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This investigation was to study the response of
thermoluminescent material CaF2:Tm phosphor (TLD-300) to
protons. The sourse of proton beam was produced by a Van de
Graaff accelerator with an energy range between 0.7 to 3.0 MeV.
There are two kinds of anneal- ing procedures for TLD-300: one
is 830 ℃ or 90 min, the other 400 ℃ for 90 min. There are two
glow peaks for the high temperature treatment and three for the
low temperature treatment. The peaks' positions ( Tm ) of the
glow curve depend on proton energy. The proton energy was
investigated by studying the peak height ratio (Hi/Hf) of the
glow curve, and the thermolum- inescent efficiency (Hi/TL) of
the glow-peak as well. The thermoluminescent parameters of the
glow peaks for CaF2:Tm dosimeters were analyzed experimentally
by using initial rise and glow curve shape analysis (GCS)
methods. The following are the results: 1. The glow-curve
distribution can be distinguished between proton and gamma
radiation. 2. The proton energy can be determined by the
calibration curves of the Hi/Hf or Hi/TL. 3. The activation
energies of Co(60) gamma-ray irradiated TLD-300 were 1.09 and
1.86 eV. The kinetic orders were 1 and 2 for the third and
fifth peak respectively, which were determined by the GCS
method. When the GCS method was applied in the proton-
irradiated TLD-300, the fifth peak only could be determined
with an activation energy of 1.78 eV and kinetic order of 2.
The use of initial rise method for the determination of
activation energies for the three main peaks, one can obtain
the three energies as 1.95, 2.38 and 2.75 eV.
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