Title: X-ray transmission through photonic crystal fibers
by: Paul Klenk
Abstract:
Photonic crystal fibers (PCF), developed originally for the fiber optics industry
are glass capillary fiber optics in which the inner glass core is surrounded by longitudinal
holes designed to reduce transmission losses. This research examines the possibility of
using the longitudinal holes in PCF for the transmission of soft x-rays (<20 keV) through
grazing incidence reflection.
Such a fiber for x-ray transmission could allow the
construction of a flexible instrument for the delivery of precisely directed radiation
therapy. A bundle of such fibers could deliver a small, highly collimated beam of
therapeutic, low energy (<20 keV) x-rays along flexible, curved paths. These therapeutic
x-ray beams would be of closely controlled size, from diameters as small as a few
microns up to centimeters depending on the number of fibers in the bundle. For radiation
to be transmitted along a flexible, curved path the x-ray energies are limited to the low
energy x-ray regime (<20 keV) and consequently this x-ray radiation is absorbed strongly
in tissue. Thus, the majority of radiation would be absorbed by the tumor, and not pass
through to underlying healthy tissue. This is also a disadvantage because the treatment
would be limited to surface treatments on the order of a few millimeters. Initial modeling
results of x-ray transmission through curved capillaries will be presented as well as initial
experimental results for the transmission of x-rays through curved PCF.