G(Fe3+) values in the FBX dosimeter at low dose-rates

Gupta, B.L.; Madhvanath, U.

doi:10.1016/0020-708x(85)90261-3

Cited by 10 publications

(9 citation statements)

References 5 publications

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“…This is in good agreement with the high sensitivity reported for the FBX dosimeter (Gupta and Narayan 1985). However, Gambarini et al (1994) found no enhancement of sensitivity when benzoic acid was incorporated into an oxygenated agarose gel, and there are no reports available on the effects of this additive on the sensitivity of gelatine gels.…”

Section: Introductionsupporting

confidence: 83%

Measurement of Output Signals from an Avalanche Photodiode by Irradiating with X-rays in the Temperature Range from 150 mK to 4.2 K

Yasumune

Masuda

Oshima

et al. 2011

Jpn. J. Appl. Phys.

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We measured leakage current and gain characteristics of a reverse-type avalanche photodiode (APD). The leakage current generated below the breakdown voltage was found to be lower than 1 pA at temperatures below 200 K. Avalanche multiplication of the APD was achieved in the temperature range from 150 mK to 300 K. To characterize charge carrier properties of the APD, output signal pulses from the APD were observed by irradiating the APD with X-rays in the temperature range from 150 mK to 4.2 K. The yield of signal charge was found to abruptly change in the temperature range from 1 to 2 K, where the yield of charge at 1 K is about 50% of that at 2 K.

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Section: Introductionsupporting

confidence: 83%

Measurement of Output Signals from an Avalanche Photodiode by Irradiating with X-rays in the Temperature Range from 150 mK to 4.2 K

Yasumune

Masuda

Oshima

et al. 2011

Jpn. J. Appl. Phys.

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“…The reaction completion rates of the liquid FBX dosimeter are already known. 20,24 However, our experiments indi- cated that the reaction completion rates might be quite different when the dosimeter solution is mixed with gelatin. In its liquid form, the dosimeter solution has a shelf life of ϳ14 days, showing no appreciable change in optical absorption due to oxidation during that time.…”

Section: Unirradiated Samplesmentioning

confidence: 73%

“…The radiochromic chemical solution used in this investigation was xylenol orange complexed with the ferrous ion ͑FBX͒. The radiochemistry of the FBX liquid dosimeter has been studied extensively 18,[20][21][22][23][24] and has been shown to have properties very similar to the standard liquid Fricke solution. When the ferrous ion ͑Fe 2ϩ ) is irradiated, it oxidizes to form the ferric ion ͑Fe 3ϩ ) and the corresponding complex with xylenol causes a change in absorption, which has a broad peak centered at a wavelength of 540 nm ͑Fig.…”

Section: A Fbx-gelatin Preparationmentioning

confidence: 99%

Optical CT reconstruction of 3D dose distributions using the ferrous–benzoic–xylenol (FBX) gel dosimeter

1998

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In recent years, magnetic-resonance imaging of gelatin doped with the Fricke solution has been applied to the direct measurement of three-dimensional (3D) radiation dose distributions. However, the 3D dose distribution can also be imaged more economically and efficiently using the method of optical absorption computed tomography. This is accomplished by first preparing a gelatin matrix containing a radiochromic dye and mapping the radiation-induced local change in the optical absorption coefficient. Ferrous-Benzoic-Xylenol (FBX) was the dye of choice for this investigation. The complex formed by Fe3+ and xylenol orange exhibits a linear change in optical attenuation (cm-1) with radiation dose in the range between 0 and 1000 cGy, and the local concentration of this complex can be probed using a green laser light (lambda = 543.5 nm). An optical computed tomography (CT) scanner was constructed analogous to a first-generation x-ray CT scanner, using a He-Ne laser, photodiodes, and rotation-translation stages controlled by a personal computer. The optical CT scanner itself can reconstruct attenuation coefficients to a baseline accuracy of < 2% while yielding dose images accurate to within 5% when other uncertainties are taken into account. Optical tomography is complicated by the reflection and refraction of light rays in the phantom materials, producing a blind spot in the transmission profiles which, results in a significant dose artifact in the reconstructed images. In this report we develop corrections used to reduce this artifact and yield accurate dosimetric maps. We also report the chemical reaction kinetics, the dose sensitivity and spatial resolution (< 1 mm3) obtained by optical absorption computed tomography. The article concludes with sample dose distributions produced by "cross-field" 6 MV x-ray beams, including a radiosurgery example.

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“…The natural oxidation of Fe +2 ions can be divided in natural and ionization radiation, the natural consideration aspects as: temperature variation, light intensity and influence with air [11,[21][22][23]. Both oxidations increases with the time, consequently the absorbance values also increase.…”

Section: Methodsmentioning

confidence: 99%

6 MV wedge photon beam profiles with the fricke xylenol gel dosimeter

Oliveira¹,

Calcina²,

Cavalcante³

et al. 2009

Braz. J. Phys.

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Wedged beam are often used in clinical radiotherapy to compensate missing tissues and dose gradients. In this work, the Fricke Xylenol Gel (FXG) dosimeter was used for 6 MV photons radiation wedge field profiles measurements, allowing to infer the wedge filter physical attenuation coefficient. This dosimeter is a chemical system of a Fe 3+ -Xylenol complex concentration, that when measured spectrophotometrically, the absorbance is directly proportional to the absorbed dose. From theses results one can infer that the FXG can be used also as an alternative dosimetric system for measurements of wedge filters.

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G(Fe3+) values in the FBX dosimeter at low dose-rates

Cited by 10 publications

References 5 publications

Measurement of Output Signals from an Avalanche Photodiode by Irradiating with X-rays in the Temperature Range from 150 mK to 4.2 K

Measurement of Output Signals from an Avalanche Photodiode by Irradiating with X-rays in the Temperature Range from 150 mK to 4.2 K

Optical CT reconstruction of 3D dose distributions using the ferrous–benzoic–xylenol (FBX) gel dosimeter

6 MV wedge photon beam profiles with the fricke xylenol gel dosimeter

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