Four-gap glass RPC as a candidate to a large area thin time-of-flight detector

A four-gap glass RPC with 0.3mm gap size was tested with hadron beam as a time-of-flight detector having a time resolution of ~ 100ps. A thickness of the detector together with front-end electronics is ~ 12mm. Results on time resolution dependently on a pad size are presented. This paper contains first result on the timing RPC (with ~ 100ps resolution) having a strip read-out. Study has been done within the HARP experiment (CERN-PS214) R&D work. A obtaned data can be useful if a design of a large area thin timing detector has to be done.Comment: 18 pages, 13 figure

Ion implantation in polymers: chemical aspects

The review summarizes results of the investigations on the nature of chemical processes occurring in the polymer matrix under ion bombardment and the role of these processes in modification of electrical and optical properties of ionimplanted polymers. The fate of the implanted species, structure of ionimplanted layer and possible microelectronic applications of ion-implanted polymers are also discussed

Lignosulfonate, anionic surfactants and their mixtures influence on water solutions surface tension and zinc concentrate pressure leaching

The formation of elemental sulfur during sulfide concentrate pressure leaching leads to the appearance of sulfur-sulfide granules, which significantly reduces zinc dissolution rate. The solution for this problem was the use of surfactants, which prevents the negative effect of molten sulfur, avoiding the granule formation during leaching. Lignosulfonates (waste from the woodworking industry) are most often used as reagents for sulfide concentrate pressure leaching. Influence of individual and mixtures of surfactants on surface tension of aqueous solutions, zinc extraction and size-grade distribution of cakes after sulfide zinc concentrate pressure leaching. Surface tension of aqueous solutions was analyzed by stalagmometric method. Leaching was performed in titanium autoclave in presence of lignosulfonate, sodium dodecylbenzenesulfonate and sodium dodecylsulfate. Solutions after leaching were analyzed on zinc by atomic absorption spectroscopy. Size-grade analysis of cakes after leaching was carried out by laser diffraction particle size analyzer. In this work, synergetic influence was observed of anionic surfactants and lignosulfonate on decreasing of aqueous solutions surface tension. The best results were obtained when LS-SDBS mixture was used, namely in the range of sodium dodecylbenzenesulfonate concentrations 400-600 mg / l. Usage of combined surfactants allowed to achieve high rates of zinc extraction and optimal particle size of cakes after leaching. At Ls and SDBS using zinc extraction was increased from 77,2 % up to 82,8 %, with the bulk of the cake (96,7%) having a particle size of-150 μm. Combined surfactants usage (lignosulfonate and sodium dodecylbenzenesulfonate) can be recommended for applying at pressure leaching of sulfide zinc concentrates. © Published under licence by IOP Publishing Ltd.Leaching experiments and grade size analysis were conducted at the expense of the Russian Science Foundation grant (project No. 18-19-00186)

Electroless deposition and Electroplating of Metals

The present paper summarizes the main results of the research on the electroless and electrochemical metal deposition from aqueous solutions, which has been carried out in the Research Institute of Physical-Chemical problems of the Belarussian State University and at the Department of Inorganic Chemistry of the BSU for the last three decades. The paper covers the following problems: the main peculiarities of electroless and electrochemical deposition of copper, nickel, Ni-B,Ni-P, gold films 0.1-30 mkm and more in thickness, their phase composition, morphology and properties; the characteristic features of of hydrometallurgic allowing (e.g. electroless and electrochemical deposition of a number of binary alloy coatings such as Cu-Ni, Cu-Cd, Cu-Sn, Cu-Zn, Ni-Sn, Ni-W, Ni-Mo), methods of their chemical and phase composition and microstructure regulation, together with correlation between these parameters and alloy properties; the methods for composite metal and alloy film plating from solutions with production of materials including metal oxides and thus possessing unusual and useful properties; the peculiarities of metal film plating onto dielectrics with production of continuous films and metal conductive patterns without the use of photoresists

RPC with low-resistive phosphate glass electrodes as a candidate for the CBM TOF

Usage of electrodes made of glass with low bulk resistivity seems to be a promising way to adapt the Resistive Plate Chambers (RPC) to the high-rate environment of the upcoming CBM experiment. A pilot four-gap RPC sample with electrodes made of phosphate glass, which has bulk resistivity in the order of 10^10 Ohm cm, has been studied with MIP beam for TOF applications. The tests have yielded satisfactory results: the efficiency remains above 95% and the time resolution stays within 120 ps up to the particle rate of 18 kHz/cm2. The increase in rate from 2.25 to 18 kHz/cm2 leads to an increase of estimated "tails" fraction in the time spectrum from 1.5% to 4%.Comment: 8 pages, 6 figures, submitted to Elsevier Scienc