Abstract
Seeded Self-modulation (SSM) has been demonstrated to transform a long proton bunch into many equidistant micro-bunches (e.g., the AWAKE case), which then resonantly excite strong wakefields. However, the wakefields in a uniform plasma suffer from a quick amplitude drop after reaching the peak. This is caused by a significant decrease of the wake phase velocity during self-modulation. A large number of protons slip out of focusing and decelerating regions and get lost, and thus cannot contribute to the wakefield growth. Previously suggested solutions incorporate a sharp or a linear plasma longitudinal density increase which can compensate the backward phase shift and therefore enhance the wakefields. In this paper, we propose a new plasma density profile, which can further boost the wakefield amplitude by 30%. More importantly, almost 24% of protons initially located along one plasma period survive in a micro-bunch after modulation. The underlying physics is discussed.
Original language | English |
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Article number | 042009 |
Number of pages | 5 |
Journal | Journal of Physics: Conference Series |
Volume | 1067 |
Issue number | 4 |
DOIs | |
Publication status | Published - 5 Oct 2018 |
Event | 9th International Particle Accelerator Conference, IPAC 2018 - Vancouver, Canada Duration: 29 Apr 2018 → 4 May 2018 |