CYCLOTRONS 2010 - List of Keywords (septum)

Paper	Title	Other Keywords	Page
WEM2CCO03	Disturbance Effects Caused by RF Power Leaking Out From Cavities in the PSI Ringcyclotron	plasma, vacuum, cyclotron, proton	341
	J.M. Humbel PSI-LRF, Villigen, PSI, Switzerland H. Zhang PSI, Villigen, Switzerland
	While commissioning the PSI high intensity proton beam facility after the shutdown 2010 direct and indirect phenomena of interaction between the electrostatic septa of the injection and extraction region and the RF power, leaking out from the cavities occurred in the Ringcyclotron. As an indirect influence RF fields outside the cavities generate plasma clouds at the edge of magnet poles. Accelerated plasma ions sputtered metallic atoms form the vacuum chamber wall, which then covered the insulator surface with an electrically conductive layer. The septum therefore had to be replaced. Directly RF power, dissipated from the third harmonic cavity was redirected by a beam stopper in such a way, that a linear correlation between the RF pick up signal monitored at the extraction septum EEC and the leak current across the septum insulator could be observed. As an instant mending action the beam stopper, which is not permanently used, has been removed. The leaking out of RF power from a cavity is known to depend on vertical asymmetry. With asymmetrical settings of the hydraulic tuning system we will try to minimize this disturbing effect.
	Slides WEM2CCO03 [3.166 MB]

THA1CIO02	First Commissioning Results from the Non-Scaling FFAG Accelerator, EMMA	controls, acceleration, injection, lattice	384
	S.L. Smith STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	The first results from commissioning EMMA - the Electron Model of Many Applications- are summarised in this paper. EMMA is a 10 to 20 MeV electron ring designed to test our understanding of beam dynamics in a relativistic linear non-scaling fixed field alternating gradient accelerator (FFAG). EMMA will be the world's first non-scaling FFAG and the paper will outline the characteristics of the beam injected in to the accelerator as well as summarising the results of the 4 sector 'gantry-type' commissioning which took place at Daresbury Laboratory. The paper will report on recent progress made with the full EMMA ring commissioning, giving details of tune and orbit measurements as well as their correction to the desired lattice.
	Slides THA1CIO02 [5.404 MB]

Paper

Title

Other Keywords

Page

WEM2CCO03

Disturbance Effects Caused by RF Power Leaking Out From Cavities in the PSI Ringcyclotron

plasma, vacuum, cyclotron, proton

341

J.M. Humbel
PSI-LRF, Villigen, PSI, Switzerland
H. Zhang
PSI, Villigen, Switzerland

While commissioning the PSI high intensity proton beam facility after the shutdown 2010 direct and indirect phenomena of interaction between the electrostatic septa of the injection and extraction region and the RF power, leaking out from the cavities occurred in the Ringcyclotron. As an indirect influence RF fields outside the cavities generate plasma clouds at the edge of magnet poles. Accelerated plasma ions sputtered metallic atoms form the vacuum chamber wall, which then covered the insulator surface with an electrically conductive layer. The septum therefore had to be replaced. Directly RF power, dissipated from the third harmonic cavity was redirected by a beam stopper in such a way, that a linear correlation between the RF pick up signal monitored at the extraction septum EEC and the leak current across the septum insulator could be observed. As an instant mending action the beam stopper, which is not permanently used, has been removed. The leaking out of RF power from a cavity is known to depend on vertical asymmetry. With asymmetrical settings of the hydraulic tuning system we will try to minimize this disturbing effect.

Slides WEM2CCO03 [3.166 MB]

THA1CIO02

First Commissioning Results from the Non-Scaling FFAG Accelerator, EMMA

controls, acceleration, injection, lattice

384

S.L. Smith
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

The first results from commissioning EMMA - the Electron Model of Many Applications- are summarised in this paper. EMMA is a 10 to 20 MeV electron ring designed to test our understanding of beam dynamics in a relativistic linear non-scaling fixed field alternating gradient accelerator (FFAG). EMMA will be the world's first non-scaling FFAG and the paper will outline the characteristics of the beam injected in to the accelerator as well as summarising the results of the 4 sector 'gantry-type' commissioning which took place at Daresbury Laboratory. The paper will report on recent progress made with the full EMMA ring commissioning, giving details of tune and orbit measurements as well as their correction to the desired lattice.

Slides THA1CIO02 [5.404 MB]