Description
The main goal of the APEX (A Positron Electron eXperiment) Collaboration is the creation and study of a quasi-neutral, low-temperature, matter-antimatter pair plasmas, using positrons and electrons. For this aim, we built an array of non-neutral plasma (NNP) traps for the generation of bright positron pulses. These pulses will be mixed with electrons in our neutral-plasma traps: a levitated dipole trap (LD), which is complete and being used for studies of pure-electron plasmas, and an optimized tabletop stellarator (EPOS), which is scheduled to be assembled this year. For the diagnosis of the positron containing plasmas, a dedicated system of up to 48 gamma-ray detectors will enable fast, spatially resolved annihilation measurements.
In 2026, the NNP and the LD traps will finally be integrated into the positron beamline at the Research Neutron Source Heinz Maier-Leibnitz (FRM2). The Neutron-induced POsitron source MUniCh (NEPOMUC) at FRM2 is the brightest cold positron source worldwide, delivering a moderated beam of $5\times10^{7}$ positrons per second. With this positron source and our NNP traps we expect to create well-defined pulses of $\sim 10^{8}$ positrons every 30s.
We will present the details of the new positron laboratory, its mode of operation, and expected capabilities. In addition to our NNP traps and the LD, it is designed to allow for the introduction of additional future components, e.g., a high-field trap as a second accumulation stage or other experiments. APEX’s pulsed positron laboratory is planned as a versatile platform for positron-based experiments. With its diagnostic capabilities and high repetition rate of well-defined positron pulses it presents a novel opportunity for the development of plasma diagnostics using positrons - in addition to the study of fundamental plasma phenomena in pair plasmas.