Stepan Obraztsov

The PMTs of the CMS Hadron Forward calorimeter were found to generate a large size signal when their windows were traversed by energetic charged particles. This signal, which is due to Čerenkov light production at the PMT window, could interfere with the calorimeter signal and mislead the measurements. In order to find a viable solution to this problem, the response of four different types of PMTs to muons traversing their windows at different orientations is measured at the H2 beam-line at CERN. Certain kinds of PMTs with thinner windows show significantly lower response to direct muon incidence. For the four anode PMT, a simple and powerful algorithm to identify such events and recover the PMT signal using the signals of the quadrants without window hits is also presented. For the measurement of PMT responses to Čerenkov light, the Hadron Forward calorimeter signal was mimicked by two different setups in electron beams and the PMT performances were compared with each other. Superior performance of particular PMTs was observed.

Many electrochemical processes carried out with usage of alternating current, have a lot of advantages in comparison with the effect of a direct current. Now there is a set of the literary data demonstrating that the application of alternating-current allows one to: intensify a series of electrochemical processes; lower power inputs; improve quality of conducting process; and perform in principle new processes and increase their manufacturability. The kinetics of electrochemical reactions is influenced by such parameters of a current as the form, frequency, asymmetry, and density. A brief list of processes carried out with an asymmetric alternating current of the sinusoidal form is shown. The author considers current parameters of some of them.

The influence of the flow velocity and the current density on the degree of purification of water by electrocoagulation with an alternating asymmetrical current has been studied. It has been demonstrated that under optimum conditions at pH/sub c/ 11.0-11.5 the residual metal content in the purified water drops to the level n x 10/sup -4/ g/ml; this allows its use in the practice of stripping voltammetry.

Obraztsov: Iurii Aleksandrovich! I think the most interesting topic for our dialogue might be the directions now being taken by the movies, television, and the theater, and the prospects for the development of these performing arts.

The current source of the asymmetrical quasisinusoidal shape with continuously adjustable parameters is designed: average value of a current of the greatest half-wave is 5-16 A, frequency is 20-2000 Hz, asymmetry of half-waves is 6-11. Nominal load power is to 2.5 kW. On the basis of the principle of action of a current source, the current formation modulation, realised on the original scheme of a load-carrying part, lies. Maximum peak-to-peak current ripple is not more than 30% from amplitude. With the usage of the given source the experiments on extraction of metallic gallium from dust of a gas purification were conducted. As a result of the conducted research we received metallic gallium with a degree of purity 99.9%, the degree of extraction has compounded 80-82% with alkali liquor in chambers of a diaphragm electrolytic furnace, being the load of a source. The data outcomes are obtained at current intensity 15 A, asymmetry 7-8 and frequency 461/spl plusmn/1 Hz.

A current source of asymmetrical quasi-sinusoidal shape with continuously adjustable parameters is designed: average value of a current of the maximum half-wave is 5-16 A, frequency is 20-2000 Hz, asymmetry of half-waves is 6-11. Nominal load power is 2.5 kW and maximum peak-to-peak current ripple is no more than 30% from amplitude. With the use of the given source, experiments on the extraction of metallic gallium from the dust of a gas purifier were conducted. As a result of the conducted research, we obtained metallic gallium with degree of purity 99.9%, the degree of extraction was compounded 80-82% with alkali liquor in chambers of a diaphragm electrolytic furnace which is the load of the source. The data results are obtained at a current intensity 15 A, asymmetry 7-8 and frequency 461/spl plusmn/1 Hz.