Characterisation of a localised broad-band impedance phenomenon on the SRS

Author

Hill, S.F.

Author_Institution

SERC Daresbury Lab., Warrington, UK

Volume

5

fYear

1995

fDate

1-5 May 1995

Firstpage

3122

Abstract

A major perturbation to the SRS vacuum envelope was required to install a second superconducting wiggler in 1992. As part of this, all of the new wiggler straight (straight 16) vacuum vessels were re-designed to give a good match to the small elliptical chamber of the wiggler, including the sector vacuum isolation valve. Because of engineering problems this valve was not fitted and a standard circular aperture valve of much larger diameter had to be installed. This caused a localised impedance, which manifested itself by gross overheating due to the energy dissipated in it from the beam. A study of the effect of this valve has been conducted and is summarised. All data from the period of installation in the ring is collated, including beam heating and instability data. On removal from the ring a bench measurement of the effective broad-band impedance has been made, using time-domain measurement techniques

Keywords

accelerator magnets; electron accelerators; particle beam diagnostics; particle beam stability; storage rings; superconducting magnets; vacuum apparatus; valves; wigglers; SRS; beam heating; beam instability; bench measurement; circular aperture valve; gross overheating; localised broad-band impedance; sector vacuum isolation valve; small elliptical chamber; superconducting wiggler; time-domain measurement; vacuum envelope perturbation; wiggler straight vacuum vessels; Apertures; Cooling; Heating; Impedance; Lattices; Superconducting magnets; Temperature; Undulators; Vacuum systems; Valves;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 1995., Proceedings of the 1995

Conference_Location

Dallas, TX

Print_ISBN

0-7803-2934-1

Type

conf

DOI

10.1109/PAC.1995.505804

Filename

505804