Thermoluminescent response of TLD-100 to low energy electrons (5 keV to 30 keV) and the effect of annealing in various atmospheres
Previous investigations of the thermoluminescent response of the dosimetry phosphor LiF (TLD-100) to low energy electrons have given veried estimates of its sensitivity. In addition, several investigators have noted that the glow curve shape of TLD-100 irradiated with low energy electrons differs from that obtained after irradiation with /sup 137/Cs gamma rays or high energy electrons. The work reported for single crystal TLD-100 yields the following main conclusions: (1) If annealings are done carefully in vacuum, then the sensitivity of TLD-100 single crystals to 5 to 30 keV electrons and the resultant glow curve is essentially the same as when irradiations are carried out with /sup 137/Cs gamma rays. (2) All discrepancies in sensitivity can be accounted for by the higher Linear Energy-Transfer (LET) of the electrons. (3) The ''standard annealing'' of 400/sup 0/C for one hour commonly used, produced a change in the glow curve shape and a loss in sensitivity in contrast to the vacuum anneal results. Diffusion of hydroxyl ions into the sample during air annealing was isolated as the primary cause for this change. (4) These results also explain the cause for the existence of the 0.4 micron ''dead layer'' which previous investigators have proposed to explain the variation with particle size of the luminescent efficiency of TLD-100 powder irradiated with x-rays. The glow curve obtained from virgin TLD-100 extruded ribbon samples varied, but in general lay between the glow curve obtained from single crystal samples annealed in vacuum and single crystal samples annealed in air. With the use of the annealing procedure presented TLD-100 may immediately be applied to the dosimetry of low energy electrons and other shallowly penetrating radiation. With this proposed annealing procedure the same sensitivity and reproducibility can be achieved as is currently achieved for the dosimetry of x-rays.
- Research Organization:
- Wisconsin Univ., Madison (USA). Medical Physics Labs.
- DOE Contract Number:
- EY-76-S-02-1105
- OSTI ID:
- 7143266
- Report Number(s):
- COO-1105-234; TRN: 77-012038
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ELECTRON DOSIMETRY
THERMOLUMINESCENT DOSEMETERS
ANNEALING
SENSITIVITY
ATMOSPHERES
GLOW CURVE
KEV RANGE 01-10
KEV RANGE 10-100
LET
LITHIUM FLUORIDES
ALKALI METAL COMPOUNDS
DOSEMETERS
DOSIMETRY
ENERGY RANGE
ENERGY TRANSFER
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HEAT TREATMENTS
KEV RANGE
LITHIUM COMPOUNDS
LITHIUM HALIDES
LUMINESCENT DOSEMETERS
MEASURING INSTRUMENTS
440102* - Radiation Instrumentation- Radiation Dosemeters