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ISSN Online: 2688-7231

ISBN Online: 978-1-56700-478-6

Proceedings of the 24th National and 2nd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2017)
December, 27-30, 2017, BITS Pilani, Hyderabad, India

THERMO-MECHANICAL ANALYSIS OF RF LINAC CAVITY

Get access (open in a dialog) DOI: 10.1615/IHMTC-2017.1140
pages 805-811

Abstract

A RF LINAC Cavity consisting of 17 cells made of Oxygen-Free High Conductivity (OFHC) Copper is studied. During its Operation, RF pulsed heating takes place that is local joules heating that occur on the metal surface due to eddy currents created from pulsed RF power. The change in shape of cavity due to thermal heating i.e. the change in cavity dimensions affect the tuning of cavity and limits the maximum achievable accelerating gradient as well as performance of linear accelerating structure. Water cooling is provided to the cavity by brazing copper tube spirally over the cavity surface. Conjugate Heat Transfer coupled with Structural analysis for the cavity has been carried out using CFD code. The purpose of this paper is to estimate the radial and axial temperature gradients in the LINAC cavity and to parametrically see the effect of varying heat load and flow rate of water on the frequency shift in RF LINAC Cavity. The simulation result shows that, temperature is significantly higher in the cavity cell close to outlet of cooling channel. The temperature of the cavity increased linearly with increasing heat load and decreased with increase in water flow rates. Maximum Deformation of the cavity occurred in the outer dome of central cavity cells from the flange. The Mechanical stresses induced were higher in the central cavity cells but they remained below yield stress of OFHC Copper throughout the study. Based on the cavity deformation, calculated frequency shift increased with applied increasing heat load and decreased with increase in flow rate of water in the helical cooling coil.