Thesis (Ph. D.)--University of Wisconsin--Madison, 1956. / Typescript. Abstracted in Dissertation abstracts, v. 17 (1957) no. 5, p. 1098-1099. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 57).

[No abstract available] / Science, Faculty of / Physics and Astronomy, Department of / Graduate

A high-frequency discharge ion source was developed yielding 45% protons in an 800 microampere, 14 kv energy focused beam of positive hydrogen ions. Higher ion currents could be delivered at higher voltages. The discharge was excited in a pyrex discharge tube, 1¼ inches in diameter and 9 inches long, by a 210 Mc/sec. push-pull, oscillator capable of delivering 120 watts power. An electrostatic potential difference of 1.8 kv applied axially with the discharge tube, accelerated the positive ions formed in the discharge toward the exit canal. A magnetic field of 240 gauss, also applied axially, shaped the discharge conically, and intensified the redness of the discharge, causing the Balmer lines to appear prominently when the discharge was viewed through a spectroscope. The ions emerging from the exit canal were focused by an electrostatic lens using a potential difference of 12 kv. The hydrogen pressure in the discharge tube measured 17 microns, and the rate of hydrogen consumption measured 11 cc. per hr. The proton percentage was found to depend on the oscillator power and critically on the gas pressure. The magnetic field increased the proton percentage, but in an unpredictable manner. It was also found that the focusing lens in front of the probe canal exerted an extracting action on the ions in the discharge; influencing very strongly the total ion beam current collected. The general performance of the ion source was found to be satisfactory. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Reignition curves have been obtained for a high current (40ka) spark gap channel in air at atmospheric pressure at various radial distances down to delay times of 50 µs. after initiation of spark. The reignition curves in the ‘thermal breakdown' regime are obtained by a constant voltage generator having a variable output ranging from 100 volts to 2.5 kv, while those in the 'spark breakdown' regime are obtained by the use of a restriking voltage generator having a higher voltage output ranging from 1 kv to 15 kv. The experimental results show that the gas at large radial distances recovers faster than that at a smaller distance. A special feature of the recovery curves is the occurrence of a dip which is thought to be the effect of a thermal wave. Gas temperatures are derived by using the equation of state, Paschen curves and the reignition measurements. A temperature profile of the spark channel has been obtained which indicates that the spark channel has a fairly uniform temperature up to a radial distance of 2.5 cm. Beyond this distance the temperature drops rapidly to ambient temperature at a radial distance of 4 cm, Deionization and recovery mechanisms are predicted theoretically and are verified during the earlier recovery period in which 'thermal breakdown' occurs and during the later recovery period when 'spark breakdown' is observed. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The glow phase of high pressure spark discharges initiated by the Townsend mechanism of breakdown in hydrogen, nitrogen and carbon dioxide is studied using 16 ohm coaxial cable discharge techniques. Before the establishment of the spark channel in these low over-voltaged spark discharges, there exist two distinct transition stages, namely, a diffuse glow phase and a filamentary glow-to-channel transition phase. The optical appearance of the diffuse glow is similar to that of a normal d.c. glow discharge. It consists of a negative glow, a Faraday dark space, and a positive column. From our experimental results it is concluded that for the glow phase the cathode fall voltage and the ratio of the axial potential gradient to the gas pressure in the positive column are fixed for each gas. These values are independent of the impedance of the external circuit and the gas pressure. Comparisons with low pressure d.c. glow discharges indicate further that the cathode fall voltages are in agreement in both types of glow for the gases' investigated. In addition, a qualitative discussion about the transition nature of this diffuse glow phase is given on the basis of results obtained from spectroscopic investigations. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

No description available.

No description available.

Thesis (Ph. D.)--University of Chicago, 1913. / "Reprinted from the Physical review, vol. XXXIV, no. 2, February 1912."

Thesis (Ph. D.)--University of Chicago, 1916. / "A private edition distributed by the University of Chicago libraries." "Reprinted from the Physical review, n.s., vol. VIII, no. 6, December, 1916." Bibliography: p. 650.

Major part of Thesis (PH. D.)--University of Michigan, 1941. / An article, by R.B. Randels, K.T. Chao and H.R. Crane, reprinted from the Phyusical review, v. 68, nos. 3-4, August 1-15, 1945. Includes bibliographical references.