Development of flexible long lived carbon stripper foils

We have developed flexible long-lived carbon stripper foils of about 10 μg/cm2 in thickness with an enhanced carbon arc-discharge method. The foils are not only mechanically strong, but also long-lived against the bombardment of a 3.2-Mev Ne ion beam of 1 μA in intensity with a beam spot of 3.5 mm in diameter. The average lifetime is 15 h. This value is about 30 times longer than those of commercially available foils. We have found the areas of the foils under the heavy ion bombardment to change their crystal structure. An inspection by means of an electron microscope shows that the nature of the area has transformed to a crystallographic characteristic from amorphous crystals. (orig.)