Radiochromic gel dosemeter for three-dimensional dosimetry

A gel dosemeter in which ionising radiation causes a colour change was produced by modifying an existing Fricke gel system. This allows a more convenient preparation procedure and gives a better quality dosimetric system for three-dimensional (3-D) dose measurements. The role of three active components of the Ferrous sulphate Xylenol orange Gelatin (FXG) gel dosemeter is quantified with special consideration of their effect on system sensitivity and stability. The optimal composition was found to be 0.5 mM ferrous sulphate, 0.1 mM xylenol orange and 25 mM sulphuric acid. The dose response is linear in the range 0.1-30 Gy. The FXG sensitivity, derived from the gradient of the dose response curve, was found to be DeltaA = 0.084 cm(-1) Gy(-1), where A is the optical absorption coefficient at a wavelength of 585 nm, with reproducibility and 24 h stability of better than 5%. (C) 2001 Elsevier Science Ltd. All rights reserved.