Search results for "Electroplating"
showing 9 items of 19 documents
An ion guide for the production of a low energy ion beam of daughter products of α-emitters
2006
A new ion guide has been modeled and tested for the production of a low energy ($\approx$ 40 kV) ion beam of daughter products of alpha-emitting isotopes. The guide is designed to evacuate daughter recoils originating from the $\alpha$-decay of a $^{233}$U source. The source is electroplated onto stainless steel strips and mounted along the inner walls of an ion guide chamber. A combination of electric fields and helium gas flow transport the ions through an exit hole for injection into a mass separator. Ion guide efficiencies for the extraction of $^{229}$Th$^{+}$ (0.06%), $^{221}$Fr$^{+}$ (6%), and $^{217}$At$^{+}$ (6%) beams have been measured. A detailed study of the electric field and …
Multi-technique characterization of gold electroplating on silver substrates for cultural heritage applications
2017
Proceedings of the 12th European Conference on Accelerators in Applied Research and Technology (ECAART12).-- et al.
Proton beam written hydrogen silsesquioxane (HSQ) nanostructures for Nickel electroplating
2009
Abstract Hydrogen silsesquioxane (HSQ) behaves as a negative resist under MeV proton beam exposure. HSQ is a high-resolution resist suitable for production of tall ( 1.5 μ m ) high-aspect-ratio nanostructures with dimensions down to 22 nm. High-aspect-ratio HSQ structures are required in many applications, e.g. nanofluidics, biomedical research, etc. Since P-beam writing is a direct and hence slow process, it is beneficiary to fabricate a reverse image of the patterns in a metallic stamp, e.g. by Ni electroplating. The Ni stamp can then be used to produce multiple copies of the same pattern. In this study we investigate the possibility to produce Ni stamps from p-beam written HSQ samples. H…
X-Ray microcalorimeter detectors - Technology developments for high energy astrophysics space missions
2020
Improvements in the design, fabrication, and performance of astronomical detectors has ushered in the so-called era of multi messenger astrophysics, in which several different signals (electromagnetic waves, gravitational waves, neutrinos, cosmic rays) are processed to obtain detailed descriptions of their sources. Soft x-ray instrumentation has been developed in the last decades and used on board numerous space missions. This has allowed a deep understanding of several physical phenomena taking place in astrophysical sources of different scales from normal stars to galaxy clusters and huge black holes. On the other hand, imaging and spectral capabilities in the the hard x-rays are still la…
Experimental investigation and modelling for sulphuric acid recovery by diffusion dialysis
2018
Sulphuric acid is known to be one of the key inorganic acid and has been widely used in chemical reaction and metal industries for surface treatments as in the copper electroplating process. During these processes, large amounts of waste sulphuric acid solution are generally generated, containing high concentrations of metals and acid. The possibility of recover and reuse the sulphuric acid in the process could avoid environmental contamination and reduce costs of the disposal. Among several separation methods, diffusion dialysis (DD) is becoming more and more attractive thanks to the recent important advances in ion exchange membranes (IEMs) field and because of its clean nature and operat…
Diffusion dialysis for the treatment of H2SO4-CuSO4 solutions from electroplating plants: Ions membrane transport characterization and modelling
2021
Diffusion dialysis (DD) is proposed to separate and recover mineral acids and transition metals from electroplating industry process waters promoting a circular approach of resources recovery. In this work, a DD module with two anionic membranes (Fumasep FAD and Neosepta AFN) are used for the separation of H2SO4 from Cu2+ containing solutions. The membrane performances with sole H2SO4 solutions (0.2–2 M) and sole CuSO4 solutions (0.8–1.1 M Cu2+) and with mixtures of H2SO4 (0.6 M) and CuSO4 (0.2–1.1 M Cu2+) as feed are studied. H2SO4 recovery efficiency decreases as the concentration of acid increases. For H2SO4 solutions, the water drag flux from the retentate to the diffusate prevails agai…
Reconsidering the accuracy of X-ray fluorescence and ion beam based methods when used to measure the thickness of ancient gildings
2017
Since at least 5000 years ago, gilding techniques have been used for decoration purposes or to make artefacts appear as made of solid gold. Investigation of ancient gildings inevitably requires measuring their thickness, which is usually done either through the observation of cross-sections or by methods such as Rutherford backscattering spectroscopy, particle-induced X-ray emission and X-ray fluorescence. Whereas the former method requires sampling, the latter ones are non-invasive and therefore preferable. These non-invasive methods, however, measure the number of atoms per unit area, which can be converted into thickness only if the density is known. So far this has not been considered a…
Electroplated Indium Bumps as Thermal and Electrical Connections of NTD-Ge Sensors for the Fabrication of Microcalorimeter Arrays
2012
We are developing a method to build arrays of Ge-based microcalorimeters for soft X-rays detection using micro-photolithographic techniques. A key element of the process is the electrical and thermal connection between the germanium sensors and the interconnection electrical tracks, that lay on a substrate acting as mechanical support and thermal sink. The geometry of the sensors, that have a square base truncated pyramid shape, makes feasible a connection through indium soldering. We describe a technique, based on microlithography and electroplating, adopted to grow indium bumps of a few tens of square microns of area and several microns high on top of the contact pads patterned on the sub…
A new application for nickel foam in alkaline fuel cells
2009
The use of nickel foam as an electrode substrate in alkaline fuel cells (AFCs) has been investigated for bi-polar cells incorporating an electrically conducting gas diffusion layer. This contribution focuses on the cathode, and draws comparisons between nickel foam and nickel mesh substrates. One of the principal electrocatalysts for the cathodic reduction of oxygen is silver, so an improvement in electrochemical performance was obtained by electroplating the nickel foam with silver. The electrodeposition process was optimised to maximise electrochemical performance with a minimum of silver deposited. Nickel foam, which is less expensive than the usual nickel mesh, appears to be a good subs…