Volume 109, Number 2, January 2015
|Number of page(s)||6|
|Section||Physics of Gases, Plasmas and Electric Discharges|
|Published online||04 February 2015|
On the role of the ablated mass on the propagation of a laser-generated plasma in an ambient gas
1 Dipartimento di Fisica e di Scienze della Terra, Università degli Studi di Messina Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy
2 CNR-IPCF Istituto per i Processi Chimico-Fisici - Viale F. Stagno d'Alcontres 37, 98158, Messina, Italy
3 Dipartimento di Energia, Center for NanoEngineered Materials and Surfaces-NEMAS, Politecnico di Milano Via Ponzio 34-3, 20133, Milano, Italy
Received: 20 August 2014
Accepted: 15 January 2015
We investigate the influence of the ablated mass on the dynamics of a laser-generated plasma expanding in an ambient gas. A laser-generated silver plasma expanding in argon was analysed by fast photo imaging. While keeping all relevant experimental parameters fixed, we changed the ablated mass per pulse, by changing the laser spot area at the target surface. We show that at fixed laser fluence, plasma dynamics undergoes dramatic changes as a function of the ablated mass per pulse. Plasma expansion dynamics is studied using drag, v2-drag, mixed propagation and Predtechensky-Mayorov models. Results show that, at a given laser fluence, when a shock wave forms, plasma dynamics is unequivocally determined by the ratio between the ablated mass per pulse and the gas density. Such a dynamics critically affects the kinetic energy at landing and the nanostructure resulting upon mutual assembling on the substrate of the deposited nanoparticles. Thus both the ablated mass per pulse and the laser fluence are to be known to control the nanostructure formation.
PACS: 52.38.Mf – Laser ablation / 82.33.Xj – Plasma reactions (including flowing afterglow and electric discharges) / 52.35.Tc – Shock waves and discontinuities
© EPLA, 2015
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.