  Type I X-ray bursts and superbursts on neutron stars release sudden and
intense radiation fields into their surroundings. Here, we consider the
possible effects of these powerful explosions on the structure of the accretion
disk. The goal is to account for the apparent evolution of the innermost
regions of the accretion disk around 4U 1820-30 during a superburst. Three
different processes are considered in detail: radiatively or thermally driven
outflows, inflow due to Poynting-Robertson drag, and a structural change to the
disk by X-ray heating. Radiatively driven winds with large column densities can
be launched from the inner disk, but only for L/L_{Edd} >~ 1, which is expected
to be obtained only at the onset of the burst. Furthermore, the predicted mass
outflow rate is less than the accretion rate in 4U 1820-30. Estimates of the
Poynting-Robertson or radiative drag timescale shows that it is a very
efficient means of removing angular momentum from the gas. However, the
analytical results are likely only applicable at the innermost edge of the
disk. X-ray heating gives a change in the disk scale height that is correlated
with the blackbody temperature, as seen in the evolution during the 4U 1820-30
superburst. If this change in the scale height can alter the surface density,
then the viscous time (with \alpha ~ 0.03-0.2) is the closest match to the 4U
1820-30 results. We expect, however, that all three processes are likely
ongoing when an accretion disk is subject to a sudden heating event.
Ultimately, a numerical simulation of a disk around a bursting neutron star is
required to determine the exact response of the disk. Magnetic truncation of
the accretion flow is also considered and applied to the 4U 1820-30 X-ray
reflection results.
