Speaker
Description
In order to address some still open questions in physics, a new accelerator, MESA (Mainz Energy-Recovery Superconducting Accelerator), is currently under construction in Mainz, Germany. MESA will be the world's first accelerator to use superconducting energy-recovery technology. This will allow for an electron beam with high intensity, up to 10 mA, and low energy, up to 105 MeV, enabling a next phase of high-precision experiments.
MAGIX (MAinz Gas Injection target eXperiment) will be one of the key experiments at MESA and will use the Energy-Recovery Linac (ERL) mode of operation. With this cutting-edge technology, MAGIX will offer a versatile physics program ranging from studies of baryonic matter to searches for dark-sector particles.
To fulfill the experimental requirements of MAGIX, a state-of-the-art target is needed. For the ERL to operate, the target must be thin enough to minimize the beam energy loss. On the other hand, a high target density is required to achieve the necessary luminosity for the experiments. Additionally, the target must be windowless to avoid an irreducible background and beam energy loss in the window material. It should also be operable with different gases, depending on the experimental requirements.
To meet these challenging requirements, MAGIX will use a cryogenic windowless jet target that can be operated with various gases, including hydrogen, helium, and almost all heavier gases. When operated with hydrogen, the MAGIX jet target can deliver a high-density jet of up to $10^{18}$ atoms/cm$^2$ at the interaction point. Achieving such a high target density requires a large gas flow rate at cryogenic temperatures. To reach the desired temperature, the gas is first precooled with liquid nitrogen and then further cooled using a powerful dual-stage cold head. The cooled gas is then pressed through a specially designed convergent-divergent nozzle. This produces a supersonic jet with a very small divergence and a well-defined structure.
The nozzle geometry defines how the jet target expands into vacuum. Therefore, numerical simulations of the jet formation and propagation are performed to understand and optimize target performance. In this contribution, the setup and optimization of the MAGIX jet target will be presented, with a focus on numerical simulations for different gases. In addition, frozen filament jets can be generated in Münster. Plans and activities toward adapting the MAGIX jet target for the generation of a frozen filament jet structure will be described and presented.