[en] Experiments have been carried out on the total ionization by alpha particles, in pure gases and gaseous mixtures containing metastable atoms, as a function of temperature. Using a different experimental method, the results for the mean ionization energy at 300 K given by Jesse in 1953 have been confirmed to within 1 per cent. It is established that in pure gases the mean energy W required to form a pair of ions remains constant as the temperature varies from 77 to 300 K. It is shown that there is a temperature effect for W in binary gas mixtures of the type A-B containing meta-stable atoms A^* and an 'impurity' B. A systematic study is made of the change ΔW in W as a function of the temperature and of the B 'impurity' concentration in the mixtures Ne - Ar, Ne - Kr, Ne - H₂, Ne - N₂, Ne - CH₄ and He - Ar. Experiments have been carried out on a ternary gas mixture of the type A - B - C, where C is a second ionizable 'impurity' added to the binary mixture A - B; they show the existence of excited atoms B^* formed from the 'impurity' B. Finally, it is shown that the amount of metastable atoms formed in a pure gas must be very close to the number N₀ of ion pairs, and that there must exist a correlation between the number N₀ of ion pairs and the number ≅ N₀ of metastable atoms created in the pure rare gases. (author)

[en] In this paper the induced conductivity in dielectric liquids by different types of ionizing radiations is studied. This is done by measuring the induced ionization in these dielectrics using an ionization cell and a sensitive vibrating reed electrometer. The electrical conductivity and I-V characteristics are studied at various field strengths. An attempt is made in order to explain the dependence of induced conductivity on the nature of radiation in terms of Linear Energy Transfer (LET). (author)

[en] A method is provided for detecting ionization comprising allowing particles that cause ionization to contact high pressure xenon maintained at or near its critical point and measuring the amount of ionization. An apparatus is provided for detecting ionization, the apparatus comprising a vessel containing a ionizable medium, the vessel having an inlet to allow high pressure ionizable medium to enter the vessel, a means to permit particles that cause ionization of the medium to enter the vessel, an anode, a cathode, a grid and a plurality of annular field shaping rings, the field shaping rings being electrically isolated from one another, the anode, cathode, grid and field shaping rings being electrically isolated from one another in order to form an electric field between the cathode and the anode, the electric field originating at the anode and terminating at the cathode, the grid being disposed between the cathode and the anode, the field shaping rings being disposed between the cathode and the grid, the improvement comprising the medium being xenon and the vessel being maintained at a pressure of 50 to 70 atmospheres and a temperature of 0 to 30 C. 2 figs

[en] In this work we investigated the nature of the force causing recombination in ionized gases. We found that the equation of ion lost due to recombination depends on the concentration of ions. At low concentration the equation of loss is that derived using Coulomb force. However, at very high concentration the equation is modified and force deviates from pure Coulomb force. 1 tab.; 19 figs.; 22 refs

No abstract available

[en] Measurements were made of the average energy W per ion pair formed in liquid xenon by internal-conversion electrons from ²⁰⁷Bi. Voltage pulses were observed resulting from electron collection either in liquid xenon or in a gaseous mixture of argon (95 percent) and methane (5 percent). The relative pulse heights for the two materials determine the ratio of the W values. Using the known W for the gaseous mixture, a liquid-xenon W of 15.6 + - 0.3 eV was obtained. This value is considerably smaller than the gas-phase values, 21.5 or 21.9 eV. For interpretation, Platzman's energy-balance equation was adapted to liquids, assuming a conduction-band picture. Theoretical values thus calculated agree well with experiment

No abstract available

No abstract available

[en] An ionization smoke detector consisting of two electrodes defining an ionization chamber permitting entry of smoke, a radioactive source to ionize gas in the chamber and a potential difference applied across the first and second electrodes to cause an ion current to flow is described. The current is affected by entry of smoke. An auxiliary electrode is positioned in the ionization chamber between the first and second electrodes, and it is arranged to maintain or create a potential difference between the first electrode and the auxiliary electrode. The auxiliary electrode may be used for testing or for adjustment of sensitivity. A collector electrode divides the chamber into two regions with the auxiliary electrode in the outer sensing region. (U.K.)

[en] Owing to their wide variety of properties and their very large number of constituent particles, gases and vapours exhibit many interesting features. The fact that the degree of electrical dissociation of gases, along with other important parameters such as the composition, the pressure and the geometric arrangement, can be varied over broad ranges leads to an infinitely large number of observable ionization phenomena. These phenomena were studied by natural philosophers and physicists as far back as the early 19th century. The first scientific approaches to the phenomena in ionized gases are connected with such names as Crookes, Plücker and Faraday. Today, these phenomena offer many practical applications; partly already exploited for important uses in engineering, industry and everyday life, and partly still awaiting future practical use.