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ISSN Online: 2379-1748

ISBN Flash Drive: 978-1-56700-469-4

ISBN Online: 978-1-56700-470-0

Second Thermal and Fluids Engineering Conference
April, 2-5, 2017, Las Vegas, NV, USA

HEAT TRANSFER ANALYSIS IN A HIGHER ORDER MODE WAVEGUIDE FOR THE ELECTRON − ION COLLIDER AT BNL

Get access (open in a dialog) pages 211-220
DOI: 10.1615/TFEC2017.cfn.017964

Аннотация

A key component of the proposed Electron − Ion Collider (EIC) at Brookhaven National Laboratory (BNL) are the Superconducting Radio Frequency (SRF) cavities. SRF cavities are responsible for generating electric fields that oscillate at radio frequencies, which are used in accelerating charged particle beams. Charged particle beams have their own Electric Fields which upon interaction with the field in the RF cavity, generate Higher Order Modes (HOM) of EM oscillations which can be harmful to the charged particle beam if left unchecked. This HOM wave energy can be considerable and it is therefore not desirable to extract this energy at cryogenic temperatures due to the considerable increase in size of the cryogenic cooling system. HOM waveguides are used to divert this energy from the cold cavity, and is then damped/extracted at room temperature. The SRF cavities operate at 2K and the cryogenic system is typically engineered to provide heat intercept capability at 5K, 35K and additional temperature levels if required. From the thermal standpoint, HOM waveguides provide the unwanted link between room temperature and the cold end thus adding a static thermal load. The other contribution to the thermal load comes from the joule heating of the HOM waveguide due to the passing RF wave. The main aim of this study is to try and reduce the additional load at the 2K cold end and to optimize heat stations' location along the waveguide. We use ANSYS mechanical to model the problem, with RF load being modelled with a false-convection boundary condition and present the results of our analysis in the following sections. The analysis helps us decide if this is a feasible design for a HOM waveguide from both the RF and thermal standpoints.