11.3. Passive Dosimetry 631
Table 11.3.1: Common TL dosimeters.
Material Commercial Name
LiF:Mg,Ti TLD-100
LiF:Mg,Cu,P TLD-100H
LiF:Mg,Ti TLD-600
LiF:Mg,Cu,P TLD-600H
LiF:Mg,Ti TLD-700
LiF:Mg,Cu,P TLD-700H
CaF 2 :Dy TLD-200
CaF 2 :Mn TLD-400
AlO 2 :C TLD-500
Li 2 B 4 O 7 :Mn TLD-800
CaSO 4 :Dy TLD-900
Dose Rate: TL dosimeters can not be used to measure dose rate. However,
theaveragedose rate can be estimated by dividing the absorbed dose by the
exposure time. For accurate dose rate measurements, an electronic detector is
more suitable.
Types of Radiation: There is no universal TL material that can be used
to measure dose from all types of radiation. For example, there are some
very good materials that measure dose fromγ-rays but they are not good for
neutrons. A good strategy in this case is to use a combination of materials in
the environment where different types of radiation are expected to be present.
11.3.BOpticallyStimulatedLuminescenceDosimetry
Thermal stimulation is not the only means of retrieving stored energy from materials.
There are also materials, which emit light when stimulated by light photons. These
materials, called optically stimulated luminescence or simply OSL materials, form
a new class of dosimeters with qualities much superior than the conventional TL
dosimeters. The OSL materials can store energy in the same way as TL materials
but they give off light when stimulated optically instead of thermally as in the case
of TLDs. This is a relatively new technology and was mostlyunheard of before 1992.