Laser experiment for the study of accretion dynamics of Young Stellar Objects: design and scaling

TL;DR

This paper presents a novel laser-based experimental setup to simulate and study the accretion dynamics of young stellar objects, linking laboratory plasma behavior to astrophysical phenomena in T Tauri stars.

Contribution

It introduces a new experimental configuration that mimics stellar accretion processes and analyzes plasma expansion, bridging laboratory results with astrophysical accretion models.

Findings

Experimental plasma stream characteristics match 1D adiabatic expansion model.

The setup replicates high plasma β conditions of certain T Tauri star accretion scenarios.

Dimensionless parameters indicate the experiment's relevance to ideal MHD regimes.

Abstract

A new experimental set-up designed to investigate the accretion dynamics in newly born stars is presented. It takes advantage of a magnetically collimated stream produced by coupling a laser-generated expanding plasma to a $2\times 10^{5}~{G}\ (20~{T})$ externally applied magnetic field. The stream is used as the accretion column and is launched onto an obstacle target that mimics the stellar surface. This setup has been used to investigate in details the accretion dynamics, as reported in [G. Revet et al., Science Advances 3, e1700982 (2017), arXiv:1708.02528}. Here, the characteristics of the stream are detailed and a link between the experimental plasma expansion and a 1D adiabatic expansion model is presented. Dimensionless numbers are also calculated in order to characterize the experimental flow and its closeness to the ideal MHD regime. We build a bridge between our experimental plasma dynamics and the one taking place in the Classical T Tauri Stars (CTTSs), and we find that our set-up is representative of a high plasma $\beta$ CTTS accretion case.