reliable and real-time capable. Further validation is foreseen for the next experimental campaign.

• Book : 65(1)
• Pub. Date : 2025
• Page : pp.016035
• Keyword :

• Book : 43()
• Pub. Date : 2025
• Page : pp.100911
• Keyword :

Abstract

In indirect-drive inertial confinement fusion (ICF) research, the meticulous design and optimization of laser parameters are crucial for achieving high-gain ignition. The intensity of the toe laser, used for ablating the hohlraum sealing membrane, is a subtle but equally critical parameter. This study introduces a novel experimental approach using the Velocity Interferometer System for Any Reflector (VISAR) to assess the impact of toe laser intensity on the compression of fusion capsules. By tracking the reflectivity of tracer layers and shock velocities in liquid deuterium, the adverse effects of insufficient toe laser intensity on capsule compression have been unveiled for the first time. From a comparison with hydrodynamic simulations, we show that below a critical threshold of 0.23 × 10¹⁴ W cm⁻², the adiabat, a measure of the fuel’s compression efficiency, increases markedly with the toe laser intensity decreases, whereas it remains stable within the range of (0.23 ∼ 7) × 10¹⁴ W cm⁻². Our findings provide critical insights on toe laser parameter design, enhancing our understanding of the role of toe laser intensity in ICF experiments. This research not only refines the parameters for laser operation but also underscores the importance of precision in achieving the desired implosion efficiency, contributing to the development of nuclear fusion as a clean energy source.

• Book : 65(1)
• Pub. Date : 2025
• Page : pp.016032
• Keyword :

• Book : 212()
• Pub. Date : 2025
• Page : pp.111061
• Keyword :

• Book : 1070(p2)
• Pub. Date : 2025
• Page : pp.170020
• Keyword :

• Book : 1070(p1)
• Pub. Date : 2025
• Page : pp.170042
• Keyword :

• Book : 1070(p1)
• Pub. Date : 2025
• Page : pp.170031
• Keyword :

• Book : 1070(p1)
• Pub. Date : 2025
• Page : pp.170038
• Keyword :

• Book : 1071()
• Pub. Date : 2025
• Page : pp.170076
• Keyword :