Experimental perspectives for systems based on long-range interactions

TL;DR

This paper explores the potential to observe long-range interaction phenomena, especially Quasi-Stationary States, in systems like FEL and CARL, linking experimental results with theoretical models such as HMF.

Contribution

It establishes strong connections between the HMF model and the dynamics of FEL and CARL devices, proposing experimental perspectives to observe QSS features.

Findings

Evidence of phase transition analogs in FEL and CARL systems.

Formal link between dissipative CARL and HMF model.

Calculations based on existing experimental devices.

Abstract

The possibility of observing phenomena peculiar to long-range interactions, and more specifically in the so-called Quasi-Stationary State (QSS) regime is investigated within the framework of two devices, namely the Free-Electron Laser (FEL) and the Collective Atomic Recoil Laser (CARL). The QSS dynamics has been mostly studied using the Hamiltonian Mean-Field (HMF) toy model, demonstrating in particular the presence of first versus second order phase transitions from magnetized to unmagnetized regimes in the case of HMF. Here, we give evidence of the strong connections between the HMF model and the dynamics of the two mentioned devices, and we discuss the perspectives to observe some specific QSS features experimentally. In particular, a dynamical analog of the phase transition is present in the FEL and in the CARL in its conservative regime. Regarding the dissipative CARL, a formal link is established with the HMF model. For both FEL and CARL, calculations are performed with reference to existing experimental devices, namely the FERMI@Elettra FEL under construction at Sincrotrone Trieste (Italy) and the CARL system at LENS in Florence (Italy).