LiF:W as a scintillator for dosimetry in diagnostic radiology

The use of ionization chambers in diagnostic radiology is not feasible in measurement situations requiring small and robust dose sensors. The composition of LiF:W developed as a scintillator for the measurement of thermal neutrons seems profitable for an application in dosimetry of low-energy photons. Properties of a small LiF:W scintillator were determined with DV- and DH-standard radiation qualities. For a tube voltage range of 40 to 150 kV (corresponding to a HVL of 1.56 to 13.69 mm Al) a maximum variation in sensitivity of +/-13% was determined for a scintillator thickness of 3.7 mm. The scintillator signal was linear in a range from 6.6 mGy min(-1) to at least 13.7 Gy min(-1). Higher dose rates could not be obtained in the measurement setup. The temperature dependence of the luminescence response was found to decrease from +3.7% (at +2.5 degrees C) to -7.0% (at +45 degrees C) with respect to the luminescence response at 20 degrees C. LiF:W appears to be an interesting choice as a dosimetric scintillator in diagnostic radiology making immediate measurements of dose and dose rate with high spatial resolution feasible.