Beam dynamics challenges in linear colliders based on laser-plasma accelerators

Abstract

In this paper we discuss design considerations and beam dynamics challenges associated with laser-driven plasma-based accelerators as applied to multi-TeV-scale linear colliders. Plasma accelerators provide ultra-high gradients and ultra-short bunches, offering the potential for compact linacs and reduced power requirements. We show that stable, efficient acceleration with beam quality preservation is possible in the nonlinear bubble regime of laser-plasma accelerators using beam shaping. Ion motion, naturally occuring for dense beams (i.e., low emittance and high energy) severely damps transverse beam instabilities. Coulomb scattering by the background ions is considered and it is shown that the strong focusing in the plasma strongly suppresses scattering-induced emittance growth. Betatron radiation emission from the transverse motion of the beam in the plasma will result in beam power loss and energy spread growth; however for sub-100 nm emittances, the beam power loss and energy spread growth will be sub-percent for multi-TeV-class plasma linacs.

On possibility of low-emittance high-energy muon source based on plasma wakefield acceleration

“…Quasi-linear regime takes place in the case of low intensity drivers, while for the high intensities the plasma channel sustains so called bubble regime, where (almost) all the electrons are expelled by either the drive 𝑒 − beam of by the laser ponderomotive force, forming an ion cavity co-propagating behind the laser. The structure of wakefield forces inside the ion cavity in the bubble regime is (see, e.g., [8]…”

“…To be noted, some emittance growth may occur by elastic scattering of the beam muon against the background ions in the plasma, but as shown elsewheresee, e.g., ref. [8] -the strong focusing in the plasma bubble suppresses the growth. The effect is almost independent on the plasma density and is very small even for electrons, while for muons it is negligible due to additional suppression factor (𝑚 𝑒 /𝑚𝜇).…”

Fabrication of THz corrugated wakefield structure and its high power test

“…In order to overcome the primary limit of conventional linear accelerator, the Advanced Accelerator Concepts (AAC) have been proposed and demonstrated for realizing future energy-frontier colliders 1 – 6 and compact multi-beamlines X-ray free electron lasers 7 – 9 . Structure wakefield acceleration (SWFA) is one of the AAC that utilizes particle beams (= I) and high impedance structures (= R) to generate intense electromagnetic fields (= V) called wakefield 10 , 11 .…”

Linear colliders based on laser-plasma accelerators

“…Table 3 shows an example of single-stage LPA parameters operating in the bubble regime. This single-stage LPA example is based on PIC modeling of the nonlinear laser-plasma interaction [56]. The laser energy depletion at the end of the stage is 20%.…”