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[en] The stunning invention of the Wilson chamber in 1911 stayed almost ignored by the physicist community for more than a decade although it permitted the visualization of the track of an alpha particle as soon as 1911. The detection principle is based on the expansion of a saturated vapor that allows the visualization of a ionizing particle motion through the formation of droplets around the ions created all along the particle path. The original device was too slow (only one expansion per minute) to be used for the detection of rare events unless to operate it for months or years. A decisive step was made in the beginning of the twenties by the Japanese physicist Takeo Shimizu, working at the Cavendish Laboratory. He managed to automate the Wilson chamber and to equip it with 2 mirrors and a camera. This new generation allowed 5 expansion per second and the knowledge of the particle track orientation in space thanks to a simultaneous photography following 2 perpendicular directions. A rate of 4 shots a minute was achieved. The Wilson chamber was constantly improved during its 30 years long career and was only supplanted by the bubble chamber in the fifties. (A.C.)

[en] The scattering analysis of acoustic waves through a wave-bearing cavity containing parallel partitioning is presented. The modeled physical configuration comprises an elastic membrane-bounded expansion chamber separated by horizontal plates. The bounding wall conditions of the splitting plates can be chosen to acoustically rigid, soft or an absorbent lining. The governing boundary value problem is solved by using Mode-Matching technique. The low frequency approximation is used and validated in a low frequency regime via the Mode-Matching solution. It is seen that scattering energies and the transmission loss is significantly affected by the variations of material properties of isotropic membranes and the bounding wall conditions. The considered configuration can be opted for the reactive as well as passive control measure of sound. (paper)

[en] One of the methods to obtain information on cell proliferation kinetics of human neoplasms can be a diffusion chamber method. Cell culture is separated from recipient cells, but is affected by all the noncellular growth-stimulating factors from the recipient side. That is an advantage of the method. Several ways of qualitative estimation of neoplasm cell growth in a diffusion chamber have been developed. The analysis of the data obtained permits to conclude that the diffusion chambers can be a suitable model for studying the neoplasm growth, obtaining the data on the human neoplasm response to exposure, analysis of various factor effect, which are used in combination with the exposure

[en] A technique for and results of studying the characteristic X-ray spectrum of micropinch radiation are presented. A compact diffusion chamber of the original design has been used as a radiation detector.

[en] Some ions produced in a cavity ionization chamber diffuse to the surface of an electrode of the same polarity as their charge, and they therefore do not contribute to the signal current. An equation for the diffusion loss of ions in parallel plate ionization chambers was derived by Langevin some time ago. It has been confirmed experimentally for air at various humidities that the decrease in output current agrees precisely with values obtained from the equations. In previous papers, we have derived both exact and approximate equations for back diffusion loss of ions in cylindrical and spherical ionization chambers. In this paper, we measure saturation curves for cylindrical ionization chambers to confirm the validity of the equation After correcting for volume recombination and also for small initial recombination, experimentally obtained diffusion losses are compared with the values obtained from the equations. (authors)

[en] This article draws the story of the Wilson chamber. In the second half of the 19. century, a general trend among scientists in Great-Britain was still the observation and the imitation of nature, this romantic approach was launched by Goethe 50 years before. In 1895, Wilson as a young physicist tried to reproduce fog in laboratory. His challenge was to reduce the role of dust particles in the Aitken method: the expansion of wet-saturated air loaded with dust particles creates fog. In 1896, at the Cavendish laboratory, he discovered that ions could be very efficient 'dust particles' to condensate vapor and in 1898 he wrote that the expansion method is probably one of the most sensitive method to detect radiation emitted by radioactive materials. The Wilson chamber got a full success only from the twenties and was intensively used for 30 years in particles and nuclear physics laboratories. This detector allowed the experimental discovery of the positron, the muon and strange particles. (A.C.)

[en] In a jet pump for a nuclear reactor a slip joint is provided between the mixer and diffuser sections thereof to facilitate jet pump maintenance and to allow thermal expansion. To limit leakage flow through the slip joint to a rate below that which causes unacceptable flow induced vibration of the pump, there is provided a labyrinth seal for the slip joint in the form of a series of flow expansion chambers formed by a series of spaced grooves in the annulus of the slip joint

[en] The principles are described of the activity of expansion and diffusion cloud chambers. The possibilities are described of the determination of the properties of charged particles using cloud chambers. (M.D.)

[en] This paper presents construction of a simple cloud chamber used to detect charged particles. Three types of dimensions of the chamber have been used to observed the quality of saturated vapor and timing of the vapor to be formed. Different types of dry iced also been manipulated to overcome long and short time delay of vapor formation. Solution to some errors occurred while assembling the chamber also been discussed. The visible tracks and the pictures taken from the experimental tracks from the chamber been used to analyze the properties and the charged of the particle tracks. (author)