Study of field imperfections for antimatter experiments at CERN
In August 2019, AVA Fellow Volodymyr Rodin spent one week on secondment in CERN. He was based at Meyrin site and, together with researches from AEgIS, spent his time investigating one of the possible issues for the future antimatter measurements.
In his previous works, it was shown that comprehensive explorative approach is possible by modification of existing tools. A full 3D model of the electrostatic beamline from ELENA to the ALPHA experiment was implemented in a well-known tool G4beamline. It is obvious that at such a low energy scale(100 keV), even small electrostatic or magnetic field imperfections will have a significant impact on the orbit and quality of the beam. The stray fields belong to these problems.
Thus, an influence of AEgIS experimental setup on the performance of the closest transfer line towards ALPHA was checked. The main source of an additional field is solenoidal magnets. By combining the efforts of our fellow and AD engineers precise description of these has to be implemented.
Transfer lines to AEgIS and ALPHA with stray field(blue) created by solenoids.
The first step was already made and the existing model was extended to include a branch of the AEgIS transfer line. United simulation of magnets was performed in CST and OPERA. The next steps will include field mitigation studies using obtained AD experimental hall drawings.
Special thanks for the fruitful discussions belongs to AEgIS technician Stefan Haider and people providing information about the planning of Antimatter Factory, Francois Butin and Olivier Choisnet.