Accelerator Modelling: Electron-Cloud effect Visualization

Table of Contents

Introduction

This project, a collaboration with Andreas Adelmann from PSI, aims at studying the electron cloud instabilities that can disrupt the main accelerator beam[1]. The simulation results, which consist of particles' (protons, electrons) position and phase (velocity), are large and complex datasets that are difficult to manipulate and understand[2].

We continued our work (See SC04 for a reference to last year's work) with Andreas Adelmann to visualize the charge neutralization along the beam pipe.

3D Visualization Gallery

Figure 1. AVS/Express application showing the beam pipe colored by the charge along the beam pipe axis and the proton beam with it's convex hull.
We used AVS/Express and the H5Part API [3]i to read particle data stored in HDF5 format and to explore possible visualization techniques to show the neutralization of the beam due to the electron presence in the beam pipe. Figure 1. shows the beam pipe and the proton beam with it's convex hull. The pipe was colored by the charge along the pipe axis. Blue is negative and red is positive charge. Figure 2. shows the electron cloud renderend as particles and a detail of the neutralization of the proton beam. Figure 3. shows the pipe colored by the energy of particles that are a dR away from the wall. Figure 4. shows the time evolution of the electron density along the pipe as the simulation progresses.

Figure 2. Left: Proton and electron beam rendered as particles, Right: detail of the neutralization of the proton beam along the beam pipe.



Figure 3. Energy of particles that are a dR of the beam pipe. dR is an adjustable parameter of the visualization application.



Figure 4. Beam pipe colored by the density of electrons along the pipe axis and corresponding graph of these values. Click here to see a time evolution MPEG

References

[1] 3D simulations of space charge effects in practicle beams , Andreas Adelmann, Diss., Mathematische Wissenschaften ETH Zürich, Nr. 14545, 2002
[2] From Visualization to data mining with large data sets, Andreas Adelmann (PSI, Villigen), Robert Douglas Ryne, John M. Shalf, Cristina Siegerist (LBNL, Berkeley, California), Particle Accelerator Conference, Knoxville, Tennessee, 2005.
[3] H5Part: A Portable High Performance Parallel Data Interface for Particle Simulations, Andreas Adelmann (PSI, Villigen), Robert Douglas Ryne, John M. Shalf, Cristina Siegerist (LBNL, Berkeley, California), Particle Accelerator Conference, Knoxville, Tennessee, 2005.