Sensitivity S<sup>i</sup><sub>p</sub> is defined as the ratio of the fractional change of gas ionization current to the fractional change of gas pressure. A maximum obtainable sensitivity was calculated, S<sup>i</sup><sub>p</sub>]<sub>max</sub> = -0.309 A/B V, where A, B are constants for a given gas within a particular range of field-to-pressure ratio. Experiments were conducted to investigate the sensitivity of air and krypton under different combinations of voltage, electrode separation and primary electron source strength. A curie of tritium placed on the central portion of either electrode produced a constant initial emission current and a high sensitivity. Sensitivity could be increased by using a stronger current source, higher voltage and a larger electrode separation. Observed values of S<sup>i</sup><sub>p</sub> for high voltage at larger separation are greater than those expected even when breakdown occurs at a (pd) quite larger than the one for S<sup>i</sup><sub>p</sub>]<sub>max</sub>. The fractional pressure change, Δp/p, is independent of the initial pressure, p, and is greater for a heavier gas subject to the same acceleration, a fact which suggests the use of a heavier gas to obtain a higher fractional current change for the same sensitivity. Krypton behaves in a similar way as air in the system. Operating current level may be higher than 10⁻⁵ ampere if stronger source is used. There is a limit in the separation for a given source configuration. Further increase in S<sup>i</sup><sub>p</sub> and current level may be achieved through better design of the configuration and location of the current source between the electrodes. The fractional current change, Δi/i, depends more on Δp rather than on the initial operating pressure, p.
From the experiment performed, it appears that a gas system will perform satisfactorily as a transient velocity gauge. / M.S.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/91111 |
| Date | January 1968 |
| Creators | Huang, Hsien-Lu |
| Contributors | Electrical Engineering |
| Publisher | Virginia Polytechnic Institute |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | en_US |
| Detected Language | English |
| Type | Thesis, Text |
| Format | ix, 81, [2] leaves, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 20223462 |
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