LiF and CaF2: Dy thermoluminescent dosimeters

Area of Science:

• Solid State Physics
• Radiation Detection and Measurement

Background:

• Thermoluminescence (TL) materials like LiF and CaF2:Dy are crucial for radiation dosimetry.
• Understanding glow curve characteristics is essential for accurate dose assessment.

Purpose of the Study:

• To investigate the influence of annealing temperature and time on LiF glow curve characteristics.
• To compare different annealing methods for LiF and their effect on glow curve shape.
• To evaluate the sensitivity and response of LiF (TLD-100, -600, -700) and CaF2:Dy to 60Co gamma rays.

Main Methods:

• Studied LiF glow curve properties under varying annealing conditions (temperature, time, hot air stream).
• Compared the thermoluminescent response of LiF TLD-600, TLD-100, and TLD-700 to 60Co gamma radiation.
• Examined the glow curves and relative response of CaF2:Dy.

Main Results:

• Annealing method significantly affects LiF glow curve shape; hot air stream allows for rapid annealing.
• Fading is minimal for LiF when annealing and measurement times are constant, except for long-term personnel dosimetry.
• LiF TLD-600 demonstrated 1.23 times higher sensitivity to 60Co gamma rays than TLD-100 and TLD-700.
• CaF2:Dy produced unusual glow curves with a significantly greater relative response compared to standard phosphors.

Conclusions:

• Annealing parameters critically influence thermoluminescent detector performance.
• LiF TLD-600 offers superior sensitivity for 60Co gamma dosimetry applications.
• CaF2:Dy presents unique thermoluminescent properties warranting further investigation for specialized dosimetry.