Keywords
Laser wakefield acceleration
High-energy proton beam
Peak energy
Plasma channel
Submitted : 2026-03-23
Accepted : 2026-04-07
Published : 2026-04-22
Abstract
In the fields of high-energy physics and particle acceleration, the peak energy of a proton beam is a core parameter for characterizing its energy properties. This paper presents a detailed discussion on the evolution of proton peak energy and its dependence on plasma density, combining theoretical research and simulations. The study integrates theoretical and simulation analyses to reveal that the peak energy of protons undergoes three distinct evolutionary stages: First, within a characteristic critical length, the variation in peak energy is independent of the channel density. Second, beyond this threshold length, the proton peak energy exhibits a rising trend over time, demonstrating a nearly linear increase with channel densities. Third, the proton peak energy does not increase indefinitely; it saturates before the protons reach the laser pulse front. Moreover, higher densities lead to earlier saturation of the peak energy. These findings provide an important foundation for future theoretical research on proton acceleration and the design of related experiments.
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