[en] A 55 Mjoules Magnet has been installed and commissioned at CERN for the Rapid Cycling Bubble Chamber of the EHS experiment (European Hybrid Spectrometer). The magnet consists of two separate circular coils, assembled with their axis horizontal into a massive iron structure, and provides a central field of 3 T in a useful volume of 1.4 m in diameter and 0.82 m gap with a completely azimuthally free acceptance of +-18 deg from the central plane. Special features of the magnet, which is otherwise of a classical pancake-type, bath-cooled design, are a relatively high average current density (2500 Amp/cm²) and an elaborate support structure required by the particular force configuration within the iron structure

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No abstract available

[en] A bubble chamber with golographic data read out designed for the investigation of short-lived particles with a life time of 10^-12-10^-13 s and a free path about 0.5 mm has been described. The aim of the invention is to remove vessel vibration, to increase the chamber volume utilization factor, and to simplify the chamber vessel design. These aims are achieved by means of inroduction of the additional displacer into the chamber containing a vessel with working fluid, expansion system, heat exchanger, and golographic system. The expansion system is accomplished in a form of two movable elements placed symmetric about each other. The displacer is situated between them, and the heat exchanger is situated on the displacer external surface. The expansion system axis is directly above the golographic axis and is parallel to the latter. The above chamber design has essential advantages as compared to known designs. The chamber vessel is free from vibration, that allows one to increase the accuracy of event unfolding from obtained holograms. The chamber vessel is easy in fabrication. The chamber volume utilization factor is K=0.7 (almost the whole chamber volume is useful). Besides, a decrease of the design metallic elements permits to increase the information accumulation rate at the expense of the growth of chamber response frequency

[en] Methods are presented of forming external (loaded) heads of sensitive vessels of liquid-hydrogen targets with a 'cold punch' method as well as internal (limiting) heads with a hot drawing method. Polyethyleneterephthalic film has been used as a raw material

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No abstract available

No abstract available

[en] Targets with so-called passive expansion of medium in the target are used in known bubble chambers operating together with a track-sensitive target placed in the chamber volume. Such expansion method is realized only at the expense of the deflection of thin target walls during the pressure drop in the chamber. A design of an expansion device for the track-sensitive target containing hydrogen is considered. The device of the membrane type provides, at equal initial pressures in the chamber and target, in each expansion cycle an additional reduction of end pressure in the target to 0.3 atm relative to the chamber pressure. The device does not need an autonomous drive. Complete membrane travel is 2.0 mm. The travel is controlled remotely in some range which permits to reach the regime of synchronous tracksensitivity of medium-detectors in the chamber and target. Working models of the device were tested during the irradiation of a Ludmila device together with inner track-sensitive target in the regime of filling of chamber and target volumes with liquid hydrogen. The test results are recognized quite satisfactorily

[en] The design features and characteristics of a magnetic collimator with moving d.c. magnetized plates are described. The effect of scattering field gradients in the collimator working area on a beam of particles in a magnet channel, of the electromagnet coil temperature mode together with the analysis of the electromagnet thermal equilibrium in the collimator vacuum chamber is estimated. The corresponding experimental data are also presented. It is pointed out that the collimator operation at the channel of separated particles of liquid-hydrogen bubble chamber ''LUDMILA'' show its sufficient operating reliability and convenience. With magnetic collimators switched in the background in the LUDMILA chamber is about 50% less