The use of the Miniature Silicon Diode as a Radiation Dosemeter

Raju, M. R.

doi:10.1088/0031-9155/11/3/302

Cited by 11 publications

(2 citation statements)

References 7 publications

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“…For clinical proton beams, the need for accurate dose distribution data, such as depth dose distributions and lateral dose profiles, is as great as for other radiation qualities used in radiation therapy. Also in this case, the silicon diode detector is of interest (Raju 1966, Koehler 1967, Verhey et al 1979, Rikner et al 1983, Vatnitsky et al 1999. However, in previous work an inconsistency in the response in the Bragg peak between n-type Si diode detectors and ionization chambers has been observed but not satisfactorily explained (Verhey et al 1979).…”

Section: Introductionmentioning

confidence: 93%

General characteristics of the use of silicon diode detectors for clinical dosimetry in proton beams

Grusell

Medin²

2000

Phys. Med. Biol.

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The properties of silicon diode detectors, used for dosimetry in clinical proton beams, were investigated with special regard to the measurement of relative dose distributions in water. Different types of silicon diode detector were studied, and the resulting distributions of detector signal versus depth in the water phantom were compared with the corresponding distributions obtained with a plane-parallel NACP ionization chamber. The measurements were performed in a proton beam with an initial energy of 173 MeV.It is shown that the Hi-p silicon detector gives a signal which is proportional to the ionization density in the silicon crystal in all parts of the Bragg curve, and for all levels of accumulated dose to the detector. This is in contrast to detectors based on n-type silicon, or on low resistivity p-type silicon. After pre-irradiation, these latter detectors show a stopping-power dependent recombination, yielding an increase in the detector signal per unit dose with increasing LET. This effect leads to an over-response in the Bragg peak, which increases gradually with the accumulated detector dose.Using the Hi-p silicon diode detector, the depth ionization distribution was found to be equal to the distribution obtained with the plane-parallel NACP ionization chamber at all pre-irradiation levels, within the experimental accuracy. This implies that the quotient between the ionization in the detector and the absorbed dose to the surrounding water is equal for these detectors.

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Section: Introductionmentioning

confidence: 93%

General characteristics of the use of silicon diode detectors for clinical dosimetry in proton beams

Grusell

Medin²

2000

Phys. Med. Biol.

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“…While several studies characterizing diode detectors used for proton dose measurements have been published over the last four decades, these studies have often shown mixed or less-than-desirable results when compared to ionization chamber detectors. (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) However, Grusell and Medin (11) showed that a highly doped p-type Si detector designed for use with protons had a response consistent with ionization chambers, which are considered the gold standard for dose measurements. In the present study, we present results from an evaluation of the commercially available PTW PR60020 p-type diode detector specifically indicated by the manufacturer for proton dose measurements.…”

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confidence: 99%

Evaluation of the dosimetric properties of a diode detector for small field proton radiosurgery

McAuley

Teran

Slater

et al. 2015

J Applied Clin Med Phys

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The small fields and sharp gradients typically encountered in proton radiosurgery require high spatial resolution dosimetric measurements, especially below 1–2 cm diameters. Radiochromic film provides high resolution, but requires postprocessing and special handling. Promising alternatives are diode detectors with small sensitive volumes (SV) that are capable of high resolution and real‐time dose acquisition. In this study we evaluated the PTW PR60020 proton dosimetry diode using radiation fields and beam energies relevant to radiosurgery applications. Energies of 127 and 157 MeV (9.7 to 15 cm range) and initial diameters of 8, 10, 12, and 20 mm were delivered using single‐stage scattering and four modulations (0, 15, 30, and 60 mm) to a water tank in our treatment room. Depth dose and beam profile data were compared with PTW Markus N23343 ionization chamber, EBT2 Gafchromic film, and Monte Carlo simulations. Transverse dose profiles were measured using the diode in "edge‐on" orientation or EBT2 film. Diode response was linear with respect to dose, uniform with dose rate, and showed an orientation‐dependent (i.e., beam parallel to, or perpendicular to, detector axis) response of less than 1%. Diode vs. Markus depth‐dose profiles, as well as Markus relative dose ratio vs. simulated dose‐weighted average lineal energy plots, suggest that any LET‐dependent diode response is negligible from particle entrance up to the very distal portion of the SOBP for the energies tested. Finally, while not possible with the ionization chamber due to partial volume effects, accurate diode depth‐dose measurements of 8, 10, and 12 mm diameter beams were obtained compared to Monte Carlo simulations. Because of the small SV that allows measurements without partial volume effects and the capability of submillimeter resolution (in edge‐on orientation) that is crucial for small fields and high‐dose gradients (e.g., penumbra, distal edge), as well as negligible LET dependence over nearly the full the SOBP, the PTW proton diode proved to be a useful high‐resolution, real‐time metrology device for small proton field radiation measurements such as would be encountered in radiosurgery applications.PACS numbers: 87.56.‐v, 87.56.jf, 87.56.Fc

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Clinical dosimeter detectors for ionizing radiation based on semiconductor photoelectric transducers

Mandel'tsvaig¹

1968

Biomed Eng

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The use of the Miniature Silicon Diode as a Radiation Dosemeter

Abstract: The use of commercially available miniature silicon diodes as dosemeters, with particular reference t o their application to biomedical facilities a t cyclotrons, is discussed. They are simple and convenient, and their small size makes them ideal for use as beam profile detectors.

Cited by 11 publications

References 7 publications

General characteristics of the use of silicon diode detectors for clinical dosimetry in proton beams

General characteristics of the use of silicon diode detectors for clinical dosimetry in proton beams

Evaluation of the dosimetric properties of a diode detector for small field proton radiosurgery

Clinical dosimeter detectors for ionizing radiation based on semiconductor photoelectric transducers

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