Speaker
Description
The AWAKE experiment is now in its Run 2b phase. The main aim is to study the effect of a density step placed along the plasma to control the evolution of wakefields induced by a long proton bunch. Numerical simulation results predicted that, after saturation of the self-modulation process, wakefields maintain a larger amplitude with the step than in a uniform density plasma. A new rubidium vapor source has been designed, fabricated, and installed in 2023. It allows to impose a temperature, and thus a vapor density, and upon ionization, a plasma density step, up to 10% in relative height every 50cm over the first 4.5m of the source. Furthermore, in 2024 a number of movable screens were installed to allow to vary the plasma length by blocking the ionizing laser pulse at various positions, 1m apart along the source. The source is now under test with proton beam. In this contribution we will present the characteristics and the challenges of the new source, as well as the first applications to the propagation of the proton bunch in plasma.
