The dosimetric system for dose distribution of ionizing radiation

Technical Data:

Basic parameters of the readers:

a) Laboratory reader:

Readout field: 25cm2 (5x5cm2)
Resolution of the Reader: 0,2mm/px
Dosimetric range: from 25mGy up to 20Gy
Time of readout: 3 minutes
Possible TL curve recording

b) Clinical reader:

Readout field: 400cm2 20x20cm2
Resolution of the Reader: 0,2mm/px
Dosimetric range: from 500mGy up to 20Gy
Time of readout: 25 minutes

c) Scientific reader:

Interchangeable heating components (TL tab readout, TL foils readout with dimension 2,5x2,5cm2 or 4x4cm2)
Resolution: depends on lens type used (moveable camera) from 10 micrometers/pixel
Dosimetric range: from 1mGy up to 20Gy
Time of readout: from 20 s
Possible readout of light-sensitive materials

Application:

The dosimetric system consists of three types of thermoluminescence readers (Fig. 1) and thermoluminescent foils (Fig. 2). The main application of this two dimensional dosimetric system (2D TL) are dosimetric measurements of radiation fields around radiation sources and particles beam. The advantage of the 2D TL system compared to traditional methods based on TL pellets is in shortness of time of measurement. Measurements are realized with thermoluminescent foils made from phosphors LiF:Mg,Cu,P or CaSO4:Dy and high temperature polymer. The result of a TL foil readout is the matrix of the intensity of the signal. Intensity of the signal corresponds with the absorbed radiation doses.

The mapping of dose or dose rate around sources or beams are not the only possible application of the method. One of the developed readers is intended for work in dosimetry services which use dosimeters with TL pellets. If a TL pellet is placed under a special filter, it is possible to recognise whether the exposure was dynamic (dosimeter located at the human body) or static (no movement, dosimeter left in the radiation field).

More information’s are presented here.



Fig. 1 Types of the readers: a) Laboratory; b) Clinical; c) Scientific



Fig. 2 Theromoluminescent foils


Device location:

Department of Radiation Physics and Dosimetry (NZ63)