Radiochromic gel dosemeter for three-dimensional dosimetry

A gel dosemeter in which ionising radiation causes a colour change was prod uced by modifying an existing Fricke gel system. This allows a more conveni ent preparation procedure and gives a better quality dosimetric system for three-dimensional (3-D) dose measurements. The role of three active compone nts of the Ferrous sulphate Xylenol orange Gelatin (FXG) gel dosemeter is q uantified with special consideration of their effect on system sensitivity and stability. The optimal composition was found to be 0.5 mM ferrous sulph ate, 0.1 mM xylenol orange and 25 mM sulphuric acid. The dose response is l inear in the range 0.1-30 Gy. The FXG sensitivity, derived from the gradien t 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, w ith reproducibility and 24 h stability of better than 5%. (C) 2001 Elsevier Science Ltd. All rights reserved.