Master's Thesis

Cool-down and Warm-up of the Cryogenic Distribution Line at ESS

Riccard Andersson


The European Spallation Source, ESS, is a joint collaboration of 17 European countries, where the world’s most powerful neutron source will be built for future research within a vast variety of fields. In order to deliver the highly energetic neutrons, protons are accelerated to energies in the GeV range and then collided with a spallation target. This acceleration process requires superconducting cavities cooled down to slightly over 2 K, and this cooling is done through the cryogenic system using helium.

In this project, the cryogenic system at ESS has been modeled in Dymola. Simulations have been made of the cool-down and warm-up of the superconducting part of the accelerator. This was done in separate simulations for the cryogenic distribution line and for an individual cryomodule. Additionally, a model was created for the helium discharge system, in order to size the vent line leading rapidly expanded
helium from the cold masses back to the cryoplant. The mathematical tools and structure of the modeling are described in a separate chapter.

Master's Thesis ISRN LUTFD2/TFRT--5939--SE, Department of Automatic Control, Lund University, Sweden, 2014.