Target charging during laser ablation of polyethylene

0490025 - FZÚ 2019 RIV DE eng J - Journal Article
Delle Side, D. - Caricato, A. P. - Krása, Josef - Nassisi, V.
Target charging during laser ablation of polyethylene.
Applied Physics A - Materials Science & Processing. Roč. 124, č. 2 (2018), s. 1-5, č. článku 138. ISSN 0947-8396. E-ISSN 1432-0630
Institutional support: RVO:68378271
Keywords : laser ablation of polyethylene * target charging
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 1.784, year: 2018

The laser-matter interaction generates a time-varying current between the target and the grounded vacuum chamber. This current is composed by three distinct phases, namely, the ignition phase, active phase, and afterglow phase. We investigate the dependence of these current structures on the dimensions of the target, using ultra-high molecular weight polyethylene disks of different thickness. We provide evidence to explain the origin of such negative peaks. We found, indeed, that target initially charges positively under the action of the laser pulse, leading to a first negative target current peak. Then, a net charge unbalance is produced that further attracts free electrons on target surface. This behavior is enhanced if an opportune static electric field is imposed between the target and an opposite electrode.
Permanent Link: http://hdl.handle.net/11104/0284334