Laser ablation of CsI analyzed by delayed extraction

• Published in: Applied surface science Vol. 217; no. 1; pp. 202 - 209
• Main Authors: Fernández-Lima, F, Collado, V.M, Ponciano, C.R, Farenzena, L.S, Pedrero, E, da Silveira, E.F
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.07.2003; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Delayed extraction; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Impact phenomena (including electron spectra and sputtering); Laser ablation; Laser-beam impact phenomena; Laser-plasma interactions; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma diagnostic; Plasma temperature; TOF; 52.50.Jm; 52.50.-m; Plasma diagnostic; TOF; 81.15.Fg; 82.80.Ms; Laser ablation; Delayed extraction; Plasma temperature; Ultraviolet laser; Laser-produced plasma; Time-of-flight method; Mass spectroscopy; Cesium iodides; Pulsed lasers; Plasma diagnostics; Photoionization; Secondary ion emission; One dimensional model; Extraction; Laser ablation technique; Diffusion; Drift velocity; 52.50.-m Laser ablation
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/S0169-4332(03)00547-6

Secondary ion emission from polycrystalline CsI irradiated by pulsed-UV laser (337 nm) is analyzed by time-of-flight (TOF) mass spectrometry. Measurements were performed for different laser intensities and for several delayed extraction times (0–200 ns). The TOF peak shape is characterized by a Gaussian-like structure (fast component), followed by a tail (slow component) that is more pronounced when the extraction field is delayed. A thermal-sputtering uni-dimensional model is employed to describe the solid surface and plasma temperatures as a function of time. Heat diffusion, vapor photo-ionization, radiative emission and plume expansion are considered. Within the approximations used, the model predicts reasonable drift velocities of the plume (≈1.4 km s −1) but very high plasma temperatures (≈10 5 K). The width of the TOF peak fast component allows determination of the plume temperature during its expansion.