A new 14 GHz Electron-Cyclotron-Resonance Ion Source (ECRIS) for the heavy ion accelerator facility ATLAS

A 14 GHz Electron-Cyclotron-Resonance Ion Source (ECRIS) has been designed and built at Argonne National Laboratory. The source is a modification of the AECR at Berkeley and incorporates the latest results from ECR developments to produce intense beams of highly charged ions, including an improved magnetic confinement of the plasma electrons with an axial mirror ratio of 3.5. The aluminum plasma chamber and extraction electrode as well as a biased disk on axis at the microwave injection side donates additional electrons to the plasma, making use of the large secondary electron yield from aluminum oxide. The source is capable of ECR plasma heating using two different frequencies simultaneously to increase the electron energy gain for the production of high charge states. The main design goal is to produce several e{mu}A of at least {sup 238}U{sup 35+} in order to accelerate the beam to coulomb-barrier energies without further stripping. First charge state distributions for gaseous elements have been measured and 210 e{mu}A {sup 16}O{sup 7+} has been achieved. A normalized 90% emittance from 0.1 to 0.2 {pi} mm{sm_bullet}mrad for krypton and oxygen beam has been found

A new 14 GHz electron-cyclotron-resonance ion source (ECRIS) for the heavy ion accelerator facility ATLAS: a status report

A new 14 GHz ECRIS has been designed and built over the last 2 years. The source, a modification of the Berkeley AECR, incorporates the latest results from ECR developments to produce intense beams of highly charged ions, i.e., an improved electron confinement with an axial magnetic mirror ratio of 3.5 and a radial magnetic field inside the plasma chamber of 1.0 T. The aluminium plasma chamber and extraction electrode as well as a biased disk on axis at the microwave injection side donate additional electrons to the plasma, making use of the large secondary electron yield from Al oxide. Slots in the plasma chamber allow for radial pumping which increases the AECR performance. The source will also be capable of additional ECR plasma heating using two frequencies simultaneously to increase the electron energy gain for producing high charge states. To be able to deliver usable intensities of the heaviest ion beams, the design will also allow for axial access for metal evaporation ovens and solid material samples using plasma sputtering. Main design goal is to produce several e{mu}A of U{sup 34+} in order to obtain Coulomb- barrier energies from ATLAS without further stripping

Current Carrying Edge Channels and the Role of Contacts in the Quantum Hall Regime

By selectively populating spin resolved edge channels using Schottky gates we experimentally investigate the transition from adiabatic to equilibrated transport in the Quantum Hall regime. The scattering processes within a contact e. g. provide an excellent possibility to equilibrate nonequally populated edge channels. Here we demonstrate that not only with metallic reservoirs but also with increasing temperature one can study the crossover from adiabatic to equilibrated transport. Increasing the current results in a transition from edge channel to bulk transport