الفهرس 
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Abstract
A complete study of the characteristics of a glow discharge ion source has been made. this ion source is needed for ion etching of metals and insulations to be investigated by Seville electrode microscope, and ion thinning of specimens for transmission electron microscope to reveal their structure.
to begin with the discharge characteristics has been investigated for hydrogen, nitrogen and argon gases. Although the discharge characteristics of’ these gases have the same shape, however, they differ in the fence that a certain tube current can only be obtained by changing the tube voltage for each gas used.
The ion beam current increases as the tube current increases, and depends on the gas pressure which has optimum for maximum ion beam current. this optimum gas pressure varies from one gas to another. Gases of the order of 18, 8.5, 8 mA/cm2 have been obtained respectively.
The ion energy analysis has also been studied; the energy spectrum has two peaks one at high energy and the other at low energy this is due to the symmetrical charge exchange.