Warning: We observe an increase of emails from fake travel portals like . "travelhosting.co.uk". We never send links to such portals so be vigilant!

Dec 8 – 9, 2022
Marriott
Europe/Berlin timezone

Design and construction of a levitated dipole trap for pair plasma studies

Dec 8, 2022, 4:15 PM
25m
Marriott

Marriott

Talk (20 min + 5 min discussion) Positrons Positrons

Speaker

Alexander Card (Max-Planck-Institut für Plasmaphysik)

Description

Magnetic dipole traps have demonstrated good confinement properties for both non-neutral and quasi-neutral plasmas, making them highly suitable for the creation and study of low-temperature, long-lived electron-positron pair plasmas. To generate such a plasma, the APEX (A Positron-Electron eXperiment) Collaboration is planning to inject positrons (supplied by the reactor-based beam NEPOMUC, then collected into pulses in a buffer-gas trap) into a dipole magnetic field, which is previously loaded with a comparable population of electrons. Our dipole trap is a 15-cm-diameter high-temperature superconducting (HTS) closed coil, which is cryogenically cooled (20 K) and inductively charged (56 kAt, B$_{axis}$= 0.5 T). Levitation prevents particle losses through the intersection of magnetic field lines with material surfaces (e.g. mechanical supports). By directly exposing the coil to room temperature thermal radiation, we observed a worst-case warming rate that limits available levitation time to 96 min. Simulations have shown that a technique for injecting positrons across magnetic field lines (previously demonstrated in a prototype supported dipole trap) is expected to be transferrable to the higher fields and symmetric geometry of the levitated dipole trap. The construction of the levitated dipole trap itself is nearing completion, with commissioning and electron experiments anticipated to take place by the end of 2022.

Primary author

Alexander Card (Max-Planck-Institut für Plasmaphysik)

Co-authors

APEX Collaboration (Max-Planck-Institut f für Plasmaphysik) Adam Deller (Max-Planck-Institut f für Plasmaphysik) E. V. Stenson (Max-Planck-Institut f für Plasmaphysik) Jens von der Linden (Max-Planck-Institut f für Plasmaphysik) Juliana Horn-Stanja (Max-Planck-Institut f für Plasmaphysik) Matthew Stoneking (Max Planck Institute for Plasma Physics) Thomas Sunn Pedersen (Max-Planck-Institut für Plasmaphysik)

Presentation materials

There are no materials yet.