title: Effect of perchloric acid on the performance of the Fricke xylenol gel dosimeter.
abstract: The conventional ferrous xylenol orange (XO) gel (FXG) dosimeter is being wildly investigated for radiotherapy dose measurements. Upon irradiation, its color turns red due to oxidation of Fe(2+) into Fe(3+), which forms a complex with xylenol orange. The effect of perchloric acid (PCA) on the dosimetric properties of the gel in the dose range of 1-15Gy was investigated using visual spectrophotometry. FXG-PCA responds to radiation dose linearly and exhibits higher radiation sensitivity than the conventional gel dosimeter. PCA in a concentration of 20mM enhances the radiation sensitivity ~44%. Stability of the absorbances of both the gels during storage under various conditions was investigated, and the uncertainty of dose measurements was estimated.
authors.affiliation: Biophysics Branch, Physics Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.
authors.forename: M I
authors.initials: MI
authors.lastname: El Gohary
authors.affiliation: National Center for Radiation Research and Technology, Atomic Energy Authority (AEA), P. O. Box 8029, Nasr City, Cairo, Egypt. Electronic address: yasser_shabaan@hotmail.com.
authors.forename: Y S
authors.initials: YS
authors.lastname: Soliman
authors.affiliation: Medical Physics Unit, Ain-Shams Hospital, Ain-Shams University, El Abbasia, Cairo, Egypt.
authors.forename: E A
authors.initials: EA
authors.lastname: Amin
authors.affiliation: Biophysics Branch, Physics Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.
authors.forename: M H Abdel
authors.initials: MH
authors.lastname: Gawad
authors.affiliation: National Center for Radiation Research and Technology, Atomic Energy Authority (AEA), P. O. Box 8029, Nasr City, Cairo, Egypt.
authors.forename: O S
authors.initials: OS
authors.lastname: Desouky
mesh_terms: D005296:Ferrous Compounds; D005782:Gels; D006801:Humans; D010472:Perchlorates; D010636:Phenols; D000072232:Radiation Dosimeters; D011879:Radiotherapy Dosage; D012996:Solutions; D013053:Spectrophotometry; D013454:Sulfoxides
chemical_list: D005296:Ferrous Compounds; C075364:Fricke solution; D005782:Gels; D010472:Perchlorates; D010636:Phenols; D012996:Solutions; D013454:Sulfoxides; C016833:xylenol orange; C576518:Perchloric Acid
keywords: Dosimetry; Radiochromic gel; Radiotherapy