Date of Award
Doctor of Philosophy
Dr. John A. Tanis
Dr. Emanuel Y. Kamber
Dr. Asghar N. Kayani
Dr. Nikolaus Stolterfoht
Glass capillaries, fast, highly charged ions, insulators, tandem accelerator, oxygen ions, protons
Transmission of fast highly charged ions through insulating single straight cylindrically-shaped and tapered funnel-shaped glass capillaries of microscopic dimensions has been studied using MeV/u proton and oxygen beams. The beams, obtained from the WMU tandem Van de Graaff accelerator, were transmitted through the capillaries and then counted with a silicon surface barrier detector.
The interaction between 1 and 3 MeV protons and 12, 16 and 24 MeV O5+ ions and the inner walls of the straight and tapered glass capillaries was investigated by measuring the transmission energy dependence. The straight capillaries had diameters of 0.18 and 0.14 mm and lengths of 14.4 and 11.2 mm, respectively, for an aspect ratio of 80 for both samples. The tapered capillary had an inlet diameter of 0.71 mm, an outlet diameter of 0.1 mm and a length of 28 mm for an outlet to inlet area ratio of 20x10-3. The obtained data were reproducible for the energies used and the results indicate that the incident ions traverse the capillaries without significant energy loss. The transmission dependence on the incident charge state was examined using 16 MeV O5+ to O8+ ions on the tapered capillary. The results obtained show that the incident charge state has the maximum transmission through both capillaries with the existence of small fractions of ions (< 1%) that capture an electron or lose one, two or three electrons.
Ayyad, Asmaa Mohammed, "Interaction of Fast Highly Charged Ions with Insulating Straight and Tapered Glass Capillary Surfaces" (2013). Dissertations. 195.