Mirrorlike pulsed laser deposited tungsten thin film

Abstract

Mirrorlike tungsten thin films on stainless steel substrate deposited via pulsed laser deposition technique in vacuum (10(-5) Torr) is reported, which may find direct application as first mirror in fusion devices. The crystal structure of tungsten film is analyzed using x-ray diffraction pattern, surface morphology of the tungsten films is studied with scanning electron microscope and atomic force microscope. The film composition is identified using energy dispersive x-ray. The specular and diffuse reflectivities with respect to stainless steel substrate of the tungsten films are recorded with FTIR spectra. The thickness and the optical quality of pulsed laser deposition deposited films are tested via interferometric technique. The reflectivity is approaching about that of the bulk for the tungsten film of thickness ∼782 nm.

Experimental Simulation of the Behaviour of Diagnostic First Mirrors Fabricated of Different Metals for ITER Conditions

“…Deuterium retention in these conditions is much more efficient than in experiments where hydrogen saturation was studied by exposing the AMA mirror to the gas phase or electrolytic solution. From the measured dependence of the absorbed deuterium mass on the ion fluence (up to 1.5·10 25 ion/m 2 ) it was possible to estimate the efficiency of deuterium absorption to be ~10% for an ion energy of ~60 eV. This is about ten times higher than in the electrolytic hydrogenation experiments [38].…”

“…The Basel group operates with Rh films (and to some extent also Mo films) produced by magnetron sputtering and has a typical thickness ~2 μm (e.g., [23]). The two other groups study the behavior of films obtained by a pulsed laser deposition technique in vacuum [24,25]. All main publications connected with investigation of film mirrors were recently enumerated in a short review [26].…”

“…11) at the total ion fluence of 2.5x10 25 ions/m 2 with an average ion current density of 15 A/m 2 (the total time of exposure to the deuterium plasma exceeded 60 hours). By that time both Be samples still had a mirror-like surface and retained their high ability to transmit an image of a subject (the laser beam spot) practically with similar quality as an aluminum etalon did, refs [43,45].…”

Effect of target–substrate distance onto the nanostructured rhodium thin films via PLD technique

“…1. The tight focusing of the high power laser beam onto the target was avoided as it leads to the formation of liquid droplet which develops microstructures and craters onto the film surface (Mostako et al 2011). The micrograph of single shot laser spot onto the photographic paper is shown in the Fig.…”

Note: Epitaxial ruby thin film based photonic sensor for temperature measurement

“…9 Pulsed laser deposition (PLD) is another simple technique for the deposition of high quality crystalline thin film of various oxides and heavy metals. [13][14][15][16] In the present note growth of epitaxial ruby thin film on sapphire substrate is presented via PLD. The deposited film was subjected to temperature dependent photoluminescence (PL) studies and shown to act as linear temperature sensor in low temperature range.…”