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arXiv · 2603.11549

Design and mechanical analysis of the PRAGYA tokamak vacuum vessel

Ravi Gupta·Rahul Babu Koneru·Saptarshi Rajan Sarkar·Santosh Ansumali·Animesh Kuley·Roshan George·Shaurya Kaushal
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Abstract

PRAGYA is India's first privately developed low aspect ratio tokamak designed by Pranos Fusion Energy. The device is designed for a plasma major radius (R0) of about 0.4 m, a plasma minor radius (a) greater than 0.18 m, a plasma current (Ip) of up to 25 kA, and a toroidal magnetic field (B_T) of 0.1 T. The PRAGYA vacuum vessel incorporates several distinctive features, including a toroidal electrical break to minimize induced eddy currents and a double O-ring arrangement to reduce vacuum leakage. This paper presents the final design of the PRAGYA vacuum vessel and a comprehensive three-dimensional (3D) finite element model (FEM) assessment of its structural performance. The analysis evaluates the effects of self-weight, atmospheric pressure loading, and thermal stress arising from in-situ baking. The results confirm that the design satisfies the required safety margins under these combined loading conditions, providing a robust foundation for subsequent plasma operations in this compact tokamak.

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Ravi Gupta, Rahul Babu Koneru, Saptarshi Rajan Sarkar, Santosh Ansumali, Animesh Kuley, Roshan George, Shaurya Kaushal. 2026-03-12. Design and mechanical analysis of the PRAGYA tokamak vacuum vessel. https://arxiv.org/abs/2603.11549

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