[518] Design, manufacture, factory testing and delivery of 1.5 MW, 704 MHz pulsed power klystrons

The ESS linac includes two specific sections, the ‘Medium Beta’ and ‘High Beta’, each containing strings of accelerating structures designed for high power pulsed operation at 704.42 MHz. At present, 36 1.5 MW pulsed power klystrons are installed in the Medium Beta section, and 20 klystrons of the same type are installed in the High Beta section, each feeding a superconducting cavity. In its final stage of expansion, the High Beta section is planned to contain 84 superconducting cavities, each foreseen to be supplied by a single klystron. It is anticipated that each klystron will operate for approximately 6000 hours per year from 2027 on. In this tender, ESS plans to procure up to 24 klystrons as spares for the already commissioned parts of the linac, for superconducting cavity test stands and for a possibly near-term extension of the High Beta part of the linac. The klystrons are a crucial component for the ESS project and to reduce risk and to ensure sufficient long-term manufacturing capacity, provided there are no other overriding grounds, ESS wishes to have the klystrons manufactured by two different suppliers at different sites. ESS also wishes to reuse the magnet, frame and oil tank of the klystron assemblies supplied under this contract after the klystrons have reached their end of life. It should therefore be possible, for ESS with a reasonable level of effort, to operate new klystrons from the same manufacturer, in the magnets and frames supplied under this tender. As such the magnets shall be designed to be robust, with good field performance, such that only minor corrections to the focussing currents are necessary to operate with different klystrons.

External link to procurement, here