  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.
