ESS Docs Document 152-v1

DocDB Home ]  [ Search ] [ Last 20 Days ] [ List Authors ] [ List Topics ] [ List Events ]

Optimising high-power input couplers

Document #:
Document type:
Tech Note
Submitted by:
Stephen Molloy
Updated by:
Stephen Molloy
Document Created:
22 Nov 2011, 00:20
Contents Revised:
22 Nov 2011, 00:20
Metadata Revised:
22 Nov 2011, 00:20
Viewable by:
  • Public document
Modifiable by:

Quick Links:
Latest Version

Given a free choice of the transformer ratio of the input coupler, and the frequency detuning of the cavity, the power reflected from a beam-loaded RF cavity may be set to zero for a particular accelerating field and beam current. Given that it is unfeasible to choose a different coupling for every cavity in a large linac, the value of the coupling may be chosen so as to minimise the total reflected power from each family of cavities.

This note outlines such a calculation, and confirms that the coupling strengths already chosen for each of the three superconducting cavity families intended to be used in ESS are very close to optimal.

Depending on the commissioning and upgrade scenarios, it may be advantageous to design the couplers for a beam current lower than the nominal machine design, since this may help to increase the range of currents that may be accelerated in this linac.

Files in Document:
coupler scrf rf cavity
DocDB Home ]  [ Search ] [ Last 20 Days ] [ List Authors ] [ List Topics ] [ List Events ]

DocDB Version 8.8.9, contact Document Database Administrators