One of the primary concerns with space travel is the protection of astronauts
from potentially lethal radiation. A major source of potentially lethal radiation is our
own sun. During Solar Cycle 23 there were 97 detected Solar Particle Events (SPEs). In
order to develop radiation protection guidelines and establish methods to protect
astronauts the spectrum of particles emitted during a SPE must be understood.
Data for oxygen and iron particle fluence was taken from the Solar Isotope
Spectrometer. The fluence was sorted and formatted for each solar particle event. After
determining the contribution to skin dose for oxygen, the time evolution of each event
was analyzed. After analyzing the raw count data, a threshold was set that could be
applied to each event. Using this threshold count rate as the starting point, each event
was plotted and fitted with a smoothing polynomial function. The slope calculated from
this function was then plotted against the previously calculated skin dose and a Weibull
function was fitted to the data. The resulting plot provides a method to predict the
cumulative dose due to the oxygen fluence over the first 24 hours of an event and thereby provide a warning of future high dose rate in time to achieve significant dose
sparing for most events. For the ten events that delivered the highest oxygen dose, the
dose sparing that could be achieved by taking shelter when the high dose rate was
predicted was greater than 70 percent for all but one event. The one outlier achieved a
dose paring of only 57 percent.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-05-275 |
| Date | 16 January 2010 |
| Creators | Hill, Marcus |
| Contributors | Braby, Leslie A. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis |
| Format | application/pdf |
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