Loading...
Please wait, while we are loading the content...
Similar Documents
E-cloud build-up in grooved chambers.
| Content Provider | CiteSeerX |
|---|---|
| Author | Venturini, M. |
| Abstract | We simulate electron cloud build-up in a grooved vac-uum chamber including the effect of space charge from the electrons. We identify conditions for e-cloud suppression and make contact with previous estimates of an effective secondary electron yield for grooved surfaces. SUMMARY OF WORK Corrugating the interior of a vacuum chamber with small grooves is one of the possible remedies currently investi-gated for suppressing the electron cloud accumulation in storage rings. Analytical and numerical modelling of the interaction of electrons with grooved surfaces have indi-cated the effectiveness of this technique and accelerator-based experiments to confirm these results are planned or already underway. Previous simulations [1, 2, 3] so far have generally aimed at determining an effective secondary elec-tron yield (SEY) by considering a beam of monochromatic electrons (primary particles) impinging on the grooved sur-face and keeping track of the electrons (secondary parti-cles) emerging from the groove regions – a setting typi-cal of laboratory bench measurements where an effective SEY can easily be determined as a function of the energy of the primary electron beam. In the work described here we are interested in a direct characterization of the elec-tron cloud build-up in the vacuum chamber of an operating accelerator in the presence of both the driving beam and space-charge from the electrons. This will be useful for a closer comparison between current e-cloud modelling and accelerator-based measurements. We carried out our work by augmenting the current ver-sion of the code POSINST to include the option to follow the electron dynamics in the presence of grooves. Electron-surface collisions and secondary electron production fol-lowing those collisions are modelled using the modules al-ready built in POSINST [4]. At present we have a provi-sion to simulate rectangular cross-section vacuum cham-bers with triangular grooves located on the top and bottom sides – closely reproducing the configuration a proposed e-cloud experiment at PEP-II. The steepness angle α of the triangular grooves as well their height (see Fig. 1) are input parameters controlled by the user. An option to include rounding of the groove tips has also been implemented. Space charge from the electrons is included in the model. |
| File Format | |
| Access Restriction | Open |
| Subject Keyword | E-cloud Build-up Grooved Chamber Triangular Groove Vacuum Chamber Space Charge Grooved Surface Driving Beam Monochromatic Electron Storage Ring Numerical Modelling Secondary Electron Production Fol-lowing Previous Estimate Effective Secondary Electron Yield Primary Particle Code Posinst E-cloud Suppression E-cloud Experiment Groove Tip Summary Work Primary Electron Beam Secondary Parti-cles Current Ver-sion Previous Simulation Effective Secondary Elec-tron Yield Direct Characterization Laboratory Bench Measurement Current E-cloud Modelling Electron Cloud Build-up Electron Cloud Accumulation Operating Accelerator Possible Remedy Accelerator-based Measurement Effective Sey Accelerator-based Experiment Rectangular Cross-section Vacuum Cham-bers Electron Dynamic Grooved Vac-uum Chamber Electron-surface Collision Small Groove Steepness Angle Elec-tron Cloud Build-up Bottom Side Input Parameter |
| Content Type | Text |
