The biological effects of charged particles is of interest in particle therapy,
radiation protection and space radiation science and known to be dependent on both
absorbed dose and radiation quality or LET. Microdosimetry is a technique which uses a
tissue equivalent gas to simulate microscopic tissue sites of the order of cellular
dimensions and the principles of gas ionization devices to measure deposited energy.
The Gas Electron Multiplier (GEM) has been used since 1997 for tracking particles and
for the determination of particle energy. In general, the GEM detector works in either
tracking or energy deposition mode. The instrument proposed here is a combination of
both, for the purpose of determining the energy deposition in simulated microscopic
sites over the charged particle range and in particular at the end of the range where
local energy deposition increases in the so‐called Bragg‐peak region. The detector is
designed to track particles of various energies for 5 cm in one dimension, while
providing the particle energy deposition every 0.5 cm of its track. The reconfiguration of
the detector for different particle energies is very simple and achieved by adjusting the
pressure of the gas inside the detector and resistor chain. In this manner, the detector
can be used to study various ion beams and their dose distributions to tissues. Initial
work is being carried out using an isotopic source of alpha particles and this thesis will
describe the construction of the GEM‐based detector, computer modelling of the
expected gas‐gain and performance of the device as well as comparisons with
experimentally measured data of segmented energy deposition. / UOIT
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OOSHDU.10155/293 |
| Date | 01 December 2012 |
| Creators | Sipaj, Andrej |
| Contributors | Waker, Anthony |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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