IPAC2012 - List of Authors (Ainsworth, R.)

Paper	Title	Page
WEEPPB008	HOM Coupler Optimisation for the Superconducting RF Cavities in ESS	2182
	R. Ainsworth Royal Holloway, University of London, Surrey, United Kingdom R. Calaga CERN, Geneva, Switzerland S. Molloy ESS, Lund, Sweden
	The European Spallation Source (ESS) will be the world’s most powerful next generation neutron source. It consists of a linear accelerator, target, and instruments for neutron experiments. The linac is designed to accelerate protons to a final energy of 2.5 GeV , with an average design beam power of 5 MW, for collision with a target used to produce a high neutron flux. A section of the linac will contain Superconducting RF (SCRF) cavities designed to resonate at 704 MHz. Dangerous beam induced modes in these cavities may make the beam unstable and increase the cryogenic load and so couplers are usually installed to provide damping. Previous studies have shown potential designs are susceptible to multipacting, a resonant process which can absorb RF power and lead to heating effects. This paper will show how a coupler suffering from multipacting has been redesigned to limit this effect. Optimisation of the RF damping is also discussed.

Paper

Title

Page

HOM Coupler Optimisation for the Superconducting RF Cavities in ESS

2182

R. Ainsworth
Royal Holloway, University of London, Surrey, United Kingdom
R. Calaga
CERN, Geneva, Switzerland
S. Molloy
ESS, Lund, Sweden

The European Spallation Source (ESS) will be the world’s most powerful next generation neutron source. It consists of a linear accelerator, target, and instruments for neutron experiments. The linac is designed to accelerate protons to a final energy of 2.5 GeV , with an average design beam power of 5 MW, for collision with a target used to produce a high neutron flux. A section of the linac will contain Superconducting RF (SCRF) cavities designed to resonate at 704 MHz. Dangerous beam induced modes in these cavities may make the beam unstable and increase the cryogenic load and so couplers are usually installed to provide damping. Previous studies have shown potential designs are susceptible to multipacting, a resonant process which can absorb RF power and lead to heating effects. This paper will show how a coupler suffering from multipacting has been redesigned to limit this effect. Optimisation of the RF damping is also discussed.