The Calibration and Use of a New Ring-Shaped Ionization Chamber for Monitoring and Dosimetry of X-Ray Beams
Author(s)
Babak Sharifi1,
Hossein Zamani Zeinali2*,
Anita Alipoor2,
Arjang Shahvar1,
Ali Negarestani1
Affiliation(s)
1 Graduate University of Advanced Technology, Kerman, Iran. 2 Radiation Application Research School, Nuclear Science and Technology Research Institute, AEOI, Karaj, Iran.
1 Graduate University of Advanced Technology, Kerman, Iran. 2 Radiation Application Research School, Nuclear Science and Technology Research Institute, AEOI, Karaj, Iran.
ABSTRACT
Today, dosimeters are used generally for dosimetry of the diagnostic X-ray beam. Ionization chambers are appropriate instruments for monitoring and also the dosimetry of X-ray beam in medical diagnostic equipment. The present work introduces design and investigation of a new ring-shaped monitor chamber with a PMMA body, graphite-coated PMMA windows (0.5 mm thick), a special graphite-foil central electrode (0.1 mm thick, 0.7 g/cm3 dense) that creating two sensitive volumes and a central hole for crossing the radiation beam with less attenuation. The results of performance tests conducted at the Nuclear Science and Technology Research Institute, AEOI in Karaj- Iran proved the high short and long-term stability, the very low leakage current, the low directional dependence and very high ion collection efficiency through the special design of the collecting electrode. Moreover, the FLUKA Monte Carlo simulations certified the negligible effect of central electrode on this new ring-shaped monitor chamber. According to the results of the performance tests, the new monitor chamber can be used as a standard dosimeter in order to monitor X-ray beam in primary standard dosimetry laboratories.
Today, dosimeters are used generally for dosimetry of the diagnostic X-ray beam. Ionization chambers are appropriate instruments for monitoring and also the dosimetry of X-ray beam in medical diagnostic equipment. The present work introduces design and investigation of a new ring-shaped monitor chamber with a PMMA body, graphite-coated PMMA windows (0.5 mm thick), a special graphite-foil central electrode (0.1 mm thick, 0.7 g/cm3 dense) that creating two sensitive volumes and a central hole for crossing the radiation beam with less attenuation. The results of performance tests conducted at the Nuclear Science and Technology Research Institute, AEOI in Karaj- Iran proved the high short and long-term stability, the very low leakage current, the low directional dependence and very high ion collection efficiency through the special design of the collecting electrode. Moreover, the FLUKA Monte Carlo simulations certified the negligible effect of central electrode on this new ring-shaped monitor chamber. According to the results of the performance tests, the new monitor chamber can be used as a standard dosimeter in order to monitor X-ray beam in primary standard dosimetry laboratories.
KEYWORDS
Ring-Shaped Monitor Chamber, Diagnostic X-Ray Beam, Quality Control Tests, Low Dens Graphite-Foil, Central Electrode
Ring-Shaped Monitor Chamber, Diagnostic X-Ray Beam, Quality Control Tests, Low Dens Graphite-Foil, Central Electrode
Cite this paper
Sharifi, B. , Zeinali, H. , Alipoor, A. , Shahvar, A. and Negarestani, A. (2015) The Calibration and Use of a New Ring-Shaped Ionization Chamber for Monitoring and Dosimetry of X-Ray Beams. World Journal of Nuclear Science and Technology, 5, 200-207. doi: 10.4236/wjnst.2015.53020.
Sharifi, B. , Zeinali, H. , Alipoor, A. , Shahvar, A. and Negarestani, A. (2015) The Calibration and Use of a New Ring-Shaped Ionization Chamber for Monitoring and Dosimetry of X-Ray Beams. World Journal of Nuclear Science and Technology, 5, 200-207. doi: 10.4236/wjnst.2015.53020.
References
[1] Khan, F.M. (2010) The Physics of Radiation Therapy.4th Edition, Lippincott Williams & Wilkins, Minnesota. [2] Attix, F.H. (2008) Introduction to Radiological Physics and Radiation Dosimetry. John Wiley & Sons, Germany. [3] Perini, A.P., Neves, L.P., Fernández-Varea, J.M., Cassola, V.F., Kramer, R., Khoury, H.J. and Caldas, L.V.E. (2014) A New Parallel-Plate Graphite Ionization Chamber as a 60Co Gamma Radiation Reference Instrument. Radiation Physics and Chemistry, 95, 106-108.
http://www.sciencedirect.com/science/article/pii/s0969806x13000091
http://dx.doi.org/10.1016/j.radphyschem.2013.01.005 [4] Perini, A.P., Neves, L.P. and Caldas, L.V.E. (2014) Investigation of the Applicability of a Special Parallel-Plate Ionization Chamber for X-Ray Beam Dosimetry. Radiation Physics and Chemistry, 95, 94-97.
http://www.sciencedirect.com/science/article/pii/s0969806x13001382
http://dx.doi.org/10.1016/j.radphyschem.2013.03.006 [5] Yoshizumi, M.T., Vivolo, V. and Caldas, L.V.E. (2010) Preliminary Studies of a New Monitor Ionization Chamber. Applied Radiation and Isotopes, 68, 620-622.
http://www.sciencedirect.com/science/article/pii/s0969804309005569
http://dx.doi.org/10.1016/j.apradiso.2009.09.019 [6] IAEA (2007) Dosimetry in Diagnostic Radiology: An International Code of Practice for Dosimetry. IAEA TRS 457, Vienna. [7] IAEA (2001) Absorbed Dose Determination in External Beam Radiotherapy: An International Code of Practice for Dosimetry Based on Standards of Absorbed Dose to Water. IAEA TRS 398, Vienna. [8] IEC 60731 (2011) Medical Electrical Equipment—Dosimeters with Ionization Chambers as Used in Radiotherapy. IEC 60731, Geneva. [9] IEC 61674 (1997) Medical Electrical Equipment—Dosimeters with Ionization Chambers and/or Semi-Conductor Detectors as Used in X-Ray Diagnostic Imaging. IEC 61674, Geneva. [10] PTW Catalog (2009) Radiation Therapy in: Radiation Medicine Quality Assurance (QA) Catalog. PTW GmbH, Freiburg.
[1] Khan, F.M. (2010) The Physics of Radiation Therapy.4th Edition, Lippincott Williams & Wilkins, Minnesota. [2] Attix, F.H. (2008) Introduction to Radiological Physics and Radiation Dosimetry. John Wiley & Sons, Germany. [3] Perini, A.P., Neves, L.P., Fernández-Varea, J.M., Cassola, V.F., Kramer, R., Khoury, H.J. and Caldas, L.V.E. (2014) A New Parallel-Plate Graphite Ionization Chamber as a 60Co Gamma Radiation Reference Instrument. Radiation Physics and Chemistry, 95, 106-108.
http://www.sciencedirect.com/science/article/pii/s0969806x13000091
http://dx.doi.org/10.1016/j.radphyschem.2013.01.005 [4] Perini, A.P., Neves, L.P. and Caldas, L.V.E. (2014) Investigation of the Applicability of a Special Parallel-Plate Ionization Chamber for X-Ray Beam Dosimetry. Radiation Physics and Chemistry, 95, 94-97.
http://www.sciencedirect.com/science/article/pii/s0969806x13001382
http://dx.doi.org/10.1016/j.radphyschem.2013.03.006 [5] Yoshizumi, M.T., Vivolo, V. and Caldas, L.V.E. (2010) Preliminary Studies of a New Monitor Ionization Chamber. Applied Radiation and Isotopes, 68, 620-622.
http://www.sciencedirect.com/science/article/pii/s0969804309005569
http://dx.doi.org/10.1016/j.apradiso.2009.09.019 [6] IAEA (2007) Dosimetry in Diagnostic Radiology: An International Code of Practice for Dosimetry. IAEA TRS 457, Vienna. [7] IAEA (2001) Absorbed Dose Determination in External Beam Radiotherapy: An International Code of Practice for Dosimetry Based on Standards of Absorbed Dose to Water. IAEA TRS 398, Vienna. [8] IEC 60731 (2011) Medical Electrical Equipment—Dosimeters with Ionization Chambers as Used in Radiotherapy. IEC 60731, Geneva. [9] IEC 61674 (1997) Medical Electrical Equipment—Dosimeters with Ionization Chambers and/or Semi-Conductor Detectors as Used in X-Ray Diagnostic Imaging. IEC 61674, Geneva. [10] PTW Catalog (2009) Radiation Therapy in: Radiation Medicine Quality Assurance (QA) Catalog. PTW GmbH, Freiburg.