WorldWideScience

Sample records for accredited dosimetry calibration

  1. QA experience at the University of Wisconsin accredited dosimetry calibration laboratory

    The University of Wisconsin Accredited Dosimetry Calibration Laboratory (UW ADCL) employs procedure manuals as part of its Quality Assurance (QA) program. One of these manuals covers the QA procedures and results for all of the UW ADCL measurement equipment. The QA procedures are divided into two main areas: QA for laboratory equipment and QA for external chambers sent for calibration. All internal laboratory equipment is checked and recalibrated on an annual basis, after establishing its consistency on a 6-month basis. QA for external instruments involves checking past calibration history as well as comparing to a range of calibration values for specific instrument models. Generally, the authors find that a chamber will have a variation of less than 0.5 % from previous Co-60 calibration factors, and falls within two standard deviations of previous calibrations. If x-ray calibrations are also performed, the energy response of the chamber is plotted and compared to previous instruments of the same model. These procedures give the authors confidence in the transfer of calibration values from National Institute of Standards and Technology (NIST)

  2. QA experience at the University of Wisconsin accredited dosimetry calibration laboratory

    DeWard, L.A.; Micka, J.A. [Univ. of Wisconsin, Madison, WI (United States)

    1993-12-31

    The University of Wisconsin Accredited Dosimetry Calibration Laboratory (UW ADCL) employs procedure manuals as part of its Quality Assurance (QA) program. One of these manuals covers the QA procedures and results for all of the UW ADCL measurement equipment. The QA procedures are divided into two main areas: QA for laboratory equipment and QA for external chambers sent for calibration. All internal laboratory equipment is checked and recalibrated on an annual basis, after establishing its consistency on a 6-month basis. QA for external instruments involves checking past calibration history as well as comparing to a range of calibration values for specific instrument models. Generally, the authors find that a chamber will have a variation of less than 0.5 % from previous Co-60 calibration factors, and falls within two standard deviations of previous calibrations. If x-ray calibrations are also performed, the energy response of the chamber is plotted and compared to previous instruments of the same model. These procedures give the authors confidence in the transfer of calibration values from National Institute of Standards and Technology (NIST).

  3. History, organization, and oversight of the accredited dosimetry calibration laboratories by the AAPM

    For more than 20 years, the American Association of Physicists in Medicine (AAPM) has operated an accreditation program for secondary standards laboratories that calibrate radiation measuring instruments. Except for one short period, that program has been able to provide the facilities to satisfy the national need for accurate calibrations of such instruments. That exception, in 1981, due to the combination of the U.S. Nuclear Regulatory Commission (NRC) requiring instrument calibrations by users of cobalt-60 teletherapy units and the withdrawal of one of the three laboratories accredited at that time. However, after successful operation as a Task Group of the Radiation Therapy Committee (RTC) of the AAPM for two decades, a reorganization of this structure is now under serious consideration by the administration of the AAPM

  4. History, organization, and oversight of the accredited dosimetry calibration laboratories by the AAPM

    Rozenfeld, M. [St. James Hospital and Health Centers, Chicago Heights, IL (United States)

    1993-12-31

    For more than 20 years, the American Association of Physicists in Medicine (AAPM) has operated an accreditation program for secondary standards laboratories that calibrate radiation measuring instruments. Except for one short period, that program has been able to provide the facilities to satisfy the national need for accurate calibrations of such instruments. That exception, in 1981, due to the combination of the U.S. Nuclear Regulatory Commission (NRC) requiring instrument calibrations by users of cobalt-60 teletherapy units and the withdrawal of one of the three laboratories accredited at that time. However, after successful operation as a Task Group of the Radiation Therapy Committee (RTC) of the AAPM for two decades, a reorganization of this structure is now under serious consideration by the administration of the AAPM.

  5. Radiation protection dosimetry and calibrations

    At the SCK-CEN different specialised services are delivered for a whole range of external and internal customers in the radiation protection area. For the expertise group of radiation protection dosimetry and calibrations, these services are organized in four different laboratories: dosimetry, anthropogammametry, nuclear calibrations and non-nuclear calibrations. The services are given by a dedicated technical staff who has experience in the handling of routine and specialised cases. The scientific research that is performed by the expertise group makes sure that state-of-the-art techniques are being used, and that constant improvements and developments are implemented. Quality Assurance is an important aspect for the different services, and accreditation according national and international standards is achieved for all laboratories

  6. US accreditation programmes for personal radiation dosimetry

    In order to verify an acceptable level of safety in the workplace, it is necessary to measure the quantity of ionising radiation to which radiation workers could be, or actually are, exposed. At present, there are organisations capable of providing measurement results with good accuracy and precision. These organisations may provide personal dosimetry services to their own facilities, or to others on a contractual basis. They generally have high quality equipment and well trained personnel. However, in today's climate, it is important to demonstrate and document that these systems and services to others meet national standards of quality. In order to provide a higher level of confidence in the results generated by organisations that provide personal dosimetry services in the US, two accreditation programmes have been established. They are the Department of Energy Laboratory Accreditation Program (DOELAP) and the National Voluntary Laboratory Accreditation Program (NVLAP). These two programmes will be described and results will be given, along with plans for future development. (author)

  7. Dosimetry and Calibration Section

    The Dosimetry and Calibration Section fulfils two tasks within CERN's Radiation Protection Group: the Individual Dosimetry Service monitors more than 5000 persons potentially exposed to ionizing radiation on the CERN sites, and the Calibration Laboratory verifies throughout the year, at regular intervals, over 1000 instruments, monitors, and electronic dosimeters used by RP Group. The establishment of a Quality Assurance System for the Individual Dosimetry Service, a requirement of the new Swiss Ordinance for personal dosimetry, put a considerable workload on the section. Together with an external consultant it was decided to identify and then describe the different 'processes' of the routine work performed in the dosimetry service. The resulting Quality Manual was submitted to the Federal Office for Public Health in Bern in autumn. The CERN Individual Dosimetry Service will eventually be officially endorsed after a successful technical test in March 1999. On the technical side, the introduction of an automatic development machine for gamma films was very successful. It processes the dosimetric films without an operator being present, and its built-in regeneration mechanism keeps the concentration of the processing chemicals at a constant level

  8. Dosimetry and Calibration Section

    The two tasks of the Dosimetry and Calibration Section at CERN are the Individual Dosimetry Service which assures the personal monitoring of about 5000 persons potentially exposed to ionizing radiation at CERN, and the Calibration Laboratory which verifies all the instruments and monitors. This equipment is used by the sections of the RP Group for assuring radiation protection around CERN's accelerators, and by the Environmental Section of TISTE. In addition, nearly 250 electronic and 300 quartz fibre dosimeters, employed in operational dosimetry, are calibrated at least once a year. The Individual Dosimetry Service uses an extended database (INDOS) which contains information about all the individual doses ever received at CERN. For most of 1997 it was operated without the support of a database administrator as the technician who had assured this work retired. The Software Support Section of TIS-TE took over the technical responsibility of the database, but in view of the many other tasks of this Section and the lack of personnel, only a few interventions for solving immediate problems were possible

  9. Individual dosimetry and calibration

    In 1995 both the Individual Dosimetry and Calibration Sections worked under the condition of a status quo and concentrated fully on the routine part of their work. Nevertheless, the machine for printing the bar code which will be glued onto the film holder and hence identify the people when entering into high radiation areas was put into operation and most of the holders were equipped with the new identification. As far as the Calibration Section is concerned the project of the new source control system that is realized by the Technical Support Section was somewhat accelerated

  10. HPS instrument calibration laboratory accreditation program

    The purpose of this paper is to provide an accurate overview of the development and structure of the program established by the Health Physics Society (HPS) for accrediting instrument calibration laboratories relative to their ability to accurately calibrate portable health physics instrumentation. The purpose of the program is to provide radiation protection professionals more meaningful direct and indirect access to the National Institute of Standards and Technology (NIST) national standards, thus introducing a means for improving the uniformity, accuracy, and quality of ionizing radiation field measurements. The process is designed to recognize and document the continuing capability of each accredited laboratory to accurately perform instrument calibration. There is no intent to monitor the laboratory to the extent that each calibration can be guaranteed by the program; this responsibility rests solely with the accredited laboratory

  11. HPS instrument calibration laboratory accreditation program

    Masse, F.X; Eisenhower, E.H.; Swinth, K.L.

    1993-12-31

    The purpose of this paper is to provide an accurate overview of the development and structure of the program established by the Health Physics Society (HPS) for accrediting instrument calibration laboratories relative to their ability to accurately calibrate portable health physics instrumentation. The purpose of the program is to provide radiation protection professionals more meaningful direct and indirect access to the National Institute of Standards and Technology (NIST) national standards, thus introducing a means for improving the uniformity, accuracy, and quality of ionizing radiation field measurements. The process is designed to recognize and document the continuing capability of each accredited laboratory to accurately perform instrument calibration. There is no intent to monitor the laboratory to the extent that each calibration can be guaranteed by the program; this responsibility rests solely with the accredited laboratory.

  12. Accreditation ISO/IEC 1705 in dosimetry: Experience and results

    The objective of this work is to present the experience in the process of accreditation of the radiation dosimetry service in which there are trials for the determination of radiation doses due to internal and external exhibitions. Is They describe the aspects that were considered for the design and development of a system of quality and results after its implementation. A review of the benefits accreditation has been reported to the organization is finally made. (Author)

  13. The method validation step of biological dosimetry accreditation process

    One of the missions of the Laboratory of Biological Dosimetry (L.D.B.) of the Institute for Radiation and Nuclear Safety (I.R.S.N.) is to assess the radiological dose after an accidental overexposure suspicion to ionising radiation, by using radio-induced changes of some biological parameters. The 'gold standard' is the yield of dicentrics observed in patients lymphocytes, and this yield is converted in dose using dose effect relationships. This method is complementary to clinical and physical dosimetry, for medical team in charge of the patients. To obtain a formal recognition of its operational activity, the laboratory decided three years ago, to require an accreditation, by following the recommendations of both 17025 General Requirements for the Competence of Testing and Calibration Laboratories and 19238 Performance criteria for service laboratories performing biological dosimetry by cyto-genetics. Diagnostics, risks analysis were realized to control the whole analysis process leading to documents writing. Purchases, personnel department, vocational training were also included in the quality system. Audits were very helpful to improve the quality system. One specificity of this technique is that it is not normalized therefore apart from quality management aspects, several technical points needed some validations. An inventory of potentially influent factors was carried out. To estimate their real effect on the yield of dicentrics, a Placket-Burman experimental design was conducted. The effect of seven parameters was tested: the BUdr (bromodeoxyuridine), PHA (phytohemagglutinin) and colcemid concentration, the culture duration, the incubator temperature, the blood volume and the medium volume. The chosen values were calculated according to the uncertainties on the way they were measured i.e. pipettes, thermometers, test tubes. None of the factors has a significant impact on the yield of dicentrics. Therefore the uncertainty linked to their use was considered as

  14. Accreditation of the Personal Dosimetry internal Service Tecnatom by the National Entity (ENAC)

    The service of personal Dosimetry internal Tecnatom has made the process of adapting its methodology and quality assurance, requirements technical and management will be required to obtain accreditation from the National Accreditation Entity according to ISO / IEC 170251 standard General Requirements competence of testing and calibration laboratories. To carry out this process, the laboratory has defined quality criteria set out in their test procedures, based on ISO Standards 27048: 2011; ISO 20553: 2005 and ISO 28218: 2010. This paper describes what has been the methodology used to implement the requirements of different ISO test methods of SDPI Tecnatom. (Author)

  15. Requirements for the accreditation of a calibration laboratory

    CNEA's activity in calibration is recent but it has a significant development. To assure high quality results, activity must be sustained and improved from day to day. The calibrations laboratory was accredited before Laboratories Qualification Committee, thus adding reliability to its results and making it more competitive when compared to other laboratories not accredited. Among other services given are supervision and follow up of calibrations in laboratories, participation in interlaboratory assays together with other calibration laboratories and assessments on calibration aspects of measuring equipment. (author)

  16. US Department of Energy Laboratory Accredition Program (DOELAP) for personnel dosimetry systems

    Cummings, F.M.; Carlson, R.D.; Loesch, R.M.

    1993-12-31

    Accreditation of personnel dosimetry systems is required for laboratories that conduct personnel dosimetry for the U.S. Department of Energy (DOE). Accreditation is a two-step process which requires the participant to pass a proficiency test and an onsite assessment. The DOE Laboratory Accreditation Program (DOELAP) is a measurement quality assurance program for DOE laboratories. Currently, the DOELAP addresses only dosimetry systems used to assess the whole body dose to personnel. A pilot extremity DOELAP has been completed and routine testing is expected to begin in January 1994. It is expected that participation in the extremity program will be a regulatory requirement by January 1996.

  17. The Belgian laboratory for standard dosimetry calibrations used in radiotherapy

    Starting from the end of the year 2008, the RDC (Radiation Protection dosimetry and Calibrations) expertise group of SCK CEN took over the calibration and research activities at the Laboratory for Standard Dosimetry Ghent. The laboratory runs under a collaboration between SCK CEN and the University of Ghent, with the support of Federal Agency for Nuclear Control (FANC). The calibrations in Ghent were stopped at the beginning of 2008 and then restarted at the end of 2008. A new 60Co source was installed at Ghent, a Theratron 780 unit. All the calibration setups installed in the past to the old 60Co source had to move to the new source and measurement history had to be acquired. The calibration of cylindrical and plane-parallel ionization chambers in terms of absorbed dose to water was defined as the first priority, since there was an urgent need from the Belgian hospitals. These calibrations are presently done in Ghent as secondary standard calibrations, traceable to the water calorimeter of VSL, Delft, The Netherlands and following the recommendations from TRS-398 protocol. The second priority was restarting the calibrations of cylindrical ionization chambers in terms of air kerma. A cylindrical graphite ionization chamber of type CC01 is used for the absolute measurement of air kerma. Both setups are fully operational. Special efforts were done to implement the SCK CEN quality assurance (QA) system regarding ISO 17025 accreditation. The activity at the laboratory in Ghent was integrated as part of the Laboratory for Nuclear Calibrations (LNK-from the Dutch translation) of the SCK-CEN. Most of the activities of the LNK are already accredited by Belgian Accreditation Body (BELAC) with respect to the ISO-17025 standards. The quality assurance procedures were prepared and are routinely followed for the two new setups mentioned above: calibrations in terms of absorbed dose to water and air kerma in 60Co beam. During the preparation of the quality assurance procedures

  18. High-dose secondary calibration laboratory accreditation program

    There is a need for high-dose secondary calibration laboratories to serve the multi-billion dollar radiation processing industry. This need is driven by the desires of industry for less costly calibrations and faster calibration-cycle response time. Services needed include calibration irradiations of routine processing dosimeters and the supply of reference standard transfer dosimeters for irradiation in the production processing facility. In order to provide measurement quality assurance and to demonstrate consistency with national standards, the high-dose secondary laboratories would be accredited by means of an expansion of an existing National Voluntary Laboratory Accreditation Program. A laboratory performance criteria document is under development to implement the new program

  19. High-dose secondary calibration laboratory accreditation program

    Humphreys, J.C. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

    1993-12-31

    There is a need for high-dose secondary calibration laboratories to serve the multi-billion dollar radiation processing industry. This need is driven by the desires of industry for less costly calibrations and faster calibration-cycle response time. Services needed include calibration irradiations of routine processing dosimeters and the supply of reference standard transfer dosimeters for irradiation in the production processing facility. In order to provide measurement quality assurance and to demonstrate consistency with national standards, the high-dose secondary laboratories would be accredited by means of an expansion of an existing National Voluntary Laboratory Accreditation Program. A laboratory performance criteria document is under development to implement the new program.

  20. Calibration methods of plane-parallel ionization chambers used in electron dosimetry

    The use of linear accelerators in radiotherapy is of great importance in Medicine, and according to international recommendations the electron beam dosimetry has to be performed using plane-parallel ionization chambers, previously calibrated in standard gamma radiation fields at accredited laboratories. In this work, calibration methods of plane-parallel ionization chambers used in dosimetry procedures of high energy electron beams of clinical accelerators were presented, tested and intercompared. The experiments were carried out using gamma radiation beams of 60 Co at the Calibration Laboratory of Clinical Dosemeters at IPEN and electron beams od 4 to 16 MeV at the Radiotherapy Department of Hospital Israelita Albert Einstein, Sao Paulo. A method was chosen to be established at IPEN. Proposals of the calibration procedure, calibration certificate and data sheets are presented. (author)

  1. Implementation of ISO guide 25 in a medical dosimetry secondary standards calibration laboratory

    Currently, there is a great deal of discussion among industry and government agencies about ISO 9000 accreditation. U.S. manufacturers with ISO 9000 accreditation are regarded more favorably by European countries. The principles behind the ISO 9000 accreditation are based on the Total Quality Management (TQM) principles that are being implemented in many U.S. industries. This paper will deal only with the calibration issue. There is a difference in the areas covered by ISO 9000 and ISO Guide 25 documents. ISO 9000, in particular ISO 9001 - ISO 9003, cover the open-quotes calibrationclose quotes of inspection, measuring and test equipment. This equipment is basically used for open-quotes factory calibrationsclose quotes to determine that equipment is performing within manufacturer specifications. ISO Guide 25 is specifically for open-quotes calibration and testing laboratories,close quotes generally laboratories that have painstaking procedures to reduce uncertainties and establish high accuracy of the transfer of calibration. The experience of the University of Wisconsin Accredited Dosimetry Calibration Laboratory in conforming to ISO Guide 25 will be outlined. The entire laboratory staff must become familiar with the process and an individual with direct authority must become the one to maintain the quality of equipment and calibrations in the role of open-quotes quality-assurance manager.close quotes

  2. Calibration facility for environment dosimetry instruments

    Bercea, Sorin; Celarel, Aurelia; Cenusa, Constantin [Horia Hulubei National Institute for Physics and Nuclear Engineering, 30 Reactorului St, Magurele, Jud Ilfov, P.O.B. MG-6, RO-077125 (Romania)

    2013-12-16

    In the last ten years, the nuclear activities, as well as the major nuclear events (see Fukushima accident) had an increasing impact on the environment, merely by contamination with radioactive materials. The most conferment way to quickly identify the presence of some radioactive elements in the environment, is to measure the dose-equivalent rate H. In this situation, information concerning the values of H due only to the natural radiation background must exist. Usually, the values of H due to the natural radiation background, are very low (∼10{sup −9} - 10{sup −8} Sv/h). A correct measurement of H in this range involve a performing calibration of the measuring instruments in the measuring range corresponding to the natural radiation background lead to important problems due to the presence of the natural background itself the best way to overlap this difficulty is to set up the calibration stand in an area with very low natural radiation background. In Romania, we identified an area with such special conditions at 200 m dept, in a salt mine. This paper deals with the necessary requirements for such a calibration facility, as well as with the calibration stand itself. The paper includes also, a description of the calibration stand (and images) as well as the radiological and metrological parameters. This calibration facilities for environment dosimetry is one of the few laboratories in this field in Europe.

  3. Calibration facility for environment dosimetry instruments

    In the last ten years, the nuclear activities, as well as the major nuclear events (see Fukushima accident) had an increasing impact on the environment, merely by contamination with radioactive materials. The most conferment way to quickly identify the presence of some radioactive elements in the environment, is to measure the dose-equivalent rate H. In this situation, information concerning the values of H due only to the natural radiation background must exist. Usually, the values of H due to the natural radiation background, are very low (∼10−9 - 10−8 Sv/h). A correct measurement of H in this range involve a performing calibration of the measuring instruments in the measuring range corresponding to the natural radiation background lead to important problems due to the presence of the natural background itself the best way to overlap this difficulty is to set up the calibration stand in an area with very low natural radiation background. In Romania, we identified an area with such special conditions at 200 m dept, in a salt mine. This paper deals with the necessary requirements for such a calibration facility, as well as with the calibration stand itself. The paper includes also, a description of the calibration stand (and images) as well as the radiological and metrological parameters. This calibration facilities for environment dosimetry is one of the few laboratories in this field in Europe

  4. Proposal of a Brazilian accreditation program for personal dosimetry using OSL

    After the development of the highly sensitive material Al2O3:C, personal dosimetry using optically stimulated luminescence (OSL) has been continuously adopted in place of thermoluminescence dosimeters (TLD) by different countries (e.g. USA and Japan). In order to use a dosimetric system in Brazil it is necessary to develop a protocol and to fulfill performance and type tests in accordance with the accreditation program approved by the responsible governmental committee. This paper presents a proposal for an accreditation program for OSL personal dosimetry using a commercial dosimetric system, including tests that follow the same rules as applied to TLD and film dosimetry. The experimental results are within the reliability interval and in accordance to the expected behavior. A new test concerning re-analysis of exposed badges is also proposed.

  5. Accreditation of a personal dosimetry service in Switzerland: Practical experience and transition from EN 45004 to ISO 17025

    In compliance with the Swiss legislation on radiological protection, the Paul Scherrer Institute (PSI) operates a dosimetry service that is approved by the Swiss Federal Nuclear Safety Inspectorate. In 1997, the dosimetry service was also accredited by the Swiss Federal Office of Metrology and Accreditation as an inspection body for legal personal and environmental dosimetry, according to EN 45004. The accreditation covers determination of personal dose equivalent for photon, neutron and beta radiation, and ambient dose equivalent for photon and neutron radiation, by means of thermoluminescence and solid state track detection techniques. Within this formal accreditation it was confirmed that the relevant requirements of ISO 9002 are also fulfilled. The first re-accreditation will take place in 2001 and work is going on to achieve the transition from EN 45004 to ISO 17025. Accreditation is a feasible, practicable and acceptable way to achieve harmonisation in the field of dosimetry. However, before starting on the path to formal accreditation, a careful analysis should be made, taking into consideration not only cost-benefit aspects but also national legal requirements. (author)

  6. Dose calibration optimization and error propagation in polymer gel dosimetry

    This study reports on the relative precision, relative error, and dose differences observed when using a new full-image calibration technique in NIPAM-based x-ray CT polymer gel dosimetry. The effects of calibration parameters (e.g. gradient thresholding, dose bin size, calibration fit function, and spatial remeshing) on subsequent errors in calibrated gel images are reported. It is found that gradient thresholding, dose bin size, and fit function all play a primary role in affecting errors in calibrated images. Spatial remeshing induces minimal reductions or increases in errors in calibrated images. This study also reports on a full error propagation throughout the CT gel image pre-processing and calibration procedure thus giving, for the first time, a realistic view of the errors incurred in calibrated CT polymer gel dosimetry. While the work is based on CT polymer gel dosimetry, the formalism is valid for and easily extended to MRI or optical CT dosimetry protocols. Hence, the procedures developed within the work are generally applicable to calibration of polymer gel dosimeters. (paper)

  7. Dosimetry intercomparisons in European medical device sterilization plants

    Miller, A.; Sharpe, P.H.G.

    2000-01-01

    Dosimetry intercomparisons have been carried out involving two-thirds of all European radiation sterilization facilities. Dosimeters for the intercomparisons were supplied by two accredited calibration laboratories. The results show good agreement, and indicate overall dosimetry accuracy of the o......Dosimetry intercomparisons have been carried out involving two-thirds of all European radiation sterilization facilities. Dosimeters for the intercomparisons were supplied by two accredited calibration laboratories. The results show good agreement, and indicate overall dosimetry accuracy...

  8. Accreditation ISO/IEC 1705 in dosimetry: Experience and results; Acreditacion ISO/IEC 17025 en dosimetria: Experiencia y resultados

    Martin Garcia, R.; Navarro Bravo, T.

    2013-07-01

    The objective of this work is to present the experience in the process of accreditation of the radiation dosimetry service in which there are trials for the determination of radiation doses due to internal and external exhibitions. Is They describe the aspects that were considered for the design and development of a system of quality and results after its implementation. A review of the benefits accreditation has been reported to the organization is finally made. (Author)

  9. Secondary calibration laboratory for ionizing radiation laboratory accreitation program National Institute of Standards and Technology National Voluntary Laboratory Accreditation Program

    Martin, P.R.

    1993-12-31

    This paper presents an overview of the procedures and requirements for accreditation under the Secondary Calibration Laboratory for Ionizing Radiation Program (SCLIR LAP). The requirements for a quality system, proficiency testing and the onsite assessment are discussed. The purpose of the accreditation program is to establish a network of secondary calibration laboratories that can provide calibrations traceable to the primary national standards.

  10. Establishment of qualities mammography according to the standard IEC-61267 in the laboratory of metrology of ionizing radiation of the National Center of Dosimetry and enlargement of the accreditation by ENAC; Establecimiento de las calidades de mamografia segun la norma IEC-61267 en el laboratorio de metrologia de radiaciones ionizantes del centro nacional de dosimetria (CND) y proceso de ampliacion de su acreditacion por ENAC

    Roig Petit, F.; Mestre de Juan, V.; Alabau Albors, J.; Palma Copete, J.; Ruiz Rodriguez, J. C.; Pons Mocholi, S.

    2013-07-01

    The extension of the accreditation of the laboratory of the National Center Dosimetry (No. 58/LC10.036) by the national accreditation entity (ENAC), according to the ISO 17025 standard [2], for the standard qualities of mammography by the IEC 61267 comes to meet part of the needs that demand our health care environment in terms of radiation measuring instruments calibration. This work intends to publicize this enlargement commenting on the different phases of the process to get the accreditation. (Author)

  11. Accreditation of the Personal Dosimetry internal Service Tecnatom by the National Entity (ENAC); Acreditacion del Servicio de Dosimetria Personal Interna de Tecnatom por la Entidad Nacional de Acreditacion (ENAC)

    Bravo, B.; Marchena, P.

    2014-07-01

    The service of personal Dosimetry internal Tecnatom has made the process of adapting its methodology and quality assurance, requirements technical and management will be required to obtain accreditation from the National Accreditation Entity according to ISO / IEC 170251 standard {sup G}eneral Requirements competence of testing and calibration laboratories. To carry out this process, the laboratory has defined quality criteria set out in their test procedures, based on ISO Standards 27048: 2011; ISO 20553: 2005 and ISO 28218: 2010. This paper describes what has been the methodology used to implement the requirements of different ISO test methods of SDPI Tecnatom. (Author)

  12. Quality assurance manual for the Department of Energy laboratory accreditation program for personnel dosimetry systems

    The overall purpose of this document is to establish a uniform approach to quality assurance. This will ensure that uniform, high-quality personnel dosimetry practices are followed by the participating testing laboratories. The document presents guidelines for calibrating and maintaining measurement and test equipment (M and TE), calibrating radiation fields, and subsequently irradiating and handling personnel dosimeters in laboratories involved in the DOE dosimetry systems testing program. Radiation energies for which the test procedures apply are photons with approximately 15 keV to 2 MeV, beta particles above 0.3 MeV, neutrons with approximately 1 keV to 2 MeV. 12 refs., 4 tabs

  13. Reliability, calibration and metrology in ionizing radiation dosimetry

    Cundin, Luisiana X

    2013-01-01

    Radiation dosimetry systems are complex systems, comprised of a milieu of components, designed for determining absorbed dose after exposure to ionizing radiation. Although many materials serve as absorbing media for measurement, thermoluminescent dosimeters represent some of the more desirable materials available; yet, reliability studies have revealed a clear and definite decrement in dosimeter sensitivity after repeated use. Unfortunately, repeated use of any such material for absorbing media in ionizing radiation dosimetry will in time experience performance decrements; thus, in order to achieve the most accuracy and/or precision in dosimetry, it is imperative proper compensation be made in calibration. Yet, analysis proves the majority of the measured decrement in sensitivity experienced by dosimeters is attributable to drift noise and not to any degradation in dosimeter performance, at least, not to any great degree. In addition to investigating dosimeter reliability, implications for metrological tracea...

  14. Accreditation of a system of extremity dosimetry: validation and uncertainty of method; Acreditacion de un sistema de dosimetria de extremidades: validacion e incertidumbre del metodo

    Romero Gutierrez, A. M.; Rodriguez Jimenez, R.; Lopez Moyano, J. L.

    2013-07-01

    The authors' goal is to spread the practical experience gained during the accreditation process paying special attention to the process of method validation and estimation uncertainty of the dosimetry system. (Author)

  15. Calibration methods of plane-parallel ionization chambers used in electron dosimetry; Metodos de calibracao de camaras de ionizacao de placas paralelas para dosimetria de feixes de eletrons

    Bulla, Roseli Tadeu

    1999-07-01

    The use of linear accelerators in radiotherapy is of great importance in Medicine, and according to international recommendations the electron beam dosimetry has to be performed using plane-parallel ionization chambers, previously calibrated in standard gamma radiation fields at accredited laboratories. In this work, calibration methods of plane-parallel ionization chambers used in dosimetry procedures of high energy electron beams of clinical accelerators were presented, tested and intercompared. The experiments were carried out using gamma radiation beams of {sup 60} Co at the Calibration Laboratory of Clinical Dosemeters at IPEN and electron beams od 4 to 16 MeV at the Radiotherapy Department of Hospital Israelita Albert Einstein, Sao Paulo. A method was chosen to be established at IPEN. Proposals of the calibration procedure, calibration certificate and data sheets are presented. (author)

  16. Dosimetry through the Secondary Laboratory of Dosimetric Calibration of Mexico

    In the beginnings of the sixty years an urgent necessity is presented mainly in the developing countries, of improving in important form the accuracy in the dosimetry of external faces in therapy of radiations (radiotherapy centers), mainly in the calibration of clinical dosemeters. In 1976 the International Atomic Energy Agency, (IAEA), and the World Health Organization, (WHO), they carried out a mutual agreement with regard to the establishment and operation of a net of Secondary Patron Laboratories of Dosimetry, (LSCD). The necessity to establish measure patterns in the field of the dosimetry of the ionizing radiations, is necessary, to have an accuracy but high in the dosimetry of the radiation beams in therapy which is highly dependent of the dose given to the tumor of those patient with cancer. Similar levels of accuracy are required in protection measures to the radiation with an acceptable smaller accuracy, however, when the personal dosemeters are used to determine the doses received by the individuals under work conditions, such mensurations in therapy of radiations and radiological protection will have traceability through a chain of comparisons to primary or national patterns. The traceability is necessary to assure the accuracy and acceptability of the dosimetric measures, as well as, the legal and economic implications. The traceability is also necessary in the dosimetry of high dose like in the sterilization of different products. The main function of the LSCD is to provide a service in metrology of ionizing radiations, maintaining the secondary or national patterns, which have a traceability to the International System of measures, which is based for if same in the comparison of patterns in the Primary Laboratories of Dosimetry (LPD) under the auspice of the International Office of Weights and Measure (BIPM). The secondary and national patterns in the LSCD constitute in Mexico, the national patterns of the magnitudes in the dosimetry of the ionizing

  17. Panoptes: Calibration of a dosimetry system for eye brachytherapy

    Intraocular cancer is a serious threat to the lives of those that suffer from it. Dosimetry for eye brachytherapy presents a significant challenge due to the inherently steep dose gradients that are needed to treat such small tumours in close proximity to sensitive normal structures. This issue is addressed by providing much needed quality assurance to eye brachytherapy, a novel volumetric dosimetry system, called PANOPTES was developed. This study focuses on the preliminary characterisation and calibration of the system. Using ion beam facilities, the custom, pixelated silicon detector of PANOPTES was shown to have good charge collection uniformity and a well defined sensitive volume. Flat-field calibration was conducted on the device using a 250 kVp orthovoltage beam. Finally, the detector and phantom were simulated with Monte Carlo in Geant4, to create water equivalent dose correction factors for each pixel across a range of angles. - Highlights: • Volumetric detector system produced for plaque brachytherapy. • Orthovoltage, flat-field calibration performed for detector pixels. • Monte Carlo simulation showed mostly little angular deviation across all angles. • Ion beam induced charge collection showed pixels uniform and fully depleted

  18. The U.S. Department of Energy Laboratory Accreditation Program for testing the performance of extremity dosimetry systems: a summary of the program status

    In 1986, The U.S. Department of Energy (DOE) implemented a program to test the performance of its personnel whole-body dosimetry systems. This program was the DOE Laboratory Accreditation Program (DOELAP). The program parallels the performance testing program specified in the American National Standard for Dosimetry - Personnel Dosimetry Performance -Criteria for Testing (ANSI N13.11-1983), but also addresses the additional dosimetry needs of DOE facilities. As an extension of the whole-body performance testing program, the DOE is now developing a program to test the performance of personnel extremity dosimetry systems. The draft DOE standard for testing extremity dosimetry systems is much less complex than the whole-body dosimetry standard and reflects the limitations imposed on extremity dosimetry by dosimeter design and irradiation geometry. A pilot performance test session has been conducted to evaluate the proposed performance-testing standard. (author)

  19. Anniversary Paper: Fifty years of AAPM involvement in radiation dosimetry

    This article reviews the involvement of the AAPM in various aspects of radiation dosimetry over its 50 year history, emphasizing the especially important role that external beam dosimetry played in the early formation of the organization. Topics covered include the AAPM's involvement with external beam and x-ray dosimetry protocols, brachytherapy dosimetry, primary standards laboratories, accredited dosimetry chains, and audits for machine calibrations through the Radiological Physics Center

  20. Some methods for calibration and beta radiation dosimetry

    The calibration of beta radiation was studied from the point of view of primary and secondary standardization, using extrapolation chambers and examining several effects. The properties of a commercial ionization chamber were investigated, and the possibility of its use in calibration and dosimetry of 90Sr- 90Y beta radiation was demonstrated . A secondary standard calibration facility was developed and the results obtained with this facility were compared with those obtained from a primary system directly or indirectly. Nearly energy independent response was obtained in.the range 60 keV to 0,8 MeV with this secondary standard. Two solid state techniques namely thermoluminescence (TL) and thermally stimulated exoelectron emission (TSEE) were also used for beta dosimetry. Various characteristics like reproducibility, response with dose,energy dependence, etc. were studied for the materials: LiF, CaF2,Li2B4O7, Be O, CaSO4 and Al2O3. TL detectors of thickness 0,9 mm underestimate the dose 60 μm thick CaSO4:Tm embedded on a thin aluminium plate gave energy independent response behind skin layers of 7 mg/cm2. Mixed field of beta, X and gamma radiation was analysed using this detector. Quartz based Be O and graphite based alpha beta-Al2O3 were found to be good beta radiation detectors when the TSEE technique is used. Energy independent CaSO4:Tm TL dosimeters were used in international comparison for dose measurements and the results obtained were in agreement with the actual given doses within 10%. The TL detectors were also used for dose rate measurements from glazed painted tiles used in construction industry and a 85Kr source used in textile and metal industries. Results obtained in the later case were Q compared with those using the secondary standard facility. (author)

  1. High-dose dosimetry at ANSTO: quality assurance, calibration and traceability

    A overview of the techniques used by ANSTO's high-dose dosimetry laboratory is given, commencing with a description of the facilities operated and the nature of the services provided. The dosimetry systems used by ANSTO are detailed along with their applications. Techniques used for calibration of dosimeters and radiation sources are given, including traceability and measurement uncertainty considerations. Quality assurance aspects of the dosimetry service are discussed. (author)

  2. Dose calibration of EPIDs for segmented IMRT dosimetry.

    Deshpande, Shrikant; Xing, Aitang; Holloway, Lois; Metcalfe, Peter; Vial, Philip

    2014-01-01

    The purpose of this study was to investigate the dose response of amorphous silicon (a-Si) electronic portal imaging devices (EPIDs) under different acquisi- tion settings for both open jaw defined fields and segmented intensity-modulated radiation therapy (IMRT) fields. Four different EPIDs were used. Two Siemens and one Elekta plus a standalone Perkin Elmer research EPID. Each was operated with different acquisition systems and settings. Dose response linearity was measured for open static jaw defined fields and 'simple' segmented IMRT fields for a range of equipment and system settings. Six 'simple' segmented IMRT fields were used. The segments of each IMRT field were fixed at 10 × 10 cm2 field size with equal MU per segment, each field having a total of 20 MU. Simultaneous measurements with an ionization chamber array (ICA) and EPID were performed to separate beam and detector response characteristics. Three different pixel calibration meth- ods were demonstrated and compared for an example 'clinical IMRT field'. The dose response with the Elekta EPID for 'simple' segmented IMRT fields versus static fields agreed to within 2.5% for monitor unit (MU) ≥ 2. The dose response for the Siemens systems was difficult to interpret due to the poor reproducibility for segmented delivery, at MU ≤ 5, which was not observed with the standalone research EPID nor ICA on the same machine. The dose response measured under different acquisition settings and different linac/EPID combinations matched closely (≤ 1%), except for the Siemens EPID. Clinical IMRT EPID dosimetry implemented with the different pixel-to-dose calibration methods indicated that calibration at 20 MU provides equivalent results to implementing a ghosting correction model. The nonlinear dose response was consistent across both clinical EPIDs and the standalone research EPID, with the exception of the poor reproducibility seen with Siemens EPID images of IMRT fields. The nonlinear dose response was

  3. Performance of dichromate dosimetry systems in calibration and dose intercomparison

    This report presents the results of the High Dose Dosimetry Laboratory of Argentina during ten years of international intercomparisons for high dose with the International Dose Assurance Service (IDAS) of the IAEA, using the standard high dose dichromate dosimetry system, and the results of a high dose intercomparison regional exercise in which our Laboratory acted as a reference laboratory, using the standard high dose and low dose dichromate dosimetry system. (author)

  4. The DOE Laboratory Accreditation Program performance testing laboratory automated calibration verification program

    The Performance Testing Laboratory for the DOE Laboratory Accreditation Program (DOELAP) resides at the Radiological and Environmental Sciences Laboratory (RESL) on the Idaho National Engineering Laboratory (INEL). A system has been developed to verify the calibration of Cesium 137 irradiators using a reference class ionization chamber under computer control. The measurement system consists of irradiators, a Victoreen Model 415 ionization chamber, a Keithley Model 617 electrometer, a high voltage power supply, a VAXLAB microVAX II processor controller, a Fluke digital thermometer, a Heise digital barometer and an Optomux interface between the computer and irradiator. The ionization chamber is placed in an irradiation fixture which is affixed to the dosimeter phantom stand. The computer then executes a variety of steps to conduct the irradiation and measurement. The data taken over the last six months indicate that all of the irradiator geometries meet requirements in the governing standards

  5. Establishing a standard calibration methodology for MOSFET detectors in computed tomography dosimetry

    Purpose: The use of metal-oxide-semiconductor field-effect transistor (MOSFET) detectors for patient dosimetry has increased by ∼25% since 2005. Despite this increase, no standard calibration methodology has been identified nor calibration uncertainty quantified for the use of MOSFET dosimetry in CT. This work compares three MOSFET calibration methodologies proposed in the literature, and additionally investigates questions relating to optimal time for signal equilibration and exposure levels for maximum calibration precision. Methods: The calibration methodologies tested were (1) free in-air (FIA) with radiographic x-ray tube, (2) FIA with stationary CT x-ray tube, and (3) within scatter phantom with rotational CT x-ray tube. Each calibration was performed at absorbed dose levels of 10, 23, and 35 mGy. Times of 0 min or 5 min were investigated for signal equilibration before or after signal read out. Results: Calibration precision was measured to be better than 5%–7%, 3%–5%, and 2%–4% for the 10, 23, and 35 mGy respective dose levels, and independent of calibration methodology. No correlation was demonstrated for precision and signal equilibration time when allowing 5 min before or after signal read out. Differences in average calibration coefficients were demonstrated between the FIA with CT calibration methodology 26.7 ± 1.1 mV cGy−1 versus the CT scatter phantom 29.2 ± 1.0 mV cGy−1 and FIA with x-ray 29.9 ± 1.1 mV cGy−1 methodologies. A decrease in MOSFET sensitivity was seen at an average change in read out voltage of ∼3000 mV. Conclusions: The best measured calibration precision was obtained by exposing the MOSFET detectors to 23 mGy. No signal equilibration time is necessary to improve calibration precision. A significant difference between calibration outcomes was demonstrated for FIA with CT compared to the other two methodologies. If the FIA with a CT calibration methodology was used to create calibration coefficients for the eventual

  6. Establishing a standard calibration methodology for MOSFET detectors in computed tomography dosimetry

    Brady, S. L.; Kaufman, R. A. [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, Tennessee 38105 (United States)

    2012-06-15

    Purpose: The use of metal-oxide-semiconductor field-effect transistor (MOSFET) detectors for patient dosimetry has increased by {approx}25% since 2005. Despite this increase, no standard calibration methodology has been identified nor calibration uncertainty quantified for the use of MOSFET dosimetry in CT. This work compares three MOSFET calibration methodologies proposed in the literature, and additionally investigates questions relating to optimal time for signal equilibration and exposure levels for maximum calibration precision. Methods: The calibration methodologies tested were (1) free in-air (FIA) with radiographic x-ray tube, (2) FIA with stationary CT x-ray tube, and (3) within scatter phantom with rotational CT x-ray tube. Each calibration was performed at absorbed dose levels of 10, 23, and 35 mGy. Times of 0 min or 5 min were investigated for signal equilibration before or after signal read out. Results: Calibration precision was measured to be better than 5%-7%, 3%-5%, and 2%-4% for the 10, 23, and 35 mGy respective dose levels, and independent of calibration methodology. No correlation was demonstrated for precision and signal equilibration time when allowing 5 min before or after signal read out. Differences in average calibration coefficients were demonstrated between the FIA with CT calibration methodology 26.7 {+-} 1.1 mV cGy{sup -1} versus the CT scatter phantom 29.2 {+-} 1.0 mV cGy{sup -1} and FIA with x-ray 29.9 {+-} 1.1 mV cGy{sup -1} methodologies. A decrease in MOSFET sensitivity was seen at an average change in read out voltage of {approx}3000 mV. Conclusions: The best measured calibration precision was obtained by exposing the MOSFET detectors to 23 mGy. No signal equilibration time is necessary to improve calibration precision. A significant difference between calibration outcomes was demonstrated for FIA with CT compared to the other two methodologies. If the FIA with a CT calibration methodology was used to create calibration

  7. Calibration of a tertiary standard in N-ISO qualities for radioprotection and personal dosimetry

    Dosimetric calibration of radiation monitors and personal dosimeters in different radiological quantities are performed in order to obtain accurate measurements, for this reason the SSDL calculates the dosimetry calibration factor and its associated uncertainty, for each range of use. The calibration factor is performed using the known radiation field method and its uncertainty is calculated according to the ISO recommendations. The SSDL calculates the expanded uncertainty (Uc) with a coverage factor that provides a level of not less than 95 % of confidence. (authors).

  8. MODIFIED LIULIN DETECTOR CALIBRATION FOR ONBOARD AIRCRAFT DOSIMETRY MEASUREMENTS

    Ambrožová, Iva; Krist, Pavel; Kubančák, Ján; Ploc, Ondřej; Kyselová, Dagmar

    Vol. 34. Bratislava: SMU - Faculty of Public Health, 2014. s. 60-60. ISBN 978-80-89384-08-2. [XXXVI.Dny radiační ochrany. 10.11.2014-14.11.2014, Poprad] Institutional support: RVO:61389005 Keywords : dosimetry * aircraft * detector Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  9. Standardization of the calibration of brachytherapy sources at the IAEA dosimetry laboratory

    A new service to SSDLs has been initiated at the IAEA Dosimetry Laboratory for providing calibrations of well-type ionisation chambers, used in brachytherapy applications, which are traceable to the International Measurement System. Considering that the most common radionuclide used in the developing countries is 137Cs, two such sources of the type used for gynaecological intracavitary applications have been purchased by the Agency and calibrated at the National Institute of Standards and Technology (NIST), USA. These 137Cs reference sources together with a well-type ionization chamber constitute the IAEA brachytherapy dosimetry standard. Based on the recommendations by a group of experts, a method has been developed for transferring calibrations to SSDLs which is described in this paper. The method is based on the acquisition by the SSDLs of sources and equipment similar to those at the IAEA. The well-type chamber is to be calibrated at the IAEA Dosimetry Laboratory, and this will be used at the SSDL to calibrate its own reference sources. These sources can in turn by used to calibrate well-type chambers from hospital users and to calibrate other type of sources by performing measurements in air. In order to standardize the procedures for the two methods and to provide guidance to the SSDLs, measurements have been carried out at the IAEA Dosimetry Laboratory. The reproducibility of the two type of measurements has been found to be better than 0.5%, and the uncertainty of calibrations estimated to be less than 1.5% (one standard deviation). (author). 8 refs, 8 figs, 2 tabs

  10. Validating dose rate calibration of radiotherapy photon beams through IAEA/WHO postal audit dosimetry service

    In external beam radiation therapy (EBRT), the quality assurance (QA) of the radiation beam is crucial to the accurate delivery of the prescribed dose to the patient. One of the dosimetric parameters that require monitoring is the beam output, specified as the dose rate on the central axis under reference conditions. The aim of this project was to validate dose rate calibration of megavoltage photon beams using the International Atomic Energy Agency (IAEA)/World Health Organisation (WHO) postal audit dosimetry service. Three photon beams were audited: a 6 MV beam from the low-energy linac and 6 and 18 MV beams from a dual high-energy linac. The agreement between our stated doses and the IAEA results was within 1% for the two 6 MV beams and within 2% for the 18 MV beam. The IAEA/WHO postal audit dosimetry service provides an independent verification of dose rate calibration protocol by an international facility. (author)

  11. Accreditation of testing laboratories in dosimetry: The use of a flexible scope at the competent Incorporation Measuring Body Juelich

    The accreditation of the Competent Incorporation Measuring Body at Juelich includes incorporation monitoring by means of direct measurements of the body activity as well as by means of indirect determination of the body activity by radiochemical analysis of excreta samples. In both testing areas, it proved to be very useful to have a flexible scope. In particular, the associated freedom in choosing testing procedures supports the continual improvement process of the laboratory. The modification of existing methods as well as the development and introduction of new procedures makes an immediate reaction to changed requirements feasible. At Juelich the use made out of the flexible scope included, e.g. the introduction of mathematical calibration in whole-body counting and the automation of sample preparation in radiochemical analysis. Advantages of the new procedures and modified methods include on the one hand the reduction of processing times, downtimes and hazard potentials on the other hand enhanced detection limits and improved cost-efficiency. In the result, it can be recommended to other qualified testing laboratories to go for a flexible scope. (authors)

  12. Calibration of a He accumulation fluence monitor for fast reactor dosimetry

    Ito, Chikara [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1997-03-01

    The helium accumulation fluence monitor (HAFM) has been developed for a fast reactor dosimetry. The HAFM measurement system was calibrated using He gas and He implanted samples and the measurement accuracy was confirmed to be less than 5%. Based on the preliminary irradiation test in JOYO, the measured He in the {sup 10}B type HAFM agreed well with the calculated values using the JENDL-3.2 library. (author)

  13. Comparison of calibration coefficients in the IAEA/WHO network of secondary standards dosimetry laboratories

    The paper describes the methodology, measurements, evaluation and analysis of the results of the IAEA programme for the comparison of calibration coefficients for radiotherapy dosimetry in the IAEA/World Health Organization network of secondary standards dosimetry laboratories (SSDLs). A pilot study was initiated in 1995 and the comparison programme started in 1997. In this programme ionization chambers that belong to the SSDLs are calibrated sequentially at the SSDL, at the IAEA and again at the SSDL. Since 1997, 42 SSDLs have participated in this comparison programme, although only 34 laboratories have effectively completed the process. The results from six participants were outside the acceptance limit set by the IAEA, but the follow-up process has improved the calibration procedures at these SSDLs. The results of the comparison, grouped according to the traceability of the SSDL measurements, are presented and discussed. As part of its own quality assurance programme, the IAEA participated in a regional comparison organized by the Sistema Interamericano de Metrologia (SIM, the regional metrology organization for the Americas) from 2000 to 2002, in which four SSDLs from Latin America also participated. Taking into account the differences in the primary standards to which the various SSDLs are traceable, the results of the IAEA-SIM comparison show good consistency and demonstrate the robustness of the international measurement system in radiotherapy dosimetry. (author)

  14. Dosimetry

    Eight articles treat the dosimetry. Two articles evaluate the radiation doses in specific cases, dosimetry of patients in radiodiagnosis, three articles are devoted to detectors (neutrons and x and gamma radiations) and a computer code to build up the dosimetry of an accident due to an external exposure. (N.C.)

  15. A suitability study of the fission product phantom and the bottle manikin absorption phantom for calibration of in vivo bioassay equipment for the DOELAP accreditation testing program

    Pacific Northwest laboratory (PNL) conducted an intercomparison study of the Fission Product phantom and the bottle manikin absorption (BOMAB) phantom for the US Department of Energy (DOE) to determine the consistency of calibration response of the two phantoms and their suitability for certification and use under a planned bioassay laboratory accreditation program. The study was initiated to determine calibration factors for both types of phantoms and to evaluate the suitability of their use in DOE Laboratory Accreditation Program (DOELAP) round-robin testing. The BOMAB was found to be more appropriate for the DOELAP testing program. 9 refs., 9 figs., 9 tabs

  16. A round-robin gamma stereotactic radiosurgery dosimetry interinstitution comparison of calibration protocols

    Purpose: Absorbed dose calibration for gamma stereotactic radiosurgery is challenging due to the unique geometric conditions, dosimetry characteristics, and nonstandard field size of these devices. Members of the American Association of Physicists in Medicine (AAPM) Task Group 178 on Gamma Stereotactic Radiosurgery Dosimetry and Quality Assurance have participated in a round-robin exchange of calibrated measurement instrumentation and phantoms exploring two approved and two proposed calibration protocols or formalisms on ten gamma radiosurgery units. The objectives of this study were to benchmark and compare new formalisms to existing calibration methods, while maintaining traceability to U.S. primary dosimetry calibration laboratory standards. Methods: Nine institutions made measurements using ten gamma stereotactic radiosurgery units in three different 160 mm diameter spherical phantoms [acrylonitrile butadiene styrene (ABS) plastic, Solid Water, and liquid water] and in air using a positioning jig. Two calibrated miniature ionization chambers and one calibrated electrometer were circulated for all measurements. Reference dose-rates at the phantom center were determined using the well-established AAPM TG-21 or TG-51 dose calibration protocols and using two proposed dose calibration protocols/formalisms: an in-air protocol and a formalism proposed by the International Atomic Energy Agency (IAEA) working group for small and nonstandard radiation fields. Each institution’s results were normalized to the dose-rate determined at that institution using the TG-21 protocol in the ABS phantom. Results: Percentages of dose-rates within 1.5% of the reference dose-rate (TG-21 + ABS phantom) for the eight chamber-protocol-phantom combinations were the following: 88% for TG-21, 70% for TG-51, 93% for the new IAEA nonstandard-field formalism, and 65% for the new in-air protocol. Averages and standard deviations for dose-rates over all measurements relative to the TG-21 + ABS

  17. A round-robin gamma stereotactic radiosurgery dosimetry interinstitution comparison of calibration protocols

    Drzymala, R. E., E-mail: drzymala@wustl.edu [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Alvarez, P. E. [Imaging and Radiation Oncology Core Houston, UT MD Anderson Cancer Center, Houston, Texas 77030 (United States); Bednarz, G. [Radiation Oncology Department, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15232 (United States); Bourland, J. D. [Department of Radiation Oncology, Wake Forest University, Winston-Salem, North Carolina 27157 (United States); DeWerd, L. A. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Ma, L. [Department of Radiation Oncology, University California San Francisco, San Francisco, California 94143 (United States); Meltsner, S. G. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Neyman, G. [Department of Radiation Oncology, The Cleveland Clinic Foundation, Cleveland, Ohio 44195 (United States); Novotny, J. [Medical Physics Department, Hospital Na Homolce, Prague 15030 (Czech Republic); Petti, P. L. [Gamma Knife Center, Washington Hospital Healthcare System, Fremont, California 94538 (United States); Rivard, M. J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Shiu, A. S. [Department of Radiation Oncology, University of Southern California, Los Angeles, California 90033 (United States); Goetsch, S. J. [San Diego Medical Physics, Inc., La Jolla, California 92037 (United States)

    2015-11-15

    Purpose: Absorbed dose calibration for gamma stereotactic radiosurgery is challenging due to the unique geometric conditions, dosimetry characteristics, and nonstandard field size of these devices. Members of the American Association of Physicists in Medicine (AAPM) Task Group 178 on Gamma Stereotactic Radiosurgery Dosimetry and Quality Assurance have participated in a round-robin exchange of calibrated measurement instrumentation and phantoms exploring two approved and two proposed calibration protocols or formalisms on ten gamma radiosurgery units. The objectives of this study were to benchmark and compare new formalisms to existing calibration methods, while maintaining traceability to U.S. primary dosimetry calibration laboratory standards. Methods: Nine institutions made measurements using ten gamma stereotactic radiosurgery units in three different 160 mm diameter spherical phantoms [acrylonitrile butadiene styrene (ABS) plastic, Solid Water, and liquid water] and in air using a positioning jig. Two calibrated miniature ionization chambers and one calibrated electrometer were circulated for all measurements. Reference dose-rates at the phantom center were determined using the well-established AAPM TG-21 or TG-51 dose calibration protocols and using two proposed dose calibration protocols/formalisms: an in-air protocol and a formalism proposed by the International Atomic Energy Agency (IAEA) working group for small and nonstandard radiation fields. Each institution’s results were normalized to the dose-rate determined at that institution using the TG-21 protocol in the ABS phantom. Results: Percentages of dose-rates within 1.5% of the reference dose-rate (TG-21 + ABS phantom) for the eight chamber-protocol-phantom combinations were the following: 88% for TG-21, 70% for TG-51, 93% for the new IAEA nonstandard-field formalism, and 65% for the new in-air protocol. Averages and standard deviations for dose-rates over all measurements relative to the TG-21 + ABS

  18. Establishment of a new calibration method of pencil ionization chamber for dosimetry in computed tomography

    Pencil ionization chambers are used for beam dosimetry in computed tomography equipment (CT). In this study, a new calibration methodology was established, in order to make the Calibration Laboratory of Instituto de Pesquisas Energeticas e Nucleares (LCI) suitable to international metrological standards, dealing with specific procedures for calibration of these chambers used in CT. Firstly, the setup for the new RQT radiation qualities was mounted, in agreement with IEC61267 from the International Electrotechnical Commission (IEC). After the establishment of these radiation qualities, a specific calibration methodology for pencil ionization chambers was set, according to Technical Report Series No. 457, from the International Atomic Energy Agency (IAEA), which describes particularities of the procedure to be followed by the Secondary Standard Dosimetry Laboratories (SSDL's), concerning to collimation and positioning related to the radiation beam. Initially, PPV (kV) measurements and the determination of copper additional filtrations were carried out, measuring the half value layers (HVL) recommended by the IEC 61267 standard, after that the RQT 8, RQT 9 and RQT 10 radiation quality references were established. For additional filters, aluminum and copper of high purity (around 99.9%) were used. RQT's in thickness of copper filters equivalent to the set 'RQR (Al) + Additional Filtration (Cu)' was directly found by an alternative methodology used to determine additional filtrations, which is a good option when RQR's have not the possibility of be setting up. With the establishment of this new methodology for the ionization pencil chambers calibration, the LCI is ready to calibrate these instruments according to the most recent international standards. Therefore, an improvement in calibration traceability, as well as in metrological services offered by IPEN to all Brazil is achieved. (author)

  19. Calibration of the Gamma Knife Perfexion using TG-21 and the solid water Leksell dosimetry phantom

    Purpose: To calibrate a Gamma Knife (GK) Perfexion using TG-21 with updated chamber-dependent values for modern microionization chambers in the new solid water Leksell dosimetry phantom. This work illustrates a calibration method using commercially available equipment, instruments, and an established dosimetry protocol that may be adopted at any GK center, thus reducing the interinstitutional variation in GK calibration. The calibration was verified by three third-party dosimetry checks. In addition, measurements of the relative output factors are presented and compared to available data and the new manufacturer-provided relative output factors yet to be released. Methods: An absolute dose calibration based on the TG-21 formalism, utilizing recently reported phantom material and chamber-dependent factors, was performed using a microionization chamber in a spherical solid water phantom. The result was compared to other calibration protocols based on TG-51. Independent verification of the machine output was conducted through M.D. Anderson Dosimetry Services (MDADS), using thermoluminescent dosimeters (TLDs) in an anthropomorphic head phantom; the Radiological Physics Center (RPC), using TLDs in the standard Elekta ABS plastic calibration phantom (gray phantom), included with the GK; and through a collaborative international calibration survey by the University of Pittsburgh Medical Center (UPMC) using alanine dosimeters, also in the gray phantom. The alanine dosimeters were read by the National Institute of Standards and Technology. Finally, Gafchromic EBT film was used to measure relative output factors and these factors were compared to values reported in the literature as well as new values announced for release by Elekta. The films were exposed in the solid water phantom using an included film insert accessory. Results: Compared to the TG-21 protocol in the solid water phantom, the modified and unmodified TG-51 calibrations resulted in dose rates which were 1

  20. Calibration in medical diagnostic beams at the Swedish secondary standard dosimetry laboratory

    New diagnostic X-ray beams based on the IEC standard no. 1267 are now available at the Secondary Standard Dosimetry Laboratory in Sweden. These beams are alternatives to the ISO narrow qualities and BIPM qualities that until now have been used for calibration of diagnostic instruments. A procedure differing somewhat from the IEC standard but following the primary radiation standards laboratory at PTB has been used for defining the radiation quality. This report describes the characteristics of the new radiation beams and the estimated effect on calibration factors due to the change in radiation quality. The effect on existing calibration beams due to the reconstruction of filter wheels has been investigated concerning scattered radiation, half-value layers and air kerma rates

  1. Calibration of activation detectors in a monoenergetic neutron beam. Contribution to criticality dosimetry

    Activation detectors have been calibrated for critical dosimetry applications. Measurements are made using a monoenergetic neutron flux. 14 MeV neutrons obtained par (D-T) reaction are produced by 150 kV accelerator. Neutron flux determined by different methods leads us to obtain an accuracy better than 6%. The present dosimetric system (Activation Neutron Spectrometer - SNAC) gives few informations in the (10 keV - 2 MeV) energetic range. The system has been improved and modified so that SNAC detectors must be read out by gamma spectrometer

  2. ESR dosimetry in calibration intercomparisons with high-energy photons and electrons

    Olsen, K.J. (University Hospital of Copenhagen, Herlev (Denmark)); Hansen, J.W. (Risoe National Lab., Roskilde (Denmark)); Waligorski, M.P.R. (Institute of Nuclear Physics, Cracow (Poland))

    1989-01-01

    When alanine is exposed to radiation, stable free radicals are produced which may be measured by electron spin resonance (ESR) spectroscopy. Our dosimeters consist of L-{alpha}-alanine mixed with 5% polyvinyl pyrrolidone, compacted in the shape of 2-mm thick cylinders of 4.5 mm diameter. The alanine dosimeters were exposed to 0.25 to 16-MV {sub p} X-ray beams and 6 to 20-MeV electron beams and measured at Riso National Laboratory. Doses were determined by comparison with alanine dosimeters exposed to {sup 60}Co {gamma}-rays calibrated with Fricke dosimetry. At absorbed doses above 10 Gy, the standard deviation for the dose measurements was 1%. Dosimetry comparisons better than 2% at the 95% confidence level are possible. The dosimeters are easy to handle, robust and cheap, and may be read repeatedly. Fading after 100 Gy of {sup 60}Co {gamma}-rays and Linac-produced X-ray and electron beams is less than 2 and 6% in 4 years, respectively. Alanine dosimeters are useful for dosimetry comparisons both for photons and electrons, and the negligible fading make them ideal for documentation of patient doses in radiation therapy. (author).

  3. A method for automating calibration and records management for instrumentation and dosimetry

    Current industry requirements are becoming more stringent on quality assurance records and documentation for calibration of instruments and dosimetry. A novel method is presented here that will allow a progressive automation scheme to be used in pursuit of that goal. This concept is based on computer-controlled irradiators that can act as stand-alone devices or be interfaced to other components via a computer local area network. In this way, complete systems can be built with modules to create a records management system to meet the needs of small laboratories or large multi-building calibration groups. Different database engines or formats can be used simply by replacing a module. Modules for temperature and pressure monitoring or shipping and receiving can be added, as well as equipment modules for direct IEEE-488 interface to electrometers and other instrumentation

  4. Calibration curves for biological dosimetry; Curvas de calibracion para dosimetria biologica

    Guerrero C, C.; Brena V, M. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail cgc@nuclear.inin.mx

    2004-07-01

    The generated information by the investigations in different laboratories of the world, included the ININ, in which settles down that certain class of chromosomal leisure it increases in function of the dose and radiation type, has given by result the obtaining of calibrated curves that are applied in the well-known technique as biological dosimetry. In this work is presented a summary of the work made in the laboratory that includes the calibrated curves for gamma radiation of {sup 60} Cobalt and X rays of 250 k Vp, examples of presumed exposure to ionizing radiation, resolved by means of aberration analysis and the corresponding dose estimate through the equations of the respective curves and finally a comparison among the dose calculations in those people affected by the accident of Ciudad Juarez, carried out by the group of Oak Ridge, USA and those obtained in this laboratory. (Author)

  5. A method for automating calibration and records management for instrumentation and dosimetry

    O`Brien, J.M. Jr.; Rushton, R.O.; Burns, R.E. Jr. [Atlan-Tech, Inc., Roswell, GA (United States)

    1993-12-31

    Current industry requirements are becoming more stringent on quality assurance records and documentation for calibration of instruments and dosimetry. A novel method is presented here that will allow a progressive automation scheme to be used in pursuit of that goal. This concept is based on computer-controlled irradiators that can act as stand-alone devices or be interfaced to other components via a computer local area network. In this way, complete systems can be built with modules to create a records management system to meet the needs of small laboratories or large multi-building calibration groups. Different database engines or formats can be used simply by replacing a module. Modules for temperature and pressure monitoring or shipping and receiving can be added, as well as equipment modules for direct IEEE-488 interface to electrometers and other instrumentation.

  6. Dosimetry

    The fundamental units of dosimetry are defined, such as exposure rate, absorbed dose and equivalent dose. A table is given of relative biological effectiveness values for the different types of radiation. The relation between the roentgen and rad units is calculated and the concepts of physical half-life, biological half-life and effective half-life are discussed. Referring to internal dosimetry, a mathematical treatment is given to β particle-and γ radiation dosimetry. The absorbed dose is calculated and a practical example is given of the calculation of the exposure and of the dose rate for a gama source

  7. Calibration of survey meters at the Algerian Secondary Standard Dosimetry Laboratory

    Full text: The Algerian Secondary Standard Dosimetry Laboratory, which became a Regional AFRA Designated Centre for French spoken countries, in the field of calibration since 2005, has developed and implemented methodologies for the calibration of radiation protection instruments such as survey meters. These instruments were initially calibrated in terms of air kerma free in air (NK) in 60Co, 137Cs gamma radiations. Although the recommended calibration quantity is H*(10) (Sv/h), most of instruments measure different physical quantities and problems about the expression of calibration factor in the calibration certificates are always raised. In order to switch to calibrations in terms of H*(10), a feasibility study was performed using instruments submitted for calibration at the SSDL. This paper presents the variation of the calibration coefficients, Fc, obtained since 2005 for three types of survey meters. The uncertainty components involved in the determination of Fc are analysed in details. Material and method: This study included the most used survey meters in Algeria and received at the SSDL in 2005 and 2006 which consist of 127 survey-meters of type Automess (different models), 80 Ludlum model 3 and 23 Graetz X 5 DE. Calibrations were performed using the beam output decay method. This output was determined with the Reference Standard chamber of type NE 2575 in 2005 and LS01 in 2006, both calibrated at the IAEA calibration laboratory. The average calibration coefficients, Fc, which converts the instruments reading to ambient equivalent absorbed dose, are calculated and the relative standard deviations assessed. The variation of calibration coefficients, for each type of instruments, is compared to the overall stated uncertainty for this coefficient. Results and discussion: The mean calibration coefficients in terms of H*(10) were lying from 0.993 ± 2.55% and 1.039 ± 3.16% for the Automess survey meters and from . The results are 1.215 ± 5.93%, 1.149 ± 14

  8. Assuring the quality of the mammography calibrations in Cuban laboratory by comparison with Greek dosimetry standard

    The Secondary Standard Dosimetry Laboratory (SSDL) of Cuba has recently worked on preparation of the dissemination proposal of air kerma quantities for dose measurements at mammography beams into the country. This work was supported by IAEA coordinated research project. The X-ray equipment available at the laboratory is based on tungsten anode, and then the recommended RQR-M series based on molybdenum target and specified in IEC 61267 cannot be established at the SSDL. The calibration of the reference class chamber with flat response in any beams on mammography range is an option suggested in TRS 457 when not all radiation qualities are available. As an alternative some authors have suggested the use of radiation qualities based on tungsten anode and defined by IEC 1223-3-2, The Radcal 10X6M chamber was designated as secondary standard of the SSDL. The chamber was calibrated over the IEC 1223-3-2 range in the primary laboratory of Austria (BEV). The designation and calibration of the secondary standard was followed by the establishment of the IEC 1223-3-2 qualities at the SSDL of Cuba and preparation of the calibration procedures. Before introducing the calibrations by alternative method it was necessary to test the quality of the results provided by SSDL of Cuba to confirm both if this procedure can be properly operated by laboratory and the needs of customer are met. For this goal it was found the experienced laboratory from Greece that use appropriate X-ray spectra for calibration of mammography dosimeters. The Hellenic Ionizing Radiation Calibration Laboratory (HIRCL) of Greece maintains the MAGNA Ref 92650 chamber as secondary standard traceable to PTB in RQR-M qualities based on molybdenum target. The X-ray system used is the clinical mammography unit with some modifications to fit the needs of calibrations. The laboratories were agreed to initiate a bilateral comparison exercise to evaluate whether the results of calibration of both laboratories are similar

  9. Dose levels of the occupational radiation exposures in Poland based on results from the accredited dosimetry service at the IFJ PAN, Krakow.

    Budzanowski, Maciej; Kopeć, Renata; Obryk, Barbara; Olko, Paweł

    2011-03-01

    Individual dosimetry service based on thermoluminescence (TLD) detectors has started its activity at the Institute of Nuclear Physics (IFJ) in Krakow in 1965. In 2002, the new Laboratory of Individual and Environment Dosimetry (Polish acronym LADIS) was established and underwent the accreditation according to the EN-PN-ISO/IEC 17025 standard. Nowadays, the service is based on the worldwide known standard thermoluminescent detectors MTS-N (LiF:Mg,Ti) and MCP-N (LiF:Mg,Cu,P), developed at IFJ, processed in automatic thermoluminescent DOSACUS or RE2000 (Rados Oy, Finland) readers. Laboratory provides individual monitoring in terms of personal dose equivalent H(p)(10) and H(p)(0.07) in photon and neutron fields, over the range from 0.1 mSv to 1 Sv, and environmental dosimetry in terms of air kerma K(a) over the range from 30 μGy to 1 Gy and also ambient dose equivalent H*(10) over the range from 30 μSv to 1 Sv. Dosimetric service is currently performed for ca. 3200 institutions from Poland and abroad, monitored on quarterly and monthly basis. The goal of this paper is to identify the main activities leading to the highest radiation exposures in Poland. The paper presents the results of statistical evaluation of ∼ 100,000 quarterly H(p)(10) and K(a) measurements performed between 2002 and 2009. Sixty-five per cent up to 90 % of all individual doses in Poland are on the level of natural radiation background. The dose levels between 0.1 and 5 mSv per quarter are the most frequent in nuclear medicine, veterinary and industrial radiography sectors. PMID:21183549

  10. A global calibration model for a-Si EPIDs used for transit dosimetry.

    Nijsten, S M J J G; van Elmpt, W J C; Jacobs, M; Mijnheer, B J; Dekker, A L A J; Lambin, P; Minken, A W H

    2007-10-01

    Electronic portal imaging devices (EPIDs) are not only applied for patient setup verification and detection of organ motion but are also increasingly used for dosimetric verification. The aim of our work is to obtain accurate dose distributions from a commercially available amorphous silicon (a-Si) EPID for transit dosimetry applications. For that purpose, a global calibration model was developed, which includes a correction procedure for ghosting effects, field size dependence and energy dependence of the a-Si EPID response. In addition, the long-term stability and additional buildup material for this type of EPID were determined. Differences in EPID response due to photon energy spectrum changes have been measured for different absorber thicknesses and field sizes, yielding off-axis spectrum correction factors based on transmission measurements. Dose measurements performed with an ionization chamber in a water tank were used as reference data, and the accuracy of the dosimetric calibration model was determined for a large range of treatment conditions. Gamma values using 3% as dose-difference criterion and 3 mm as distance-to-agreement criterion were used for evaluation. The field size dependence of the response could be corrected by a single kernel, fulfilling the gamma evaluation criteria in case of virtual wedges and intensity modulated radiation therapy fields. Differences in energy spectrum response amounted up to 30%-40%, but could be reduced to less than 3% using our correction model. For different treatment fields and (in)homogeneous phantoms, transit dose distributions satisfied in almost all situations the gamma criteria. We have shown that a-Si EPIDs can be accurately calibrated for transit dosimetry purposes. PMID:17985633

  11. A global calibration model for a-Si EPIDs used for transit dosimetry

    Electronic portal imaging devices (EPIDs) are not only applied for patient setup verification and detection of organ motion but are also increasingly used for dosimetric verification. The aim of our work is to obtain accurate dose distributions from a commercially available amorphous silicon (a-Si) EPID for transit dosimetry applications. For that purpose, a global calibration model was developed, which includes a correction procedure for ghosting effects, field size dependence and energy dependence of the a-Si EPID response. In addition, the long-term stability and additional buildup material for this type of EPID were determined. Differences in EPID response due to photon energy spectrum changes have been measured for different absorber thicknesses and field sizes, yielding off-axis spectrum correction factors based on transmission measurements. Dose measurements performed with an ionization chamber in a water tank were used as reference data, and the accuracy of the dosimetric calibration model was determined for a large range of treatment conditions. Gamma values using 3% as dose-difference criterion and 3 mm as distance-to-agreement criterion were used for evaluation. The field size dependence of the response could be corrected by a single kernel, fulfilling the gamma evaluation criteria in case of virtual wedges and intensity modulated radiation therapy fields. Differences in energy spectrum response amounted up to 30%-40%, but could be reduced to less than 3% using our correction model. For different treatment fields and (in)homogeneous phantoms, transit dose distributions satisfied in almost all situations the gamma criteria. We have shown that a-Si EPIDs can be accurately calibrated for transit dosimetry purposes

  12. Optimization of MOSFET-type sensor calibration for the implementation of in vivo dosimetry in stereotactic radiosurgery; Optimisation de la calibration de capteurs de type MOSFET pour la mise en oeuvre de la dosimetrie in vivo en radiochirurgie stereotaxique

    Sors, A. [Laboratoire d' etude et de recherche en imagerie spatiale et medicale, universite Paul-Sabatier, 31 - Toulouse (France); Cassol, E.; Duthil, P. [Unite de radiophysique et de radioprotection, CHU Toulouse, 31 (France); Cassol, E.; Lotterie, J.A.; Berry, I.; Franceries, X. [Inserm UMRS 825, 31 - Toulouse (France); Hallil, A. [Best Medical Canada, Ottawa (Canada); Sors, A.; Latorzeff, I.; Lotterie, J.A.; Redon, A.; Berry, I. [Centre de radiochirurgie stereotaxique, CHU Rangueil, 31 - Toulouse (France); Latorzeff, I.; Redon, A.; Berry, I. [Groupe Oncorad Garonne, 31 - Toulouse (France); Sors, A.; Cassol, E.; Hallil, A.; Latorzeff, I.; Duthil, P.; Lotterie, J.A.; Redon, A.; Berry, I.; Franceries, X. [Universite Paul-Sabatier, Toulouse-3, 31 - Toulouse (France)

    2010-10-15

    Within the frame of a project of assessment of in vivo dosimetry methods in stereotactic radiosurgery delivering an irradiation by a conformational dynamic arc therapy technique, the authors more precisely report the assessment and optimization of the calibration of MOSFET and micro MOSFET sensors. Measurements are performed on a Navel's system equipped with a multi-blade collimator. Short communication

  13. Development and calibration of a routine dosimetry system for radiation processing

    The development and calibration of a routine dosimetry system based on commercial, low cost photodiode (SFH 206) are presented in this work. The dosimeter probe was designed to operate unbiased in the direct current mode. The radiations were performed with Cobalt-60 Panoramic Irradiator facility in the dose-rate range of 8.1 Gy/h - 125 Gy/h. The photocurrents generated in the device, in each dose-rate, were registered with a digital electrometer and stored during the exposure time. The current response of the diode was measured as a function of the time in steps from 1 Gy up to 200 Gy with accumulated dose up to 15 kGy. In this range, the dose-response of the diode, given by the charge as function of dose, was linear with correlation coefficient better than 0.998. These results were compared with those obtained using Gafchromic film dosimetry often used in routine. To monitor possible gamma radiation effects produced on the diode, the current and charge sensitivities were measured as a function of the absorbed dose. For doses up to 15 kGy, it was not observed any radiation damage what confirms the reproducibility of the diode response better than 3 %. Finally, due to the small experimental errors ( 5% ) and good spatial resolution of the diode it was possible to measure the transit dose due to the movement of the Cobalt-60 radioactive source as well the dose rate mapping in the Panoramic Irradiator. (author)

  14. Methods of measurement and calibration in personnel dosimetry for external irradiation: presentation of the concept and the results of a test programme in Switzerland

    In 1986 the Swiss working group on personnel dosimetry issued a recommendation on methods of calibration and measurement in personnel dosimetry for external radiation, based on ICRU report 39. The aim of the report was to give detailed and pragmatic guidance to the dosimetry services and the calibration labs. In the recommendation a definition is given for primary and secondary limited quantities, for calibration quantities and operational quantities as well as for their interrelationships. The second part of the report is a manual for the calibration and evaluation procedures for whole-body and extremity dosemeters for photon and electron radiation. Based on that recommendation an extended test programme has been performed for all dosimetry services in Switzerland. The results show that the legal introduction of the recommended concept has no severe consequences for the dosimetry services although a number of minor modifications are needed. (author)

  15. Calibration of dosimeters and survey instruments for photons at the Malaysian Secondary Standard Dosimetry Laboratory

    Radiation protection infrastructures are well established in Malaysia. The infrastructures include laws and regulations regarding the use of ionising radiations, regulatory body to enforce the regulations, the radiation protection services and radiation protection training capability. The Atomic Energy Licensing Board (AELB) is the regulatory body responsible for licensing and enforcement of the law and regulation while Malaysian Institute for Nuclear Technology Research (MINT) through its Secondary Standard Dosimetry Laboratory (SSDL) is to provide radiation protection services throughout the country. The laboratory facilitates the proper radiation calibration and verification of the instruments used for the measurement of radiation ensuring the safe use of nuclear technology. The rapid growth in the application of nuclear technology is obviously to be welcomed but there must be someway of ensuring that the safety aspects really meet the required standards. (J.P.N.)

  16. Calibration of brachytherapy sources. Guidelines on standardized procedures for the calibration of brachytherapy sources at Secondary Standard Dosimetry Laboratories (SSDLs) and hospitals

    Today, irradiation by brachytherapy is considered an essential part of the treatment for almost all the sites of cancer. With the improved localization techniques and treatment planning systems, it is now possible to have precise and reproducible dose delivery. However, the desired clinical results can only be achieved with a good clinical and dosimetric practice, i.e. with the implementation of a comprehensive quality assurance (QA) programme which includes detailed quality control procedures. As summarized in the present report, accidents in brachytherapy treatments have been caused due to the lack of traceable calibration of the sources, due to the incorrect use of quantities and units, or errors made in the dose calculation procedure. The International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources has established a requirement on the calibration of sources used for medical exposure. For sources used in brachytherapy treatments, a calibration traceable to a standards dosimetry laboratory is required. The present report deals with the calibration of brachytherapy sources and related quality control (QC) measurements, QC of ionization chambers and safety aspects related to the calibration procedures. It does not include safety aspects related to the clinical use of brachytherapy sources, which have been addressed in a recent IAEA publication, IAEA-TECDOC-1040, 'Design and Implementation of a Radiotherapy Programme: Clinical, Medical Physics, Radiation Protection and Safety Aspects'. The procedures recommended in this report yield traceability to internationally accepted standards. It must be realized, however, that a comprehensive QA programme for brachytherapy cannot rest on source calibration alone, but must ensure QC of all the equipment and techniques that are used for the dose delivery to the patient. The present publication incorporates the reports of several consultants meetings in the field of

  17. Neutron personnel dosimetry

    The current state-of-the-art in neutron personnel dosimetry is reviewed. Topics covered include dosimetry needs and alternatives, current dosimetry approaches, personnel monitoring devices, calibration strategies, and future developments

  18. Radiation dosimetry

    Hine, Gerald J; Hine, Gerald J

    1956-01-01

    Radiation Dosimetry focuses on the advancements, processes, technologies, techniques, and principles involved in radiation dosimetry, including counters and calibration and standardization techniques. The selection first offers information on radiation units and the theory of ionization dosimetry and interaction of radiation with matter. Topics include quantities derivable from roentgens, determination of dose in roentgens, ionization dosimetry of high-energy photons and corpuscular radiations, and heavy charged particles. The text then examines the biological and medical effects of radiation,

  19. Principles for the design and calibration of radiation protection dosemeters for operational and protection quantities for eye lens dosimetry

    The work package two of the ORAMED project-Collaborative Project (2008-2011) supported by the European Commission within its seventh Framework Programme-is devoted to the study of the eye lens dosimetry. A first approach is to implement the use of Hp(3) by providing new sets of conversion coefficients and well suited calibration and type test procedures. This approach is presented in other papers in the proceedings of this conference. Taking into account that the eye lens is an organ close to the surface of the body, another approach would be to directly estimate the absorbed dose to the eye lens, Dlens,est through a special calibration procedure although this quantity is not directly measurable. This paper is a methodological paper that tries to identify the critical aspects of a dosimetry in terms of Dlens. (authors)

  20. CT head-scan dosimetry in an anthropomorphic phantom and associated measurement of ACR accreditation-phantom imaging metrics under clinically representative scan conditions

    Brunner, Claudia C.; Stern, Stanley H.; Chakrabarti, Kish [U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993 (United States); Minniti, Ronaldo [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899 (United States); Parry, Marie I. [Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, Maryland 20889 (United States); Skopec, Marlene [National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892 (United States)

    2013-08-15

    Purpose: To measure radiation absorbed dose and its distribution in an anthropomorphic head phantom under clinically representative scan conditions in three widely used computed tomography (CT) scanners, and to relate those dose values to metrics such as high-contrast resolution, noise, and contrast-to-noise ratio (CNR) in the American College of Radiology CT accreditation phantom.Methods: By inserting optically stimulated luminescence dosimeters (OSLDs) in the head of an anthropomorphic phantom specially developed for CT dosimetry (University of Florida, Gainesville), we measured dose with three commonly used scanners (GE Discovery CT750 HD, Siemens Definition, Philips Brilliance 64) at two different clinical sites (Walter Reed National Military Medical Center, National Institutes of Health). The scanners were set to operate with the same data-acquisition and image-reconstruction protocols as used clinically for typical head scans, respective of the practices of each facility for each scanner. We also analyzed images of the ACR CT accreditation phantom with the corresponding protocols. While the Siemens Definition and the Philips Brilliance protocols utilized only conventional, filtered back-projection (FBP) image-reconstruction methods, the GE Discovery also employed its particular version of an adaptive statistical iterative reconstruction (ASIR) algorithm that can be blended in desired proportions with the FBP algorithm. We did an objective image-metrics analysis evaluating the modulation transfer function (MTF), noise power spectrum (NPS), and CNR for images reconstructed with FBP. For images reconstructed with ASIR, we only analyzed the CNR, since MTF and NPS results are expected to depend on the object for iterative reconstruction algorithms.Results: The OSLD measurements showed that the Siemens Definition and the Philips Brilliance scanners (located at two different clinical facilities) yield average absorbed doses in tissue of 42.6 and 43.1 m

  1. Calibration of photon and beta ray sources used in brachytherapy. Guidelines on standardized procedures at Secondary Standards Dosimetry Laboratories

    It has generally been recognized that international harmonization in radiotherapy dosimetry is essential. Consequently, the IAEA has given much effort to this, for example by publishing a number of reports in the Technical Reports Series (TRS) for external beam dosimetry, most notably TRS-277 and more recently TRS-398. Both of these reports describe in detail the steps to be taken for absorbed dose determination in water and they are often referred to as 'dosimetry protocols'. Similar to TRS-277, it is expected that TRS-398 will be adopted or used as a model by a large number of countries as their national protocol. In 1996, the IAEA established a calibration service for low dose rate (LDR) 137 Cs brachytherapy sources, which is the most widely used source for treatment of gynecological cancer. To further enhance harmonization in brachytherapy dosimetry, the IAEA published in 1999 IAEA-TECDOC-1079 entitled 'Calibration of Brachytherapy Sources. Guidelines on Standardized Procedures for the Calibration of Brachytherapy Sources at Secondary Standard Dosimetry Laboratories (SSDLs) and Hospitals'. The report was well received and was distributed in a large number of copies to the members of the IAEA/WHO network of SSDLs and to medical physicists working with brachytherapy. The present report is an update of the aforementioned TECDOC. Whereas TECDOC-1079 described methods for calibrating brachytherapy sources with photon energies at or above those of 192Ir, the current report has a wider scope in that it deals with standardization of calibration of all the most commonly used brachytherapy sources, including both photon and beta emitting sources. The latter sources have been in use for a few decades already, but their calibration methods have been unclear. Methods are also described for calibrating sources used in the rapidly growing field of cardiovascular angioplasty. In this application, irradiation of the vessel wall is done in an attempt to prevent restenosis after

  2. Optimization of MOSFET calibration for in vivo dosimetry in radiosurgery: reduction of measurement uncertainties in pre-clinical conditions; Optimisation de la calibration de MOSFET pour la dosimetrie in vivo en radiochirurgie: reduction des incertitudes de mesure en conditions precliniques

    Sors, A.; Berry, I.; Franceries, X. [UMR 825 ' imagerie cerebrale et handicaps neurologiques' , Inserm, Toulouse (France); Cassol, E.; Duthil, P. [Unite de radiophysique et de radioprotection, CHU de Toulouse, Toulouse (France); Hallil, A. [Best medical Canada, Ottawa (Canada); Latorzeff, I.; Lotterie, J.A. [Centre de radiochirurgie stereotaxique, CHU Rangueil, Toulouse (France); Redon, A. [Groupe Oncorad Garonne, Montauban (France)

    2011-10-15

    The objective of this study is to assess the conventional formulas of equivalent square for fields with irregular geometry, by transposing the optimized calibration method which has been previously developed, to micro-MOSFET. The study has been performed on a 6 MV Novalis apparatus equipped with micro-multi-blades collimators (BrainLab). The average dose bias reaches 2.66 per cent for all field sizes. Therefore, it appears that the joint use of the square inverse of distances and of conventional formulas of equivalent square results in an acceptable in vivo dosimetry precision. Short communication

  3. A comparison of in-air and in-water calibration of a dosimetry system used for radiation dose assessment in cancer therapy

    Arshed Waheed

    2010-01-01

    Full Text Available An accurate calibration of the therapy level radiation dosimetry system has a pivotal role in the accuracy of dose delivery to cancer patients. The two methods used for obtaining a tissue equivalent calibration of the system: air kerma calibration and its conversion to a tissue equivalent value (absorbed dose to water and direct calibration of the system in a water phantom, have been compared for identical irradiation geometry. It was found that the deviation between the two methods remained within a range of 0% to ±1.7% for the PTW UNIDOS dosimetry system. This means that although the recommended method is in-water calibration, under exceptional circumstances, in-air calibration may be used as well.

  4. Dosimetry in high-energy photon fields for the calibration of measuring instruments for radiation protection purposes

    This report describes the dosimetry in various reference photon fields with energies between 4.4 MeV and about 8 MeV. Two dosimetric quantities were chosen. The air kerma was determined from measurements without a phantom and the absorbed dose to water from measurements with a phantom. This mean that the range of realization of the quantity air kerma has been extended from the energy of Co-60 photons to about 8 MeV. The results can serve as basis for the calibration of radiation protection dosemeters in nuclear power plants (0-16(n,p)N-16 reaction) with high energy photons. (orig./HP)

  5. Field calibration of PADC track etch detectors for local neutron dosimetry in man using different radiation qualities

    In order to quantify the dose from neutrons to a patient for contemporary radiation treatment techniques, measurements inside phantoms, representing the patient, are necessary. Published reports on neutron dose measurements cover measurements performed free in air or on the surface of phantoms and the doses are expressed in terms of personal dose equivalent or ambient dose equivalent. This study focuses on measurements of local neutron doses inside a radiotherapy phantom and presents a field calibration procedure for PADC track etch detectors. An initial absolute calibration factor in terms of Hp(10) for personal dosimetry is converted into neutron dose equivalent and additional calibration factors are derived to account for the spectral changes in the neutron fluence for different radiation therapy beam qualities and depths in the phantom. The neutron spectra used for the calculation of the calibration factors are determined in different depths by Monte Carlo simulations for the investigated radiation qualities. These spectra are used together with the energy dependent response function of the PADC detectors to account for the spectral changes in the neutron fluence. The resulting total calibration factors are 0.76 for a photon beam (in- and out-of-field), 1.00 (in-field) and 0.84 (out-of-field) for an active proton beam and 1.05 (in-field) and 0.91 (out-of-field) for a passive proton beam, respectively. The uncertainty for neutron dose measurements using this field calibration method is less than 40%. The extended calibration procedure presented in this work showed that it is possible to use PADC track etch detectors for measurements of local neutron dose equivalent inside anthropomorphic phantoms by accounting for spectral changes in the neutron fluence.

  6. Field calibration of PADC track etch detectors for local neutron dosimetry in man using different radiation qualities

    Haelg, Roger A., E-mail: rhaelg@phys.ethz.ch [Institute for Radiotherapy, Radiotherapie Hirslanden AG, Hirslanden Medical Center, Rain 34, CH-5000 Aarau (Switzerland); Besserer, Juergen [Institute for Radiotherapy, Radiotherapie Hirslanden AG, Hirslanden Medical Center, Rain 34, CH-5000 Aarau (Switzerland); Boschung, Markus; Mayer, Sabine [Division for Radiation Safety and Security, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Clasie, Benjamin [Department of Radiation Oncology, Massachusetts General Hospital, 30 Fruit Street, Boston, MA 02114 (United States); Kry, Stephen F. [Department of Radiation Physics, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030 (United States); Schneider, Uwe [Institute for Radiotherapy, Radiotherapie Hirslanden AG, Hirslanden Medical Center, Rain 34, CH-5000 Aarau (Switzerland); Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 204, CH-8057 Zurich (Switzerland)

    2012-12-01

    In order to quantify the dose from neutrons to a patient for contemporary radiation treatment techniques, measurements inside phantoms, representing the patient, are necessary. Published reports on neutron dose measurements cover measurements performed free in air or on the surface of phantoms and the doses are expressed in terms of personal dose equivalent or ambient dose equivalent. This study focuses on measurements of local neutron doses inside a radiotherapy phantom and presents a field calibration procedure for PADC track etch detectors. An initial absolute calibration factor in terms of H{sub p}(10) for personal dosimetry is converted into neutron dose equivalent and additional calibration factors are derived to account for the spectral changes in the neutron fluence for different radiation therapy beam qualities and depths in the phantom. The neutron spectra used for the calculation of the calibration factors are determined in different depths by Monte Carlo simulations for the investigated radiation qualities. These spectra are used together with the energy dependent response function of the PADC detectors to account for the spectral changes in the neutron fluence. The resulting total calibration factors are 0.76 for a photon beam (in- and out-of-field), 1.00 (in-field) and 0.84 (out-of-field) for an active proton beam and 1.05 (in-field) and 0.91 (out-of-field) for a passive proton beam, respectively. The uncertainty for neutron dose measurements using this field calibration method is less than 40%. The extended calibration procedure presented in this work showed that it is possible to use PADC track etch detectors for measurements of local neutron dose equivalent inside anthropomorphic phantoms by accounting for spectral changes in the neutron fluence.

  7. Radioluminescence (RL) probe dosimetry using Al2O3:C for precise calibration of beta sources applied in luminescence dating

    The radioluminescence (RL) phenomenon is widely known as prompt luminescence or fluorescence of synthetic materials, like Al2O3 and LiF as well as of natural dosimeter materials, like feldspar and quartz, during interaction with ionising radiation, especially electron rays. Almost all of these materials show increasing RL flux with increasing absorbed beta dose. Only potassium rich feldspars (microcline and orthoclase) show a RL emission at 1.45 eV of decreasing intensity with rising delivered dose. For a number of reasons, this RL emission is suitable for dating purposes. Accuracy and reproducibility of the RL dating method are much more advantageous compared to TL and OSL methods. Carbon doped Al2O3 (TLD 500) shows a much more higher RL intensity than, e.g., feldspar and the stability of the stored electrons as well as the linearity of RL yield versus primary electron energy, qualifies this dosimeter material to be a useful tool in source calibration, using radioluminescence. However, the accuracy of a luminescence dating method depends largely on the calibration of the used irradiation sources. To prevent calibration uncertainties due to the use of natural dosimeters with a high scattering of luminescence yield, a new method is suggested. This method bases on probe dosimetry using a very small amount of Al2O3:C as probe and, consequently, the material that should be calibrated (e.g. feldspar). The amount of Al2O3:C may disturb the electron fluence within the material to be calibrated only insignificantly. The sample mix is irradiated by an exactly known Gamma or Beta radiation source and the absorbed dose is treated as absorbed dose in the appropriated material. In contrast to conventional calibration methods, the suggested performance uses the dose dependent RL signal of Al2O3:C at 3.00 eV. This shows a good reproducibility, even with a tiny amount of the applied synthetic probe material. (author)

  8. Calibration of semiconductors diodes for in vivo dosimetry in total body irradiation treatments; Calibracao de diodos semicondutores para dosimetria in vivo em tratamentos de irradiacao de corpo inteiro

    Oliveira, Fernanda F.; Costa, Alessandro M.; Ghilardi Netto, Thomaz, E-mail: ferretti.oliveira@gmail.com [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Ciencias e Letras. Departamento de Fisica; Amaral, Leonardo L. [Universidade de Sao Paulo (HCFMRP/USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas. Servico de Radioterapia

    2012-08-15

    This paper presents the results of in vivo dosimetry with p-type semiconductors diodes, EDP-15 (Scanditronix Wellhoefer) of two patients who underwent total body irradiation treatments, at Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto University of Sao Paulo (HCFMRP-USP). The diodes were well calibrated and the calibration factors were determined with the aid of a reference ionization chamber (FC065, IBA dosimetry, sensitive volume of 0.65 cm{sup 3}).The calibration was performed in a Total Body Irradiation (TBI) setup, using solid water phantoms. Different lateral thicknesses from one patient were simulated and then the calibration factors were determined by means of maximum depth dose readings (half of the lateral thickness). The response difference between diode readings and the prescribed dose for both treatments was below 4%. This difference is in agreement as recommended by International Commission on Radiation Units (ICRU), which is {+-}5%. (author)

  9. DOE standard: The Department of Energy Laboratory Accreditation Program administration

    This technical standard describes the US Department of Energy Laboratory Accreditation Program (DOELAP), organizational responsibilities, and the accreditation process. DOELAP evaluates and accredits personnel dosimetry and radiobioassay programs used for worker monitoring and protection at DOE and DOE contractor sites and facilities as required in Title 10, Code of Federal Regulations, Part 835, Occupational Radiation Protection. The purpose of this technical standard is to establish procedures for administering DOELAP and acquiring accreditation

  10. H p(0.07) photon dosemeters for eye lens dosimetry: Calibration on a rod vs. a slab phantom

    In recent years, several papers dealing with eye lens dosimetry have been published as epidemiological studies are implying that the induction of cataracts occurs even at eye lens doses of less than 500 mGy. For that reason, the necessity to monitor the eye lens may become more important than it was before. However, only few dosemeters for the appropriate quantity Hp(3) are available. Partial-body dosemeters are usually designed to measure the quantity Hp(0.07) calibrated on a rod phantom representing a finger while a slab phantom much better represents the head. Therefore, in this work it was investigated whether dosemeters designed for the quantity Hp(0.07) calibrated on a rod phantom can also be worn on the head (close to the eyes) and still deliver correct results (Hp(0.07) on a head). For that purpose, different types of partial-body dosemeters from routine use were irradiated at different photon energies on both a rod and a slab phantom. It turned out that their response values are within ±5% independent of the phantom if the quantity value for the respective phantom is used. Thus, partial-body dosemeters designed for the quantity Hp(0.07) calibrated on a rod phantom may be worn on the head and used to monitor the eye lens dose due to photon radiation via the measurement of Hp(0.07) on the head. (authors)

  11. Ophthalmic applicators: An overview of calibrations following the change to SI units

    Since the NIST dose to water standard for 90Sr/90Y ophthalmic applicators was introduced, numerous sources have undergone calibration either at NIST or at the University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL). From 1997 to 2008, 222 of these beta-emitting sources were calibrated at the UWADCL, and prior reference source strength values were available for 149 of these sources. A survey of UWADCL ophthalmic applicator calibrations is presented here, demonstrating an average discrepancy of -19% with a standard deviation of ±16% between prior reference values and the NIST-traceable UWADCL absorbed dose to water calibrations. Values ranged from -49% to +42%.

  12. Accreditation of environmental TLD dosimetry system: validation and uncertainty of the method; Acreditacion de sistema de dosimetria ambiental TLD: validacion e incertumbre del metodo

    Rodriguez Jimenez, R.; Romero Gutierrez, A. M.; Lopez Moyano, J. L.

    2013-07-01

    he work shows the results obtained in the validation of the method used, and the calculation of uncertainty. The authors' goal is to spread the practical experience gained during the accreditation process, paying special attention to the process of validation of the method and the estimation of the uncertainty of the dosimetric systems. (Author)

  13. Improvement of the WBC calibration of the Internal Dosimetry Laboratory of the CDTN/CNEN using MCNPX code

    Guerra P, F.; Heeren de O, A. [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Programa de Pos Graduacao em Ciencias e Tecnicas Nucleares, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Melo, B. M.; Lacerda, M. A. S.; Da Silva, T. A.; Ferreira F, T. C., E-mail: tcff01@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear, Programa de Pos Graduacao / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    The Plan of Radiological Protection licensed by the National Nuclear Energy Commission - CNEN in Brazil includes the risks of assessment of internal and external exposure by implementing a program of individual monitoring which is responsible of controlling exposures and ensuring the maintenance of radiation safety. The Laboratory of Internal Dosimetry of the Center for Development of Nuclear Technology - LID/CDTN is responsible for routine monitoring of internal contamination of the Individuals Occupationally Exposed (IOEs). These are, the IOEs involved in handling {sup 18}F produced by the Unit for Research and Production of Radiopharmaceuticals sources; as well a monitoring of the entire body of workers from the Research Reactor TRIGA IPR-R1/CDTN or whenever there is any risk of accidental incorporation. The determination of photon emitting radionuclides from the human body requires calibration techniques of the counting geometries, in order to obtain a curve of efficiency. The calibration process normally makes use of physical phantoms containing certified activities of the radionuclides of interest. The objective of this project is the calibration of the WBC facility of the LID/CDTN using the BOMAB physical phantom and Monte Carlo simulations. Three steps were needed to complete the calibration process. First, the BOMAB was filled with a KCl solution and several measurements of the gamma ray energy (1.46 MeV) emitted by {sup 40}K were done. Second, simulations using MCNPX code were performed to calculate the counting efficiency (Ce) for the BOMAB model phantom and compared with the measurements Ce results. Third and last step, the modeled BOMAB phantom was used to calculate the Ce covering the energy range of interest. The results showed a good agreement and are within the expected ratio between the measured and simulated results. (Author)

  14. Calibration of Monte Carlo simulation code to low voltage electron beams through radiachromic dosimetry

    A simple multilayer slab model of an electron beam using the ITS/TIGER code can consistently account for about 80% of the actual dose delivered by a low voltage electron beam. The difference in calculated values is principally due to the 3D hibachi structure which blocks 22% of the beam. A 3D model was constructed using the ITS/ACCEPT code to improve upon the TIGER simulations. A rectangular source description update to the code and reproduction of all key geometric elements involved, including the hibachi, accounted for 90-95% of the dose received by routine dosimetry

  15. Calibration process of survey meters and dosemeters at Standard Dosimetry Laboratory, Nuclear Energy Unit, Malaysia

    Techniques of calibration and its possible uses are reviewed and discussed. Three main techniques identified are substitution, simultaneous irradiation and inverse square law. The scope of application of each technique is discussed in detail. In addition, tests which are performed on the calibrated dosemeters including energy dependence, angular dependence as well as linearity are explained. For the above purposes, photon radiations from 30 keV to 1250 keV were used. The radiations are obtained by means of an X-ray machine, PHILIPS Model MCN 32, Cs 137 and C60. At the end of the report, several forms tht are required for giving the calibration services are attached. (author)

  16. Electron beam dosimetry. Calibration and use of plane parallel chambers following IAEA TRS-381 recommendations

    Using different plane parallel chamber types (NACP-02, PTW Roos and PTW Markus), and a cylindrical chamber NE-2571 as reference, the IAEA TRS-381 Code of Practice has been compared with the AAPM TG-39 dosimetry protocol for plane parallel chambers. ND,airpp was determined following the 60Co in-phantom method and the electron beam method described in TRS-381, using water, PMMA and RMI-457 Solid Water phantoms. Differences were smaller than 0.5% between the two methods except for the PTW Roos chamber where the discrepancy was about 1.5%. The absorbed dose to water was determined according to the procedures and data of each protocol for electron beams between 4 and 18 MeV. Differences in absorbed dose were less than 1% when measurements were made in water, but a deviation of up to 2% was found between TRS-381 and TG-39 when PMMA phantoms were used. To validate the results obtained and to investigate differences between plastic and water phantoms in electron beam dosimetry, the scaling factor Cpl and the fluence correction factor hm for PMMA and solid water RMI-457 were measured and compared to the data in TRS-381. Good agreement was found for Cpl, but only when the plastics density were taken into account. The experimental values of hm have a large uncertainty but for PMMA a trend for hm being lower than in TRS-381 has been obtained. (author)

  17. Calibration System for Dosimetry and Radioactivity of Beta-Emitting Sources

    Choi, Chang Heon; Ye, Sungjoon [Seoul National Univ., Seoul (Korea, Republic of); Son, Kwangjae; Park, Uljae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-07-01

    This study aims to develop a calibration system for radioactivity of beta sources using a calibration constant which derived from comparing measurement and simulation. It is hard to measure the activity of beta emitter isotope due to self absorption and scattering. So the activity involves high levels of uncertainty. The surface dose of Sr/Y-90 standard isotope was measured using extrapolation chamber and calculated using Monte Carlo. The activity (4.077 kBq) of source was measured by NIST measurement assurance program. And several correction factors were calculated Monte Carlo method. The measurement result was corrected by correction factors. The calibration constant was defined as the ratio of surface dose to activity. It was 4.5Χ10{sup -8} and 6.52Χ10{sup -8} for measurement and Monte Carlo, respectively. There was about 15.4% difference in the calibration constant determined by the two techniques. The depth uncertainty makes the difference because of high dose gradients. Some correction factors have error due to scattering by detector geometry. A test source will be produced by HANARO. The activity will be calculated using calibration constant. The activity will be performed cross-calibration with NIST. Finally, the system will provide accurate information of sources.

  18. Experimental procedure for the manufacture and calibration of polyacrylamide gel (PAG) for magnetic resonance imaging (MRI) radiation dosimetry

    A simple methodology for the manufacture and calibration of polyacrylamide gel (PAG) for magnetic resonance imaging (MRI) radiation dosimetry is presented to enable individuals to undertake such work in a routine clinical environment. Samples of PAG were irradiated using a linear accelerator and imaged using a 0.5 T (22 MHz) Philips Gyroscan MRI scanner. The mean spin-lattice relaxation rate was measured using a 'turbo-mixed' sequence, consisting of a series of 90 deg. pulses, each followed by acquisition of a train of spin echoes. The mean sensitivity for five different batches of PAG in the range up to 10 Gy was calculated to be 0.0285 s-1 Gy-1 for the mean spin-lattice relaxation rate with a percentage standard deviation of 1.25%. The overall reproducibility between batches was calculated to be 2.69%. This methodology, which introduces the novel use of pre-filled nitrogen vials for calibration, has been used to develop techniques for filling anatomically shaped anthropomorphic phantoms. (author)

  19. NVLAP activities at Department of Defense calibration laboratories

    There are 367 active radiological instrument calibration laboratories within the U.S. Department of Defense (DoD). Each of the four services in DoD manages, operates, and certifies the technical proficiency and competency of those laboratories under their cognizance. Each service has designated secondary calibration laboratories to trace all calibration source standards to the National Institute of Standards and Technology. Individual service radiological calibration programs and capabilities, present and future, are described, as well as the measurement quality assurance (MQA) processes for their traceability. National Voluntary Laboratory Accreditation Program (NVLAP) programs for dosimetry systems are briefly summarized. Planned NVLAP accreditation of secondary laboratories is discussed in the context of current technical challenges and future efforts

  20. NVLAP activities at Department of Defense calibration laboratories

    Schaeffer, D.M. [Defense Nuclear Agency, Alexandria, VA (United States)

    1993-12-31

    There are 367 active radiological instrument calibration laboratories within the U.S. Department of Defense (DoD). Each of the four services in DoD manages, operates, and certifies the technical proficiency and competency of those laboratories under their cognizance. Each service has designated secondary calibration laboratories to trace all calibration source standards to the National Institute of Standards and Technology. Individual service radiological calibration programs and capabilities, present and future, are described, as well as the measurement quality assurance (MQA) processes for their traceability. National Voluntary Laboratory Accreditation Program (NVLAP) programs for dosimetry systems are briefly summarized. Planned NVLAP accreditation of secondary laboratories is discussed in the context of current technical challenges and future efforts.

  1. A reference current source for the calibration of current measuring systems in dosimetry using ionisation chambers

    This work describes a newly developed, easily handled current source containing one 90Sr + 90Y Y beta emitter. Four different currents from 7x10-11A to 4x10-14A are supplied. From 5 to 10 control measurements were performed for each of the four currents during a period of eight months. The standard deviation of the values of these control measurements, corrected to a reference air density and for radioactive decay, was between 0,07% and 0,4% with respect to the mean values obtained during the eight months. The relative standard deviation of the single values belonging to a control measurement carried out on one day under constant ambient conditions amounts to approximately one fourth of the values quoted above. The current source was utilized in a number of laboratories in the PTB and proved its reliability for checking current measuring systems in dosimetry with ionization chambers. (orig.)

  2. Design and fabrication of a multipurpose thyroid phantom for medical dosimetry and calibration

    A multipurpose anthropomorphic neck phantom was designed and fabricated for use in medical applications. The designed neck phantom is composed of seven elliptic cylindrical slices with a semi-major axis of 14 cm and a semi-minor axis of 12.5 cm, each having the thickness of 2 cm. The thyroid gland, bony part of the neck, and the windpipe were also built inside the neck phantom. For the purpose of medical dosimetry, some holes were drilled inside the phantom to accommodate the thermoluminescence dosemeters with different shapes and dimensions. For testing the quality of images in nuclear medicine, the thyroid gland was built separately to accommodate the radioactive iodine. Finally, the nuclear medicine images were obtained by inserting 131I in both male and female thyroid parts. (authors)

  3. Dosimetry standards

    The following leaflets are contained in this folder concerning the National Physical Laboratory's measurement services available in relation to dosimetry standards: Primary standards of X-ray exposure and X-ray irradiation facilities, X-ray dosimetry at therapy levels, Protection-level X-ray calibrations, Therapy-level gamma-ray facility, Fricke dosemeter reference service, Low-dose-rate gamma-ray facility, Penetrameter and kV meter calibration, Measurement services for radiation processing, Dichromate dosemeter reference service, Electron linear accelerator. (U.K.)

  4. Dosimetry through the Secondary Laboratory of Dosimetric Calibration of Mexico; Dosimetria a traves del Laboratorio Secundario de Calibracion Dosimetrica de Mexico

    Tovar M, V.M.; Alvarez R, J.T.; Medina O, V.P.; Vergara M, F.; Anaya M, R.; Cejudo A, J.; Salinas L, B. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2004-07-01

    In the beginnings of the sixty years an urgent necessity is presented mainly in the developing countries, of improving in important form the accuracy in the dosimetry of external faces in therapy of radiations (radiotherapy centers), mainly in the calibration of ''clinical dosemeters''. In 1976 the International Atomic Energy Agency, (IAEA), and the World Health Organization, (WHO), they carried out a mutual agreement with regard to the establishment and operation of a net of Secondary Patron Laboratories of Dosimetry, (LSCD). The necessity to establish measure patterns in the field of the dosimetry of the ionizing radiations, is necessary, to have an accuracy but high in the dosimetry of the radiation beams in therapy which is highly dependent of the dose given to the tumor of those patient with cancer. Similar levels of accuracy are required in protection measures to the radiation with an acceptable smaller accuracy, however, when the personal dosemeters are used to determine the doses received by the individuals under work conditions, such mensurations in therapy of radiations and radiological protection will have traceability through a chain of comparisons to primary or national patterns. The traceability is necessary to assure the accuracy and acceptability of the dosimetric measures, as well as, the legal and economic implications. The traceability is also necessary in the dosimetry of high dose like in the sterilization of different products. The main function of the LSCD is to provide a service in metrology of ionizing radiations, maintaining the secondary or national patterns, which have a traceability to the International System of measures, which is based for if same in the comparison of patterns in the Primary Laboratories of Dosimetry (LPD) under the auspice of the International Office of Weights and Measure (BIPM). The secondary and national patterns in the LSCD constitute in Mexico, the national patterns of the magnitudes in the

  5. 1989 neutron and gamma personnel dosimetry intercomparison study using RADCAL [Radiation Calibration Laboratory] sources

    The fourteenth Personnel Dosimetry Intercomparison Study (i.e., PDIS 14) was conducted during May 1-5, 1989. A total of 48 organizations (33 from the US and 15 from abroad) participated in PDIS 14. Participants submitted by mail a total of 1,302 neutron and gamma dosimeters for this mixed field study. The type of neutron dosimeter and the percentage of participants submitting that type are as follows: TLD-albedo (40%), direct interaction TLD (22%), track (20%), film (7%), combination (7%), and bubble detectors (4%). The type of gamma dosimeter and the percentage of participants submitting that type are as follows: TLD (84%) and film (16%). Radiation sources used in the six PDIS 14 exposures included 252Cf moderated by 15-cm D2O, 252Cf moderated by 15-cm polyethylene (gamma-enhanced with 137Cs), and 238PuBe. Neutron dose equivalents ranged from 0.44--2.63 mSv and gamma doses ranged from 0. 01-1.85 mSv. One 252Cf(D2O) exposure was performed at a 60 degree angle of incidence (most performance tests are at perpendicular incidence). The average neutron dosimeter response for this exposure was 70% of that at normal incidence. The average gamma dosimeter response was 96% of that at normal incidence. A total of 70% of individual reported neutron dosimeter measurements were within ±50% of reference values. If the 0.01 mSv data are omitted, approximately 90% of the individual reported gamma measurements were within ±50% of reference values. 33 refs., 9 figs., 27 tabs

  6. Development of dose calibrators Tandem systems and establishment of beta dosimetry in nuclear medicine

    A quality control program at Nuclear Medicine Services includes the checking of all equipment used for diagnostics and treatment, and the individual monitoring of the workers occupationally exposed to ionizing radiations. In this work the main quality control tests were performed with three dose calibrators using standard radiation sources of 57Co, 133Ba, 137Cs and 60Co. Tandem systems of dose calibrators were established and characterized using four cylindrical absorbers of different materials for an additional quality control test in Nuclear Medicine. The main utility of this new test is the possibility of impurity detection in radiopharmaceuticals, when the ratio of the measurements with different absorbers is different from that obtained at the laboratory in ideal conditions. The dosimetric characteristics of three types of CaS04:Dy + Teflon pellets were studied for an appropriate choice of the material to be used for individual monitoring of workers. The thermoluminescent detectors were irradiated using beta sources of 90Sr+90Y, 204TI, 147Pm, 153Sm and 32P. A wrist badge for beta individual monitoring was developed for workers that handle beta radiopharmaceuticals in Nuclear Medicine Services. (author)

  7. Quality assurance in radiotherapy dosimetry in China

    In 1995, the SSDL in the Laboratory of Industrial Hygiene cooperated with Beijing Cancer Hospital, Chinese Academy of Medical science joined the IAEA Co-ordinated Research Programme (NO.8769/RO). According to the requirements of the project, an External Audit Group (EAG) in China was established in 1996 with the responsibilities of operating TLD-based quality audit for radiotherapy dosimetry. Since then. The national TLD dose quality audit services have been carried out in 7 provinces in China. Besides this, the national programmes for brachytherapy and stereostatic radiosurgery (SRS) treatment dosimetry were initiated in 2001. The activity measurement intercomparison between the SSDL and some hospitals for Ir-192 HDR brachytherapy sources has been performed using a HDR well-type ionization chamber (Model HDR 1000 plus) and CDX-2000A Charge Digitizer, which were calibrated in Accredited Dosimetry Calibration Laboratory, University of Wisconsin, USA. The preliminary results indicated that the agreement between SSDL measured activity and hospital stated activity was within ±5% for more than 80% of total participants

  8. Calibration of photon and beta ray sources used in brachytherapy. Guidelines on standardized procedures at Secondary Standards Dosimetry Laboratories (SSDLs) and hospitals

    It has generally been recognized that international harmonization in radiotherapy dosimetry is essential. Consequently, the IAEA has given much effort to this, for example by publishing a number of reports in the Technical Reports Series (TRS) for external beam dosimetry, most notably TRS-277 and more recently TRS-398. Both of these reports describe in detail the steps to be taken for absorbed dose determination in water and they are often referred to as 'dosimetry protocols'. Similar to TRS-277, it is expected that TRS-398 will be adopted or used as a model by a large number of countries as their national protocol. In 1996, the IAEA established a calibration service for low dose rate (LDR) 137 Cs brachytherapy sources, which is the most widely used source for treatment of gynecological cancer. To further enhance harmonization in brachytherapy dosimetry, the IAEA published in 1999 IAEA-TECDOC-1079 entitled 'Calibration of Brachytherapy Sources. Guidelines on Standardized Procedures for the Calibration of Brachytherapy Sources at Secondary Standard Dosimetry Laboratories (SSDLs) and Hospitals'. The report was well received and was distributed in a large number of copies to the members of the IAEA/WHO network of SSDLs and to medical physicists working with brachytherapy. The present report is an update of the aforementioned TECDOC. Whereas TECDOC-1079 described methods for calibrating brachytherapy sources with photon energies at or above those of 192Ir, the current report has a wider scope in that it deals with standardization of calibration of all the most commonly used brachytherapy sources, including both photon and beta emitting sources. The latter sources have been in use for a few decades already, but their calibration methods have been unclear. Methods are also described for calibrating sources used in the rapidly growing field of cardiovascular angioplasty. In this application, irradiation of the vessel wall is done in an attempt to prevent restenosis after

  9. Radiochromic film dosimetry with flatbed scanners: A fast and accurate method for dose calibration and uniformity correction with single film exposure

    Film dosimetry is an attractive tool for dose distribution verification in intensity modulated radiotherapy (IMRT). A critical aspect of radiochromic film dosimetry is the scanner used for the readout of the film: the output needs to be calibrated in dose response and corrected for pixel value and spatial dependent nonuniformity caused by light scattering; these procedures can take a long time. A method for a fast and accurate calibration and uniformity correction for radiochromic film dosimetry is presented: a single film exposure is used to do both calibration and correction. Gafchromic EBT films were read with two flatbed charge coupled device scanners (Epson V750 and 1680Pro). The accuracy of the method is investigated with specific dose patterns and an IMRT beam. The comparisons with a two-dimensional array of ionization chambers using a 18x18 cm2 open field and an inverse pyramid dose pattern show an increment in the percentage of points which pass the gamma analysis (tolerance parameters of 3% and 3 mm), passing from 55% and 64% for the 1680Pro and V750 scanners, respectively, to 94% for both scanners for the 18x18 open field, and from 76% and 75% to 91% for the inverse pyramid pattern. Application to an IMRT beam also shows better gamma index results, passing from 88% and 86% for the two scanners, respectively, to 94% for both. The number of points and dose range considered for correction and calibration appears to be appropriate for use in IMRT verification. The method showed to be fast and to correct properly the nonuniformity and has been adopted for routine clinical IMRT dose verification

  10. Comparison of two standard dosimetry protocols for output calibration of 60Co teletherapy machines

    Two protocols for output calibration of 60Co teletherapy machines were studied in two steps. In the first step, two methods for timer error determination were studied both in air and in water: the two-exposure method with the short exposure time ranging in value form ts=0.1tL to ts=0.7tL, where tL is the long exposure time; and the single/multiple exposure method with the number of exposures ranging from n=2 to n=9. The results showed better precision for the two-exposure method with smaller ratios of ts to tL and for the single/multiple exposure method with the greater n, and also showed better precision for in-air than in-water measurements in both protocols. A comparison was made between the two-exposure protocol with ts=0.2tL, 0.3tL and 0.5tL and the single/multiple exposure protocol with n=6. In-air measurements showed the best results with ts=0.2tL in terms of both precision and decay constants estimated from the regression of exposure rate against time. In the second step, the protocol with n=6 was used in comparing the output value measured in air with that measured in water. The dose rates at 5 cm depth in water determined by these two methods of measurement were comparable to within ±0.5%. (author). 8 refs, 3 figs, 2 tabs

  11. Accredited Birth Centers

    ... 717-933-9743 Accredited since January 2016 100 Bright Eyes Midwifery and Wild Rivers Women's Health Accredited ... Birthing Center-Cedar Park Accredited 1130 Cottonwood Creek Trail Building D Suite 2 Cedar Park, TX 78613 ...

  12. Fourth conference on radiation protection and dosimetry: Proceedings, program, and abstracts

    Casson, W.H.; Thein, C.M.; Bogard, J.S. [eds.

    1994-10-01

    This Conference is the fourth in a series of conferences organized by staff members of Oak Ridge National Laboratory in an effort to improve communication in the field of radiation protection and dosimetry. Scientists, regulators, managers, professionals, technologists, and vendors from the United States and countries around the world have taken advantage of this opportunity to meet with their contemporaries and peers in order to exchange information and ideas. The program includes over 100 papers in 9 sessions, plus an additional session for works in progress. Papers are presented in external dosimetry, internal dosimetry, radiation protection programs and assessments, developments in instrumentation and materials, environmental and medical applications, and on topics related to standards, accreditation, and calibration. Individual papers are indexed separately on EDB.

  13. (Re)implantation of quality system of LCR (Laboratory for Radiation Sciences) for accreditation in the standard ABNT NBR ISO/IEC 17025:2005; (Re)implantacao do sistema da qualidade do LCR para acreditacao na ABNT NBR ISO/IEC 17025:2005

    Leite, Sandro P., E-mail: leite_sp@ig.com.br [Rede Sibratec, Sao Paulo, SP (Brazil); Fernandes, Elisabeth O.; David, Mariano G.; Pires, Evandro J.; Alves, Carlos F.E.; Almeida, Carlos E. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil)

    2014-07-01

    This paper presents preparing procedure of the metrology laboratory (LABMETRO), which belongs Laboratorio de Ciencias Radiologicas of Rio de Janeiro , for postulating accreditation of its services metrology to INMETRO. This process, supported by the Technological Services Network SIBRATEC/FINEP for Radiation Protection and Dosimetry Technological Services, had as one of its aims to avoid possible technical barriers to the purchase services in the area of ionizing radiation laboratories. Accreditation will also enable the integration of services such laboratories in Brazilian Calibration Network (RBC). (author)

  14. Bilateral comparison 2012 between calibration laboratories dosimetry spaniards for qualities ISO: S-Cs and S-Co

    This paper describes the Protocol and the results of the comparison bilateral organized during 2012, between two Spanish calibration laboratories. The main objective of the comparison was to contribute to verification and documentation of the consistency of calibration services offered at national level, with regard to the metrological traceability of calibrations and dose levels of protection assignments radiation to gamma radiation. (Author)

  15. Measurement assurance in dosimetry

    The uses of radiation in medicine and industry are today wide in scope and diversity and there is a need for reliable dosimetry in most applications. In particular, high accuracy in dosimetry is required in the therapeutic use of radiation. Consequently, calibration procedures for radiotherapy generally meet also the accuracy requirements for applications in other fields, such as diagnostic radiology, radiation protection and industrial radiation processing. The emphasis at this symposium was therefore mainly or radiotherapy dosimetry, but the meeting also included one session devoted to dosimetry in diagnostic radiology. Refs, fig and tabs

  16. Dosimetry of ionizing radiation

    The publication deals with a major field of ionizing radiation dosimetry, viz., integrating dosimetric methods, which are the basic means of operative dose determination. It is divided into the following sections: physical and chemical effects of ionizing radiation; integrating dosimetric methods for low radiation doses (film dosimetry, nuclear emulsions, thermoluminescence, radiophotoluminescence, solid-state track detectors, integrating ionization dosemeters); dosimetry of high ionizing radiation doses (chemical dosimetric methods, dosemeters based on the coloring effect, activation detectors); additional methods applicable to integrating dosimetry (exoelectron emission, electron spin resonance, lyoluminescence, etc.); and calibration techniques for dosimetric instrumentation. (Z.S.). 422 refs

  17. DRDC Ottawa working standard for biological dosimetry

    Segura, T.M.; Prud' homme-Lalonde, L. [Defence Research and Development Canada, Ottawa, Ontario (Canada); Thorleifson, E. [Health Canada, Gatineau, Quebec (Canada); Lachapelle, S.; Mullins, D. [JERA Consulting (Canada); Qutob, S. [Health Canada, Gatineau, Quebec (Canada); Wilkinson, D.

    2005-07-15

    This Standard provides quality assurance, quality control, and evaluation of the performance criteria for the purpose of accreditation of the Radiation Biology laboratory at Defence Research and Development Canada - Ottawa (DRDC Ottawa) using biological dosimetry to predict radiation exposure doses. The International Standard (ISO 19238) and the International Atomic Energy Association (IAEA) Technical Report Series No. 405 are used as guiding documents in preparation of this working document specific to the DRDC Ottawa Radiation Biology Laboratory. This Standard addresses: 1. The confidentiality of personal information, for the customer and the service laboratory; 2. The laboratory safety requirements; 3. The calibration sources and calibration dose ranges useful for establishing the reference dose-effect curves allowing the dose estimation from chromosome aberration frequency, and the minimum detection levels; 4. Transportation criteria for shipping of test samples to the laboratory; 5. Preparation of samples for analysis; 6. The scoring procedure for unstable chromosome aberrations used for biological dosimetry; 7. The criteria for converting a measured aberration frequency into an estimate of absorbed dose; 8. The reporting of results; 9. The quality assurance and quality control plan for the laboratory; and 10. Informative annexes containing examples of a questionnaire, instructions for customers, a data sheet for recording aberrations, a sample report and other supportive documents. (author)

  18. DRDC Ottawa working standard for biological dosimetry

    This Standard provides quality assurance, quality control, and evaluation of the performance criteria for the purpose of accreditation of the Radiation Biology laboratory at Defence Research and Development Canada - Ottawa (DRDC Ottawa) using biological dosimetry to predict radiation exposure doses. The International Standard (ISO 19238) and the International Atomic Energy Association (IAEA) Technical Report Series No. 405 are used as guiding documents in preparation of this working document specific to the DRDC Ottawa Radiation Biology Laboratory. This Standard addresses: 1. The confidentiality of personal information, for the customer and the service laboratory; 2. The laboratory safety requirements; 3. The calibration sources and calibration dose ranges useful for establishing the reference dose-effect curves allowing the dose estimation from chromosome aberration frequency, and the minimum detection levels; 4. Transportation criteria for shipping of test samples to the laboratory; 5. Preparation of samples for analysis; 6. The scoring procedure for unstable chromosome aberrations used for biological dosimetry; 7. The criteria for converting a measured aberration frequency into an estimate of absorbed dose; 8. The reporting of results; 9. The quality assurance and quality control plan for the laboratory; and 10. Informative annexes containing examples of a questionnaire, instructions for customers, a data sheet for recording aberrations, a sample report and other supportive documents. (author)

  19. Quality assurance in personal dosimetry of external radiation: present situation and future needs

    Whole body personal dosimetry is well established for the individual monitoring of radiation workers. High quality radiation dosimetry is essential for workers who rely upon personal dosemeters to record the amount of radiation to which they are exposed. The mandate has been given to the Personal Dosimetry, (secondary standard dosimetry laboratories) S.S.D.L., (Malaysian institute for nuclear energy research) M.I.N.T. to assure the individual monitoring for radiation workers in Malaysia. In 2005, the S.S.D.L;-M.I.N.T. supply, process and read out of personal dosemeters of nearly 13,000 dosimeters monthly, whereby. 12,000 are films and 1,000 are T.L.D.s. The objective of individual monitoring is not limited to the measurement of doses delivered to individuals, but it should demonstrate that limits of exposure have not been exceeded and that working conditions have not unexpectedly deteriorated. Dosimetry measurements are an important component of radiation protection programs and must be of high quality. The exposure of workers to radiation must be controlled and monitored in order to comply with regulatory requirements. S.S.D.L.-M.I.N.T; demonstrates that its performance is at an acceptable level by implementing overall system performance, as evidenced by the ISO 9001 certification of the Personal Dosimetry Service in 2002 and ISO/I.E.C. 17025 accreditation to the calibration laboratory in 2004. The certification and accreditation processes achieved the goal by formalizing the recognition of satisfactory performance, and providing evidence of this performance. Overall performances are assessed, personnel operating the system will be trained and are well qualified and all actions will be documented. The paper describes the overview of the Q.M.S. carried out at the S.S. D.L.-M.I.N.T.. During the implementation of Q.M.S. a few areas has been identified for future consideration. These include performance specification and type testing of dosemeters, which provide a

  20. Evaluation on the effect of dosimetry using a depth of calibration point or a depth of temporary dose maximum in high energy electron beams

    The Japan Society of Medical Physics (JSMP) has published a new dosimetry protocol ''JSMP-01'' for the calibration of radiotherapy beams. This protocol provides a new definition of the calibration point (depth) in order to obtain the absorbed dose at a reference point (Dr) by the calculation in high energy electron beams. This study evaluated the difference in the absorbed dose at the depth dose maximum (Ddmax) and Dr calculated from the absorbed dose at the calibration point. Further, the difference in the absorbed dose (Ddmax) at ''measured maximum depth (dmax)'' was evaluated using ''temporary maximum depth (dmax*)''. In the experiment at a depth interval of 0.1 g cm2, no difference was observed between Ddmax and Dr. However, in the experiment at a depth interval of 0.3 g cm-2 the differences between Ddmax and Dr increased to 6.4% and 5.2% at 4 MeV and 6 MeV, respectively. Subsequently, at all energy levels the difference between Ddmax and Dr of all energy was more than 3% at a depth interval of 0.4 g cm-2. The differences between Ddmax and Ddmax* were 2.68% and 4.50% at 6 MeV and 9 MeV, respectively, for this depth interval. (author)

  1. Comparison of radiotherapy dosimetry for 3D-CRT, IMRT, and SBRT based on electron density calibration

    Kartutik, K.; Wibowo, W. E.; Pawiro, S. A.

    2016-03-01

    Accurate calculation of dose distribution affected by inhomogeneity tissue is required in radiotherapy planning. This study was performed to determine the ratio between radiotherapy planning using 3D-CRT, IMRT, and SBRT based on a calibrated curve of CT-number in the lung for different target's shape in 3D-CRT, IMRT, and spinal cord for SBRT. Calibration curves of CT-number were generated under measurement basis and introduced into TPS, then planning was performed for 3D-CRT, IMRT, and SBRT with 7, and 15 radiation fields. Afterwards, planning evaluation was performed by comparing the DVH curve, HI, and CI. 3D-CRT and IMRT produced the lowest HI at calibration curve of CIRS 002LFC with the value 0.24 and 10. Whereas SBRT produced the lowest HI on a linear calibration curve with a value of 0.361. The highest CI in IMRT and SBRT technique achieved using a linear calibration curve was 0.97 and 1.77 respectively. For 3D-CRT, the highest CI was obtained by using calibration curve of CIRS 062M with the value of 0.45. From the results of CI and HI, it is concluded that the calibration curve of CT-number does not significantly differ with Schneider's calibrated curve, and inverse planning gives a better result than forward planning.

  2. Estimation of absorbed dose in clinical radiotherapy linear accelerator beams: effect of ion chamber calibration and long-term stability

    The measured dose in water at reference point in phantom is a primary parameter for planning the treatment monitor units (MU); both in conventional and intensity modulated/image guided treatments. Traceability of dose accuracy therefore still depends mainly on the calibration factor of the ion chamber/dosimeter provided by the accredited Secondary Standard Dosimetry Laboratories (SSDLs), under International Atomic Energy Agency (IAEA) network of laboratories. The data related to Nd,water calibrations, thermoluminescent dosimetry (TLD) postal dose validation, inter-comparison of different dosimeter/electrometers, and validity of Nd,water calibrations obtained from different calibration laboratories were analyzed to find out the extent of accuracy achievable. Nd,w factors in Gray/Coulomb calibrated at IBA, GmBH, Germany showed a mean variation of about 0.2% increase per year in three Farmer chambers, in three subsequent calibrations. Another ion chamber calibrated in different accredited laboratory (PTW, Germany) showed consistent Nd,w for 9 years period. The Strontium-90 beta check source response indicated long-term stability of the ion chambers within 1% for three chambers. Results of IAEA postal TL 'dose intercomparison' for three photon beams, 6 MV (two) and 15 MV (one), agreed well within our reported doses, with mean deviation of 0.03% (SD 0.87%) (n = 9). All the chamber/electrometer calibrated by a single SSDL realized absorbed doses in water within 0.13% standard deviations. However, about 1-2% differences in absorbed dose estimates observed when dosimeters calibrated from different calibration laboratories are compared in solid phantoms. Our data therefore imply that the dosimetry level maintained for clinical use of linear accelerator photon beams are within recommended levels of accuracy and uncertainities are within reported values. (author)

  3. SU-E-T-433: Calibration Accuracy in Mailed High-Resolution 3D Dosimetry Service for SRS/SBRT QA

    Purpose: SRS/SBRT combines hypofractionation with excellent dose distributions. However, extremely steep gradients across the target along with dose escalation, if not administered accurately, may lead to serious complications, recurrences, or even fatalities. Existing commercial QA products either lack adequate spatial resolution or the 3D aspect. By contrast, the new CrystalBall™ mailed high-resolution 3D dosimetry service removes the above limitations while reducing the overall workload on medical physics staff. The exposed dosimeters, which change optical density in proportion to local dose, are sent back to the manufacturer (MGS Research Inc., Madison, CT) for sub-millimeter-resolution laser-CT scanning and QA data analysis. QA report is returned electronically within 24 hours. The purpose of this study was to evaluate the dose calibration accuracy in this system. Methods: Two spherical CrystalBall™ polymer gel dosimeters from the same batch, 166 mm diameter, with embedded 3D image registration markers, were mounted in a special phantom designed for reproducible positioning. For full end to end testing, the optical guidance array was mounted onto the phantom and a CT was taken. Two separate Rapid Arc SRS plans were designed. Varian Medical Systems optical guidance system was used to position the phantom and the SRS treatment plans were delivered to the two spheres on Varian's Trilogy Accelerator. Exposed dosimeters were mailed back to the manufacturer for laser CT scanning and analysis. Results: For each plan, 3D gamma passing rate was 100% for 2%/2mm distance-to-agreement criteria above 50% isodose level. The two calibration curves, generated using volumetric dose and optical density data, showed excellent mutual agreement (max difference 2.2%, median difference 0.75%). Conclusion: The clinical utility of new CrystalBall™ mailed QA service for SRS/SBRT and high accuracy of dose calibration have been validated. The workflow associated with the use

  4. Accreditation: The American Experience.

    Adelman, Clem; Silver, Harold

    The report presents the findings of an investigation into the trends and issues concerning accreditation of professionals and institutions of higher education in the United States. In late 1988 and early 1989, the study examined the accreditation of courses in nursing, engineering, and teacher education, and the accreditation of institutions in…

  5. NVLAP calibration laboratory program

    Cigler, J.L.

    1993-12-31

    This paper presents an overview of the progress up to April 1993 in the development of the Calibration Laboratories Accreditation Program within the framework of the National Voluntary Laboratory Accreditation Program (NVLAP) at the National Institute of Standards and Technology (NIST).

  6. Absolute calibration of the Gamma Knife{sup ®} Perfexion™ and delivered dose verification using EPR/alanine dosimetry

    Hornbeck, Amaury, E-mail: amauryhornbeck@gmail.com, E-mail: tristan.garcia@cea.fr; Garcia, Tristan, E-mail: amauryhornbeck@gmail.com, E-mail: tristan.garcia@cea.fr [CEA, LIST, Laboratoire National Henri Becquerel, 91191 Gif-sur-Yvette Cedex (France); Cuttat, Marguerite; Jenny, Catherine [Radiotherapy Department, Medical Physics Unit, University Hospital Pitié-Salpêtrière, 75013 Paris (France)

    2014-06-15

    Purpose: Elekta Leksell Gamma Knife{sup ®} (LGK) is a radiotherapy beam machine whose features are not compliant with the international calibration protocols for radiotherapy. In this scope, the Laboratoire National Henri Becquerel and the Pitié-Salpêtrière Hospital decided to conceive a new LKG dose calibration method and to compare it with the currently used one. Furthermore, the accuracy of the dose delivered by the LGK machine was checked using an “end-to-end” test. This study also aims to compare doses delivered by the two latest software versions of the Gammaplan treatment planning system (TPS). Methods: The dosimetric method chosen is the electron paramagnetic resonance (EPR) of alanine. Dose rate (calibration) verification was done without TPS using a spherical phantom. Absolute calibration was done with factors calculated by Monte Carlo simulation (MCNP-X). For “end-to-end” test, irradiations in an anthropomorphic head phantom, close to real treatment conditions, are done using the TPS in order to verify the delivered dose. Results: The comparison of the currently used calibration method with the new one revealed a deviation of +0.8% between the dose rates measured by ion chamber and EPR/alanine. For simple fields configuration (less than 16 mm diameter), the “end-to-end” tests showed out average deviations of −1.7% and −0.9% between the measured dose and the calculated dose by Gammaplan v9 and v10, respectively. Conclusions: This paper shows there is a good agreement between the new calibration method and the currently used one. There is also a good agreement between the calculated and delivered doses especially for Gammaplan v10.

  7. Characterization of calibration curves and energy dependence GafChromicTM XR-QA2 model based radiochromic film dosimetry system

    Purpose: The authors investigated the energy response of XR-QA2 GafChromicTM film over a broad energy range used in diagnostic radiology examinations. The authors also made an assessment of the most suitable functions for both reference and relative dose measurements. Methods: Pieces of XR-QA2 film were irradiated to nine different values of air kerma in air, following reference calibration of a number of beam qualities ranging in HVLs from 0.16 to 8.25 mm Al, which corresponds to effective energy range from 12.7 keV to 56.3 keV. For each beam quality, the authors tested three functional forms (rational, linear exponential, and power) to assess the most suitable function by fitting the delivered air kerma in air as a function of film response in terms of reflectance change. The authors also introduced and tested a new parameterχ = netΔR·em netΔR that linearizes the inherently nonlinear response of the film. Results: The authors have found that in the energy range investigated, the response of the XR-QA2 based radiochromic film dosimetry system ranges from 0.222 to 0.420 in terms of netΔR at Kairair = 8 cGy. For beam qualities commonly used in CT scanners (4.03–8.25 mm Al), the variation in film response (netΔR at Kairair = 8 cGy) amounts to ± 5%, while variation in Kairair amounts to ± 14%. Conclusions: Results of our investigation revealed that the use of XR-QA2 GafChromicTM film is accompanied by a rather pronounced energy dependent response for beam qualities used for x-ray based diagnostic imaging purposes. The authors also found that the most appropriate function for the reference radiochromic film dosimetry would be the power function, while for the relative dosimetry one may use the exponential response function that can be easily linearized

  8. Testing and linearity calibration of films of phenol compounds exposed to thermal neutron field for EPR dosimetry.

    Gallo, S; Panzeca, S; Longo, A; Altieri, S; Bentivoglio, A; Dondi, D; Marconi, R P; Protti, N; Zeffiro, A; Marrale, M

    2015-12-01

    This paper reports the preliminary results obtained by Electron Paramagnetic Resonance (EPR) measurements on films of IRGANOX® 1076 phenols with and without low content (5% by weight) of gadolinium oxide (Gd2O3) exposed in the thermal column of the Triga Mark II reactor of LENA (Laboratorio Energia Nucleare Applicata) of Pavia (Italy). Thanks to their size, the phenolic films here presented are good devices for the dosimetry of beams with high dose gradient and which require accurate knowledge of the precise dose delivered. The dependence of EPR signal as function of neutron dose was investigated in the fluence range between 10(11) cm(-2) and 10(14) cm(-2). Linearity of EPR response was found and the signal was compared with that of commercial alanine films. Our analysis showed that gadolinium oxide (5% by weight) can enhance the thermal neutron sensitivity more than 18 times. Irradiated dosimetric films of phenolic compound exhibited EPR signal fading of about 4% after 10 days from irradiation. PMID:26242561

  9. Proceedings of the second conference on radiation protection and dosimetry

    The Second Conference on Radiation Protection and Dosimetry was held during October 31--November 3, 1988, at the Holiday Inn, Crowne Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To facilitate meeting these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical sessions included external dosimetry, internal dosimetry, calibration, standards and regulations, instrumentation, accreditation and test programs, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. This document provides a summary of the conference technical program and a partial collection of full papers for the oral presentations in order of delivery. Individual papers were processed separately for the data base

  10. Proceedings of the second conference on radiation protection and dosimetry

    Swaja, R. E.; Sims, C. S. [eds.

    1988-11-01

    The Second Conference on Radiation Protection and Dosimetry was held during October 31--November 3, 1988, at the Holiday Inn, Crowne Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To facilitate meeting these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical sessions included external dosimetry, internal dosimetry, calibration, standards and regulations, instrumentation, accreditation and test programs, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. This document provides a summary of the conference technical program and a partial collection of full papers for the oral presentations in order of delivery. Individual papers were processed separately for the data base.

  11. Electromedical devices test laboratories accreditation

    Murad, C.; Rubio, D.; Ponce, S.; Álvarez Abri, A.; Terrón, A.; Vicencio, D.; Fascioli, E.

    2007-11-01

    In the last years, the technology and equipment at hospitals have been increase in a great way as the risks of their implementation. Safety in medical equipment must be considered an important issue to protect patients and their users. For this reason, test and calibrations laboratories must verify the correct performance of this kind of devices under national and international standards. Is an essential mission for laboratories to develop their measurement activities taking into account a quality management system. In this article, we intend to transmit our experience working to achieve an accredited Test Laboratories for medical devices in National technological University.

  12. Preliminary measurements of the establishment of a quality control programme for the activimeter calibration reference system

    The nuclear medicine techniques efficiency and safety depends on, beside other factors, a quality control programme, mainly regards to the nuclides activimeter utilization. The Calibration Laboratory of IPEN uses as a work standard, a tertiary standard system Capintec, calibrated at the Accredited Dosimetry Calibration Laboratory of the Medical radiation Research Center - University of Wisconsin. In this work, as preliminary measurements to establish a quality control programme for the activimeter calibration procedures, initially the repeatability and reproducibility (long term stability) tests were performed using a sealed check source of 133Ba. Later on, to complete this quality control programme other check sources (137Cs, 57Co, 60Co) will be used to perform the same tests. A series of 80 experiments of 10 measurements each has been carried out. The reference system showed a good behaviour to the repeatability test, considering the tolerance limits of 5%. The percent deviations of all tested sources in the activity measurements were lower 1% to 133Ba. (author)

  13. Sixth symposium on neutron dosimetry

    This booklet contains all abstracts of papers presented in 13 sessions. Main topics: Cross sections and Kerma factors; analytical radiobiology; detectors for personnel monitoring; secondary charged particles and microdosimetric basis of q-value for neutrons; personnel dosimetry; concepts for radiation protection; ambient monitoring; TEPC and ion chambers in radiation protection; beam dosimetry; track detectors (CR-39); dosimetry at biomedical irradiation facilities; health physics at therapy facilities; calibration for radiation protection; devices for beam dosimetry (TLD and miscellaneous); therapy and biomedical irradiation facilities; treatment planning. (HP)

  14. Ion chamber absorbed dose calibration coefficients, ND,w, measured at ADCLs: Distribution analysis and stability

    Purpose: To analyze absorbed dose calibration coefficients, ND,w, measured at accredited dosimetry calibration laboratories (ADCLs) for client ionization chambers to study (i) variability among ND,w coefficients for chambers of the same type calibrated at each ADCL to investigate ion chamber volume fluctuations and chamber manufacturing tolerances; (ii) equivalency of ion chamber calibration coefficients measured at different ADCLs by intercomparing ND,w coefficients for chambers of the same type; and (iii) the long-term stability of ND,w coefficients for different chamber types by investigating repeated chamber calibrations. Methods: Large samples of ND,w coefficients for several chamber types measured over the time period between 1998 and 2014 were obtained from the three ADCLs operating in the United States. These are analyzed using various graphical and numerical statistical tests for the four chamber types with the largest samples of calibration coefficients to investigate (i) and (ii) above. Ratios of calibration coefficients for the same chamber, typically obtained two years apart, are calculated to investigate (iii) above and chambers with standard deviations of old/new ratios less than 0.3% meet stability requirements for accurate reference dosimetry recommended in dosimetry protocols. Results: It is found that ND,w coefficients for a given chamber type compared among different ADCLs may arise from differing probability distributions potentially due to slight differences in calibration procedures and/or the transfer of the primary standard. However, average ND,w coefficients from different ADCLs for given chamber types are very close with percent differences generally less than 0.2% for Farmer-type chambers and are well within reported uncertainties. Conclusions: The close agreement among calibrations performed at different ADCLs reaffirms the Calibration Laboratory Accreditation Subcommittee process of ensuring ADCL conformance with National Institute of

  15. Secondary standards dosimetry laboratories

    The Secondary Standards Dosimetry Laboratory (SSDL) is part of an international network of dosimetry laboratories established by the IAEA and WHO. The network services maintain the consistency and accuracy of the therapeutic dose by exercising a national and international intercomparison program as well as providing calibration services to the end users, mainly radiotherapy departments in hospitals. The SSDL's are designated by national laboratories (such as Primary Standards Dosimetry Laboratories, PSDL's) to provide national and international absorbed dose traceability for users in that country. The advantage of the SSDL is that the absorbed dose measurements are consistent among the stakeholder countries.The Physics and Safety divisions have recently re-established an SSDL at ANSTO. The SSDL utilises a collimated cobalt-60 source of activity 170 TBq and dose rate of SmGy/sec at 1 metre (within ±2%), and provides a service to calibrate therapy level thimble ionisation chambers and electrometers

  16. Training Accreditation Program

    The Training Accreditation Program establishes the objectives and criteria against which DOE nuclear facility training is evaluated to determine its readiness for accreditation. Training programs are evaluated against the accreditation objectives and criteria by facility personnel during the initial self-evaluation process. From this self-evaluation, action plans are made by the contractor to address the scope of work necessary in order to upgrade any deficiencies noted. This scope of work must be formally documented in the Training Program Accreditation Plan. When reviewed and approved by the responsible Head of the Field Organization and cognizant Program Secretarial Office, EH-1 concurrence is obtained. This plan then becomes the document which guides accreditation efforts for the contractor

  17. Activities developed by the biological dosimetry laboratory of the Autoridad Regulatoria Nuclear - ARN of Argentina

    Biological dosimetry (DB) allows to estimate doses absorbed in individuals exposed to ionizing radiation through the quantification of stable and unstable chromosome aberrations (SCA and UCA). The frequency of these aberrations is referred to a calibration dose response curve (in vitro) to determine the doses of the individual to the whole body. The DB is a necessary support for programs of national radiation protection and response systems in nuclear or radiological emergencies in the event of accidental or incidental, single overexposure or large scale. In this context the Laboratory of Dosimetry Biological (LDB) of the Authority Regulatory Nuclear (ARN) Argentina develops and applies different dosimeters cytogenetic from four decades ago. These dosimeters provide a fact more within the whole of the information necessary for an accidental, complementing the physical and clinical dosimetry exposure assessment. The most widely used in the DB biodosimetric method is the quantification of SCA (dicentrics and rings Central) from a sample of venous blood. The LDB is accredited for the trial, under rules IRAM 301: 2005 (ISO / IEC 17025: 2005) and ISO 19238:2004. Test applies to the immediate dosimetry evaluation of acute exposures, all or a large part of the body in the range 0,1-5 Gy. In this context the LDB is part of the Latin American network of DB (LBDNet), BioDoseNet-who and response system in radiological emergencies and nuclear IAEA-RANET, being enabled to summon the LBDNet if necessary

  18. Accreditation of nuclear engineering programs

    The American Nuclear Society (ANS) Professional Development and Accreditation Committee (PDAC) has the responsibility for accreditation of engineering and technology programs for nuclear and similarly named programs. This committee provides society liaison with the Accreditation Board for Engineering and Technology (ABET), is responsible for the appointment and training of accreditation visitors, nomination of members for the ABET Board and Accreditation Commissions, and review of the criteria for accreditation of nuclear-related programs. The committee is composed of 21 members representing academia and industry. The ABET consists of 19 participating bodies, primarily professional societies, and 4 affiliate bodies. Representation on ABET is determined by the size of the professional society and the number of programs accredited. The ANS, as a participating body, has one member on the ABET board, two members on the Engineering Accreditation Commission, and one on the Technology Accreditation Commission. The ABET board sets ABET policy and the commissions are responsible for accreditation visits

  19. Tales of Accreditation Woe.

    Dickmeyer, Nathan

    2002-01-01

    Offers cautionary tales depicting how an "Enron mentality" infiltrated three universities and jeopardized their accreditation status. The schools were guilty, respectively, of bad bookkeeping, lack of strategy and stable leadership, and loss of academic integrity by selling degrees. (EV)

  20. The Next Accreditation System.

    Kirk, Lynne M

    2016-02-01

    The Accreditation Council for Graduate Medical Education has implemented a new accreditation system for graduate medical education in the United States. This system, called the Next Accreditation System, focuses on more continuous monitoring of the outcomes of residency training, and for high-quality programs, less on the detailed processes of that training. This allows programs to innovate to best meet the needs of their trainees and communities. This new system also reviews the clinical learning environment at each institution sponsoring graduate medical education, focusing on professionalism, trainee supervision, duty hour and fatigue management, care transitions, and integration of residents into patient safety and health care quality. This Next Accreditation System is too new to fully assess its outcomes in better preparing residents for medical practice. Assessments of its early implementation, however, suggest we can expect such outcomes in the near future. PMID:26859375

  1. Dosimetry Service

    2004-01-01

    We wish to remind the people who are invited to the dosimetry service to exchange the new CERN dosimeter that the hours are from Monday to Friday 8.30 to 11.00 and 14.00 to 16.00. http://service-rp-dosimetry.web.cern.ch/service-rp-dosimetry/

  2. Accreditation of laboratories in the field of radiation protection

    This paper gives a review of requirements and procedures for the accreditation of test and calibration laboratories in the field of radiation protection, paying particular attention to Croatia. General requirements to be met by a testing or calibration laboratory to be accredited are described in the standard HRN EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories. The quality of a radiation protection programme can only be as good as the quality of the measurements made to support it. Measurement quality can be assured by participation in measurement assurance programmes that evaluate the appropriateness of procedures, facilities, and equipment and include periodic checks to assure adequate performance. These also include internal consistency checks, proficiency tests, intercomparisons and site visits by technical experts to review operations. In Croatia, laboratories are yet to be accredited in the field of radiation protection. However, harmonisation of technical legislation with the EU legal system will require some changes in laws and regulations in the field of radiation protection, including the ones dealing with the notification of testing laboratories and connected procedures. Regarding the notification procedures for testing laboratories in Croatia, in the regulated area, the existing accreditation infrastructure, i.e. Croatian Accreditation Agency is ready for its implementation, as it has already established and further developed a consistent accreditation system, compatible with international requirements and procedures.(author)

  3. Dosimetry Service

    2006-01-01

    Cern Staff and Users can now consult their dose records for an individual or an organizational unit with HRT. Please see more information on our web page: http://cern.ch/rp-dosimetry Dosimetry Service is open every morning from 8.30 - 12.00. Closed in the afternoons. We would like to remind you that dosimeters cannot be sent to customers by internal mail. Short-term dosimeters (VCT's) must always be returned to the Service after the use and must not be left on the racks in the experimental areas or in the secretariats. Dosimetry Service Tel. 7 2155 Dosimetry.service@cern.ch http://cern.ch/rp-dosimetry

  4. Quality control at the Regional Centre of Nuclear Sciences chemical dosimetry laboratory

    Souza, Vivianne L.B. de; Melo, Roberto T. de; Silva, Danubia B. da; Pedroza, Eryka H.; Rodrigues, Kelia R.G.; Cunha, Manuela S. da; Figueiredo, Marcela D.C. de [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Oliveira, Aristides, E-mail: vlsouza@cnen.gov.b, E-mail: rtmelo@cnen.gov.b [Hospital de Cancer de Pernambuco, Recife, PE (Brazil)

    2011-07-01

    Standards for accreditation of laboratories as in ISO 9001 in section: 4.11 require inspection, measuring and equipment testing; likewise, IEC 17025: 2005 in section: 5.5.2 requires the equipment to be calibrated or verified before being put into use. In our laboratory, quality control is often accomplished by standards set done by the laboratory scientists themselves; however, at present, Hellma secondary calibration standards (4026 - Holmium oxide - Filters: F0, F2, F3, F4 and filter didymium - F7) have been used in order to verify if errors in the laboratory have been close to the 1-2% margin. Control graphs were made by using the results of synthetically prepared standards and standardized spectral calibration certificates. The set of secondary calibration standards permits to check the accuracy of the spectrophotometers used in research for both the absorbance in the visible spectrum (at 440, 465, 546, 590 and 635 nm wavelengths) and for the wavelengths (270, 280, 300, 320 nm) of the ultraviolet light. Filters (F0, F2, F3, F4 and F7) are stable and do not suffer the influence of temperature (the influence is negligible), the F0 filter was being used as a blank. The purpose is to verify whether the spectrometer needs adjustments, an important procedure to check absorbance stability, baseline flatness, slit width accuracy and stray radiation. The calibration tests are performed annually in our laboratory and recalibration of Hellma secondary standards is recommended every two years. The results show that the Chemical Dosimetry Laboratory in CRCN has a calibrated spectrophotometer and their synthetic standards for Fricke dosimetry could be used as an alternative method for testing the proficiency and competence of calibration laboratories in accordance with the regulations and standards. (author)

  5. Evaluation of uncertainty in dosimetry of irradiator system

    This paper describes the study of uncertainties in the estimates of dosimetry irradiator system STS 0B85 of LCI IPEN/CNEN-SP. This study is relevant for determination of best measurement capability when the laboratory performs routine calibrations of measuring radiation next the optimal measures designed to radioprotection. It is also a requirement for obtaining the accreditation of the laboratory by the INMETRO. For this dosimetry was used a reference system of the laboratory composed of a electrometer and a spherical ionization chamber of 1 liter. Measurements were made at five distances selected so to include the whole range of the optical bench tests and using three attenuators filters so as to extend the measurement capability. The magnitude used for evaluation was the rate of air kerma for 137Cs and 60Co beams. Were carried out four series of measurements. It was verified the inverse square law to these series and their sets of uncertainty. Unfiltered, with one and two filters series showed good agreement with the inverse square low and the maximum uncertainty obtained was approximately 1.7%. In series with all the filters was a major deviation of the inverse square law and wide increase in uncertainty to measurements at the end of the optical bench

  6. Neutron dosimetry

    A neutron irradiation facility was designed and built in order to establish a procedure for calibrating neutron monitors and dosemeters. A 185 GBq 241 Am Be source of known is used as a reference source. The irradiation facility using this source in the air provides neutron dose rates between 9 nSv s-1 and 0,5 μSv s-1. A calibrated 50 nSv s-1 thermal neutron field is obtained by using a specially designed paraffin block in conjunction with the 241 Am Be source. A Bonner multisphere spectrometer was calibrated, using a procedure based on three methods proposed by international standards. The unfold 241 Am Be neutron spectrum was determined from the Bonner spheres data and resulted in a good agreement with expected values for fluence rate, dose rate and mean energy. A dosimetric system based on the electrochemical etching of CR-39 was developed for personal dosimetry. The dosemeter badge using a (n,α) converter, the etching chamber and high frequency power supply were designed and built specially for this project. The electrochemical etching (ECE) parameters used were: a 6N KOH solution, 59 deg C, 20 kVpp cm-1, 2,0 kHz, 3 hours of ECE for thermal and intermediate neutrons and 6 hours for fast neutrons. The calibration factors for thermal, intermediate and fast neutrons were determined for this personal dosemeter. The sensitivities determined for the developed dosimetric system were (1,46± 0,09) 104 tracks cm-2 mSv-1 for thermal neutrons, (9±3) 102 tracks cm-2 mSV-1 for intermediate neutrons and (26±4) tracks cm-2 mSv-1 for fast neutrons. The lower and upper limits of detection were respectively 0,002 mSv and 0,6 mSv for thermal neutrons, 0,04 mSv and 8 mSv for intermediate neutrons and 1 mSv and 12 mSv for fast neutrons. In view of the 1990's ICRP recommendations, it is possible to conclude that the personal dosemeter described in this work is sufficiently sensitive to thermal and intermediate neutrons but fast neutron monitoring ar radiological protection level

  7. [Accreditation in health care].

    Fügedi, Gergely; Lám, Judit; Belicza, Éva

    2016-01-24

    Besides the rapid development of healing procedures and healthcare, efficiency of care, institutional performance and safe treatment are receiving more and more attention in the 21st century. Accreditation, a scientifically proven tool for improving patient safety, has been used effectively in healthcare for nearly a hundred years, but only started to spread worldwide since the 1990s. The support and active participation of medical staff are determining factors in operating and getting accross the nationally developed, upcoming Hungarian accreditation system. However, this active assistance cannot be expected without the participants' understanding of the basic goals and features of the system. The presence of the ISO certification in Hungary, well-known by healthcare professionals, further complicates the understanding and orientation among quality management and improvement systems. This paper aims to provide an overview of the history, goals, function and importance of healthcare accreditation, and its similarities and differences regarding ISO certification. PMID:26772826

  8. Advances in reference and transfer dosimetry

    All prerequisites are now in place to create a fundamentally and radically different type of calibration service for the radiation processing industry. Advancements in dosimetry and information technology can be combined to provide industry with on-line calibrations, on demand at a low cost. The remote calibration service will serve as a basis for other areas of metrology. (Author)

  9. From Evaluation to Accreditation

    Rasmussen, Palle

    for policy. In the state controlled and public financed Danish higher education system quality assessment became institutionalised in a national agency, the "evaluation centre", which was to do recurrent assessment of all higher education programmes. This was later given up. Recently accreditation of...

  10. Collection of abstracts. 6. national symposium on radiation dosimetry

    Abstracts are given of the total of 137 papers presented at the symposium. The papers discussed radiation dosimetry methods, dosemeters and detectors, the metrology and calibration of radiation sources, calibration standards, and radioactivity monitoring. (J.P.)

  11. Statistical analysis of personal dosimetry of exposed workers

    The dosimetry centers accredited by the Nuclear Safety Council (CSN) normally report overcoming legal limits, or some fraction thereof, but do not provide comparative dosimetric criteria indicating if assigned to a given dose is large TPE or small relative to that of their peers. In order to help to resolve the difficulties mentioned ds, it has developed an application that statistically processes the dosimetric data provided by the National Dosimetry Center. (Author)

  12. Calibration of individual dosemeters by using external beams of photon radiation. A nationwide survey among Personal Dosimetry Services, authorized by CSN

    A nationwide survey in 1995 among Personal Dosimetry Services, authorized by the Spanish Nuclear Safety Council (CSN), has led the Spanish Dosimetry Laboratories to review and update the dosimetric conversion coefficients and correction factors in use in Spain since 1987. The recommendations of the ICRU Report 47(1992) are discussed and adopted. In addition differences in back-scattering form IRCU tissue and PMMA phantoms are analysed. Analytical functions used to calculate conversion coefficients and back-scattering correction factors due to the use of different phantom materials are presented, together with the adopted final values. Firstly, the above mentioned parameters are applied to ISO narrow spectra series, which are discribed in this report. Secondly, differences between 1995 and 1987 values are also shown. (Author)

  13. ESR Dosimetry

    ESR dosimetry is widely used for several applications such as dose assessment in accidents, medical applications and sterilization of food and other materials. In this work the dosimetric properties of natural and synthetic Hydroxyapatite, Alanine, and 2-Methylalanine are presented. Recent results on the use of a K-Band (24 GHz) ESR spectrometer in dosimetry are also presented

  14. Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service - Tel. 72155 http://cern.ch/rp-dosimetry

  15. Dosimetry Service

    Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service Tel. 7 2155 http://cern.ch/rp-dosimetry

  16. Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service - Tel. 7 2155 http://cern.ch/rp-dosimetry

  17. Is gerontology ready for accreditation?

    Haley, William E; Ferraro, Kenneth F; Montgomery, Rhonda J V

    2012-01-01

    The authors review widely accepted criteria for program accreditation and compare gerontology with well-established accredited fields including clinical psychology and social work. At present gerontology lacks many necessary elements for credible professional accreditation, including defined scope of practice, applied curriculum, faculty with applied professional credentials, and resources necessary to support professional credentialing review. Accreditation with weak requirements will be dismissed as "vanity" accreditation, and strict requirements will be impossible for many resource-poor programs to achieve, putting unaccredited programs at increased risk for elimination. Accreditation may be appropriate in the future, but it should be limited to professional or applied gerontology, perhaps for programs conferring bachelor's or master's degrees. Options other than accreditation to enhance professional skills and employability of gerontology graduates are discussed. PMID:22289064

  18. Secondary calibration laboratory for dosimetry in levels of therapy at the University of Santiago; Laboratorio secundario de calibracion para dosimetria en niveles de terapia en la Universidad de Santiago

    Gomez Rodriguez, F.; Gonzalez Castano, D. M.; Pazos Alvarez, A.

    2011-07-01

    A basic inherent benefits provided by the existence of a traceability chain radiation in any application, add the legal requirement for hospitals as pointed to by the RO. 1566/1998, which sets quality standards in radiotherapy. The decree attributed to hospital specialists radio physics in article 10 the responsibility for determining the acceptance and initial reference state of radiation generating equipment for therapeutic purposes, and the establishment and implementation of quality control programs associated and technical and physical aspects of radiation dosimetry. Different international organizations such as ICRU and IAEA recommendations on maintaining the accuracy of the dose delivered to patients in general, should be placed at least 5% considering the whole chain irradiation. In order to achieve this purpose it is necessary to establish programs of quality control and calibration dosimetric regular basis. The protocol of the IAEA TRS398 recommended dose calibration in water because it is a quantity of interest closest to clinical use and allows a relative uncertainty in the calibration environment reduced to 1%.. (Author)

  19. Calibration of personal dosemeters in terms of the ICRU operational quantities

    The International Commission on Radiological Units and Measurements (ICRU) has defined several new operational quantities for radiation protection purposes. The quantities to be used for personal monitoring are defined at depths in the human body. Because these quantities are impossible to measure directly, the ICRU has recommended that personal dosemeters should be calibrated under simplified conditions on an appropriate phantom, such as the ICRU sphere. The US personal dosimetry accreditation programs make use of a 30 x 30 x 15 cm polymethymethacrylate (PMMA) phantom, therefore it is necessary to relate the response of dosemeters calibrated on this phantom to the ICRU operational quantities. Calculations of the conversion factors to compute dosemeter response in terms of the operational quantities have been performed using the code MCNP. These calculations have also been compared to experimental measurements using thermoluminescent (TLD) detectors

  20. SU-E-I-24: Design and Fabrication of a Multi-Functional Neck and Thyroid Phantom for Medical Dosimetry and Calibration

    Purpose: The purpose of this study is the design and fabrication of a multipurpose anthropomorphic neck and thyroid phantom for use in medical applications (i.e. quality control of images in nuclear medicine, and dosimetry). Methods: The designed neck phantom is composed of seven elliptic cylindrical slices with semi-major axis of 14 and semi-minor axis of 12.5 cm, each having the thickness of 2cm. Thyroid gland, bony part of the neck, and the wind pipe were also built inside the neck phantom. Results: The phantom contains some removable plugs,inside and at its surface to accommodate the TLD chips with different shapes and dimensions, (i.e. rod, cylindrical and cubical TLD chips)for the purpose of medical dosimetry (i.e. in radiology, radiotherapy, and nuclear medicine). For the purpose of quality control of images in nuclear medicine, the removable thyroid gland was built to accommodate the radioactive iodine. The female and male thyroid glands were built in two sizes separately. Conclusion: The designed phantom is a multi-functional phantom which is applicable for dosimetry in diagnostic radiology, radiotherapy, and quality control of images in nuclear medicine

  1. Third conference on radiation protection and dosimetry

    1991-01-01

    This conference has been designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To partly fulfill these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection has been prepared. General topics include external dosimetry, internal dosimetry, instruments, regulations and standards, accreditation and test programs, research advances, and applied program experience. This publication provides a summary of the technical program and a collection of abstracts of the oral presentations.

  2. Third conference on radiation protection and dosimetry

    This conference has been designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To partly fulfill these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection has been prepared. General topics include external dosimetry, internal dosimetry, instruments, regulations and standards, accreditation and test programs, research advances, and applied program experience. This publication provides a summary of the technical program and a collection of abstracts of the oral presentations

  3. Radio-analysis. Applications: biological dosimetry

    Radioisotopes have revolutionized the medical biology. Radio-immunology remains the reference measurement of the infinitely small in biology. Constant efforts have been performed to improve the simpleness, detectability and fastness of the method thanks to an increasing automation. This paper presents: 1 - the advantages of compounds labelling and the isotopic dilution; 2 - the antigen-antibody system: properties, determination of the affinity constant using the Scatchard method; 3 - radio-immunologic dosimetry: competitive dosimetry (radioimmunoassay), calibration curve and mathematical data processing, application to the free thyroxine dosimetry, immunoradiometric dosimetry (immunoradiometric assay), evaluation of the analytical efficiency of a radioimmunoassay; 4 - detection of the radioactive signal (solid and liquid scintillation). (J.S.)

  4. Results of the dosimetry intercomparison

    The appropriate way to verify the accuracy of the results of dose reported by the laboratories that offer lend personal dosimetry service is in the periodic participation of round of intercomparison dosimetry, undertaken by laboratories whose standards are trace (Secondary Laboratory). The Laboratory of External Personal Dosimetry of the CNEA-PY has participated in three rounds of intercomparison. The first two were organized in the framework of the Model Project RLA/9/030 RADIOLOGICAL WASTE SECURITY, and the irradiations were carried out in the Laboratory of Regional Calibration of the Center of Nuclear Technology Development, Belo Horizonte-Brazil (1998) and in the National Laboratory of Metrology of the ionizing radiations of the Institute of Radioprotection and Dosimetry, Rio de Janeiro-Brazil (1999). The third was organized by the IAEA and the irradiations were made in the Physikalisch-Technische Bundesanstalt PTB, Braunschweig - Federal Republic of Germany (1999-2000)

  5. Accredited dose measurements for validation of radiation sterilized products

    Miller, A.

    1993-01-01

    for control of radiation sterilization. The accredited services include: 1. 1. Irradiation of dosimeters and test samples with cobalt-60 gamma rays. 2. 2. Irradiation of dosimeters and test samples with 10 MeV electrons. 3. 3. Issue of and measurement with calibrated dosimeters. 4. 4. Measurement...

  6. Dosimetry in diagnostic radiology

    Dosimetry is an area of increasing importance in diagnostic radiology. There is a realisation amongst health professionals that the radiation dose received by patients from modern X-ray examinations and procedures can be at a level of significance for the induction of cancer across a population, and in some unfortunate instances, in the acute damage to particular body organs such as skin and eyes. The formulation and measurement procedures for diagnostic radiology dosimetry have recently been standardised through an international code of practice which describes the methodologies necessary to address the diverging imaging modalities used in diagnostic radiology. Common to all dosimetry methodologies is the measurement of the air kerma from the X-ray device under defined conditions. To ensure the accuracy of the dosimetric determination, such measurements need to be made with appropriate instrumentation that has a calibration that is traceable to a standards laboratory. Dosimetric methods are used in radiology departments for a variety of purposes including the determination of patient dose levels to allow examinations to be optimized and to assist in decisions on the justification of examination choices. Patient dosimetry is important for special cases such as for X-ray examinations of children and pregnant patients. It is also a key component of the quality control of X-ray equipment and procedures.

  7. Performance testing of dosimetry processors, status of NRC rulemaking for improved personnel dosimetry processing, and some beta dosimetry and instrumentation problems observed by NRC regional inspectors

    Early dosimetry processor performance studies conducted between 1967 and 1979 by several different investigators indicated that a significant percentage of personnel dosimetry processors may not be performing with a reasonable degree of accuracy. Results of voluntary performance testing of US personnel dosimetry processors against the final Health Physics Society Standard, Criteria for Testing Personnel Dosimetry Performance by the University of Michigan for the Nuclear Regulatory Commission (NRC) will be summarized with emphasis on processor performance in radiation categories involving beta particles and beta particles and photon mixtures. The current status of the NRC's regulatory program for improved personnel dosimetry processing will be reviewed. The NRC is proposing amendments to its regulations, 10 CFR Part 20, that would require its licensees to utilize specified personnel dosimetry services from processors accredited by the National Voluntary Laboratory Accreditation Program of the National Bureau of Standards. Details of the development and schedule for implementation of the program will be highlighted. Finally, selected beta dosimetry and beta instrumentation problems observed by NRC Regional Staff during inspections of NRC licensed facilities will be discussed

  8. Dosimetry for electron beam sterilization

    According to ISO 11137-1 (sect 4.3.4) dosimetry used in the development, validation and routine control of the sterilization process shall have measurement traceability to national or international standards and shall have a known level of uncertainty. It can only be obtained through calibration of the dosimeters. In presented lecture different types of dosimeter systems for electron beams (calorimeters, radiochromic film dosimeters, alanine / EPR) and their calibration are described

  9. Mammography accreditation program

    In the mid-1980's, the movement toward the use of dedicated mammography equipment provided significant improvement in breast cancer detection. However, several studies demonstrated that this change was not sufficient to ensure optimal image quality at a low radiation dose. In particular, the 1985 Nationwide Evaluation of X-ray Trends identified the wide variations in image quality and radiation dose, even from dedicated units. During this time period, the American Cancer Society (ACS) launched its Breast Cancer Awareness Screening Campaign. However, there were concerns about the ability of radiology to respond to the increased demand for optimal screening examinations that would result from the ACS program. To respond to these concerns, the ACS and the American College of Radiology (ACR) established a joint committee on mammography screening in 1986. After much discussion, it was decided to use the ACR Diagnostic Practice Accreditation Program as a model for the development of a mammography accreditation program. However, some constraints were required in order to make the program meet the needs of the ACS. This voluntary, peer review program had to be timely and cost effective. It was determined that the best way to address these needs would be to conduct the program by mail. Finally, by placing emphasis on the educational nature of the program, it would provide an even greater opportunity for improving mammographic quality. The result of this effort was that, almost six years ago, in May 1987, the pilot study for the ACR Mammography Accreditation Program (MAP) began, and in August of that year, the first applications were received. In November 1987, the first 3-year accreditation certificates were awarded

  10. Mammography accreditation program

    Wilcox, P.

    1993-12-31

    In the mid-1980`s, the movement toward the use of dedicated mammography equipment provided significant improvement in breast cancer detection. However, several studies demonstrated that this change was not sufficient to ensure optimal image quality at a low radiation dose. In particular, the 1985 Nationwide Evaluation of X-ray Trends identified the wide variations in image quality and radiation dose, even from dedicated units. During this time period, the American Cancer Society (ACS) launched its Breast Cancer Awareness Screening Campaign. However, there were concerns about the ability of radiology to respond to the increased demand for optimal screening examinations that would result from the ACS program. To respond to these concerns, the ACS and the American College of Radiology (ACR) established a joint committee on mammography screening in 1986. After much discussion, it was decided to use the ACR Diagnostic Practice Accreditation Program as a model for the development of a mammography accreditation program. However, some constraints were required in order to make the program meet the needs of the ACS. This voluntary, peer review program had to be timely and cost effective. It was determined that the best way to address these needs would be to conduct the program by mail. Finally, by placing emphasis on the educational nature of the program, it would provide an even greater opportunity for improving mammographic quality. The result of this effort was that, almost six years ago, in May 1987, the pilot study for the ACR Mammography Accreditation Program (MAP) began, and in August of that year, the first applications were received. In November 1987, the first 3-year accreditation certificates were awarded.

  11. FIS accreditation guidelines

    Ojanen, Pinja

    2010-01-01

    The International Ski Federation (FIS) was founded to support and develop the sport of skiing 100 years ago. Since then skiing has grown in importance and has become more popular. Nowadays ski companies, athletes and family members, but also fan clubs, national ski associations, sponsors and local organizers get involved for a sporting event. The aim of this project-based thesis was to create guidelines and make the FIS accreditation system as user-friendly as possible. For the groups (ser...

  12. Dosimetry for Electron Beam Applications

    Miller, Arne

    1983-01-01

    This report describes two aspects of electron bean dosimetry, on one hand developaent of thin fil« dosimeters and measurements of their properties, and on the other hand developaent of calorimeters for calibration of routine dosimeters, e.g. thin films. Two types of radiochromic thin film dosimet...

  13. Accreditation: recognition for quality training

    A three-step accreditation program for personnel training has upgraded nuclear power plant instruction and standards. The accreditation process includes self-evaluation, Institute of Nuclear Power Operations (INPO) evaluation, and an Accrediting Board decision. During the self-evaluation phase, utilities compare their training with standardized criteria to identify any weaknesses and implement solutions. INPO participation and assistance at this point introduces objective appraisal at an early stage and ensures that adequate documentation will be available for the INPO evaluation

  14. Dosimetry Service

    Dosimetry Service

    2004-01-01

    We wish to remind the people who are invited to the dosimetry service to exchange the new CERN dosimeter that the hours are from Monday to Friday 8:30 to 11:00 and 14:00 to 16:00. For all other services we are at your disposition from 8:30 to 12:00 and 14:00 to 17:00. Do not forget to read your dosimeter. A regular read-out is indispensable in order to ensure a periodic monitoring of personal dose. This read-out should be done during the first week of every month. Thank you for your cooperation. The personnel of the Dosimetry Service wish you a Merry Christmas and a Happy New Year. Dosimetry Service Tel. 767 21 55 http://cern.ch/rp-dosimetry

  15. 热释光剂量测量系统检定的质量保证及刻度因子的应用%Quality assurance for verification of thermoluminescence dosimetry system and application of calibration factors

    李秀芹; 赵进沛; 米宁; 杨新芳; 侯金兵

    2012-01-01

    [ Objective] To ensure the reliability of individual dose monitoring data of radiation exposed workers, explore the influencing factors during verification process of thermoluminescence (TL) dosimetry system, calculate the linearity and the calibration factors of different energy respond, and determine the calibration factors that were suitable to different types of radiation exposed workers. [Methods] According to JJG 593-2006, two schemes were designed for verification. Scheme one; the chosen TL detectors were placed directly on the phantom and irradiated by different dosage 137 Cs--y ray radiation. Scheme two; the chosen TL detectors were worn by boxes, then placed on the phantom and irradiated by different dosage 137Cs~7 radiation and different energy X rays. The linearity and calibration factors were calculated. [ Results]There was significant difference between the detectors placed directly on the phantom and detectors worn by boxes, and the difference between calibration factors of different energy respond was significant , too. [ Conclusion] In the course of the verification of TL dosimetry system, the balance condition should be controlled strictly , and it is important to adopt the detector boxes for balance. The low energy X-ray radiation calibration factors should be used in radiation diagnosis group, and the -/-ray radiation calibration factors is suitable to radiation therapy group. The application of two calibration factors can get more accurate monitoring data.%目的 为保证辐射受照人员个人剂量监测数据的可靠性,探讨热释光剂量测量系统检定过程影响因素,计算线性和不同能响刻度因子,确定不同类别照射群体所使用的刻度因子.方法 依据标准JJG 593 - 2006,设计2种方案进行系统检定.方案1:已筛选退火后的探测器片放于有机玻璃平衡板中,分别予以不同剂量的137 Cs γ射线照射;方案2:将探测器片放于剂量计盒中,置于与方案1相同位置,予γ

  16. Dosimetry methods

    McLaughlin, W.L.; Miller, A.; Kovacs, A.; Mehta, K. K.

    Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application.......Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application....

  17. Dosimetry Service

    Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter at least once every month. A regular read-out is indispensable to ensure periodic monitoring of your personal dose. You must read your dosimeter even if you have not visited the controlled areas. Film badges are no longer valid at CERN and holders of film badges are no longer allowed to enter the controlled radiation areas or work with a source. Dosimetry Service Tel. 72155 http://cern.ch/rp-dosimetry

  18. Dosimetry in radiotherapy. V.2

    A series of symposia on dosimetry in medicine and biology have been held by the IAEA in co-operation with WHO. The present symposium was the first one focusing on ''Dosimetry in Radiotherapy''. The papers presented reflected the different steps in the calibration chain such as the calibration standards established by the National Standards Laboratories and the conversion of the reading of calibrated instruments to the desired quantity, i.e. absorbed dose to water at a reference point in the user's beam at the radiotherapy clinic. The programme further examined the procedures necessary for optimization of the treatment of the patient, such as treatment planning methods, dose distribution studies, new techniques of dose measurement, improvements in the physical dose distributions/conformation therapy and special problems involved in total body treatments. Results of quality assurance in radiotherapy were presented from local hospitals as well as from national and international studies. Refs, figs and tabs

  19. Dosimetry in radiotherapy. V.1

    A series of symposia on dosimetry in medicine and biology have been held by the IAEA in co-operation with WHO. The present symposium was the first one focusing on ''Dosimetry in Radiotherapy''. The papers presented reflected the different steps in the calibration chain such as the calibration standards established by the National Standards Laboratories and the conversion of the reading of calibrated instruments to the desired quantity, i.e. absorbed dose to water at a reference point in the user's beam at the radiotherapy clinic. The programme further examined the procedures necessary for optimization of the treatment of the patient, such as treatment planning methods, dose distribution studies, new techniques of dose measurement, improvements in the physical dose distributions/conformation therapy and special problems involved in total body treatments. Results of quality assurance in radiotherapy were presented from local hospitals as well as from national and international studies. Refs, figs and tabs

  20. 42 CFR 488.8 - Federal review of accreditation organizations.

    2010-10-01

    ... organization proposes to adopt new requirements or change its survey process. An accreditation organization... national accreditation organization. CMS's review and evaluation of a national accreditation organization... criteria— (1) The equivalency of an accreditation organization's accreditation requirements of an entity...

  1. Mammography calibration: Factor or fit?

    Dose measurements in mammography x-ray have become more important and a basic path in quality assurance programmes. It is recognized by the international guidelines that it is necessary to have calibration services offered for mammography beams in order to help the improvement of the clinical diagnosis. Major efforts have been made by several laboratories in order to establish an appropriate and traceable calibration infrastructure and to provide the basis for a quality control programme in mammography. The indication of a dosimeter, whose reference point is positioned at the point of test, is compared with the conventional true value of the quantity to be measured. The calibration coefficient is then the ratio of the conventional true value to the indicated. The Primary Standard Dosimetry Laboratory - PSDL or the Secondary Standard Dosimetry Laboratory - SSDL provides the calibration coefficient of the dosimeters in reference to the Half Value Layers - HVL implemented in their laboratories. The dosimetry calibration data is enough when the user has the same system as the laboratory where the ionization chamber has been calibrated. However, there are other calibration systems that have different calibration qualities implemented using different combinations of anode and filter and, therefore, there is no direct relation with the calibration coefficient. How to deal with this? There are two different ways to obtain calibration coefficients when the user's implemented qualities are different from the calibration laboratory's qualities. The first is the interpolation of each calibration coefficient stated in the certificate. The second is the fit of all calibration coefficients, separately for non-attenuated and attenuated beam qualities, to obtain a function by which the calibration coefficients can be determined at each beam quality. The second one includes the statistical fluctuation. The dosimetry calibration data must fit an analytical form, as for example a

  2. DOE standard: The Department of Energy Laboratory Accreditation Program for radiobioassay

    This technical standard describes the US Department of Energy Laboratory Accreditation Program (DOELAP) for Radiobioassay, for use by the US Department of Energy (DOE) and DOE Contractor radiobioassay programs. This standard is intended to be used in conjunction with the general administrative technical standard that describes the overall DOELAP accreditation process--DOE-STD-1111-98, Department of Energy Laboratory Accreditation Program Administration. This technical standard pertains to radiobioassay service laboratories that provide either direct or indirect (in vivo or in vitro) radiobioassay measurements in support of internal dosimetry programs at DOE facilities or for DOE and DOE contractors. Similar technical standards have been developed for other DOELAP dosimetry programs. This program consists of providing an accreditation to DOE radiobioassay programs based on successful completion of a performance-testing process and an on-site evaluation by technical experts. This standard describes the technical requirements and processes specific to the DOELAP Radiobioassay Accreditation Program as required by 10 CFR 835 and as specified generically in DOE-STD-1111-98

  3. Experimental and theoretical considerations on the calibration factor K between α-activity concentration and track density for application in radon dosimetry

    A new version of the measurement of the calibration factor, K is described between radon activity concentration and track density. The use of Solid State Nuclear Track Detectors (SSNTDs) is one of the most convenient techniques to assess the radiation level of α-activities in the environment. Exposed plastic films are chemically and electrochemically etched in an alkali solution and the α-tracks are evaluated under optical microscope. The detailed procedure for this study and the calibration of the etched films for conversion of track density to radon exposure in (Bq * m-3) are given. It was found the experimental and theoretical values of K were 1.37 and 1.27 (track * cm-2 * kBq-1 * h -1 * m3), respectively, for plastic detectors CR-39. (author) 16 refs.; 5 figs.; 4 tabs

  4. Environmental dosimetry of radon-222 and daughters: measurement of absolute calibration factors of CR-39 considering the plate-out effects and environmental factors

    The subject of this work concerns with the measurement of absolute calibration factors for the use of CR-39 as an absolute detector in indoor and daughters monitoring. Up to now the usefulness of calibration factors was restricted to environmental conditions equal (or very close) to those worthing during their determinations. This fact is consequence of the difficulties related to the understanding of the plate-out properties of radon daughters activity in the air. The plate-out effects on radon daughters monitoring performed by SSNTDs are studied. Our experimental results are in agreement with those of other authors about the great sensitivity of CR-39 to the plate-out effects, fact that recommended its use in this work. Being succeeded in the employment of CR-39 as an alpha-spectrometer we concluded that some important information (like the radon daughters deposition rates on the walls of an environment) can be achieved. The knowledge about the behavior of plate-out made possible the determination of the ranges in zenithal angle and energy where CR-39 can detect alpha-particles with efficiency of 100%, at our conditions of track observation. In this way, we obtained calibration factors for CR-39 that are weakly dependent on environmental conditions. We think that these results can contribute to the improvement of RD (Radiation Detector) detection techniques. (author). 159 refs, 106 figs, 05 tabs

  5. 7 CFR 983.1 - Accredited laboratory.

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Accredited laboratory. 983.1 Section 983.1 Agriculture..., ARIZONA, AND NEW MEXICO Definitions § 983.1 Accredited laboratory. An accredited laboratory is a laboratory that has been approved or accredited by the U.S. Department of Agriculture....

  6. CAECC Software Testing Laboratory Accredited by CNAL

    2005-01-01

    Software Testing Laboratory of China Aerospace Engineering and Consultation Center (CAECC) is accredited by China National Accreditation Board for Laboratories (CNAL) as the first such laboratory in domestic space industry. Since CNAL is a member of International Laboratory Accreditation Cooperation (ILAC),software testing reports certificated to CAECC are recognized by 45 laboratory accreditation organizations in AsiaPacific region, Europe and America.

  7. Dosimetry Service

    2005-01-01

    The Dosimetry Service will be closed every afternoon the week of 21st to 25th February 2005. The opening hours will be from 8.30 am to 12.00 midday. Don't forget to read your dosimeter, as regular read-outs are indispensable to ensure periodic monitoring of personal doses. Thank you for you cooperation.

  8. Radiation dosimetry in Cyprus

    Cyprus is a small island in the eastern part of the mediterranean sea with a population of 700,000. A small Physics Department in the Nicosia General Hospital is responsible for all matters related to ionising radiation. The main applications of ionising radiation are in medicine, some applications of radioisotopes in agriculture and hydrology research and very few applications in industry with sealed radiation sources. The same problems in radiation dosimetry are encountered as in any other countries but on a smaller scale. These have to be solved locally, because of the island's geographic isolation. All the infrastructure including Secondary Standard Dosemeters, field instruments and calibration sources is needed in order to achieve this, but the financial resources available are very limited. For this reason improvisation is often necessary. The Co-60 and other X-ray units intended for radiotherapy or other clinical use, are used as radiation sources for dosimetry and calibration of the instruments. Simple, locally made phantoms are designed in order to decrease costs whenever possible. (author). 7 refs, 1 fig

  9. Basic physical data for neutron dosimetry

    Based on the results of a workshop on basic physical data for neutron dosimetry held in Rijswijk (The Netherlands) on 19-21 May 1976, this monograph reviews the current status in neutron dosimetry and the agreements that were reached on the use of some common basic physical parameters. As appendices are joint tables of kerma factors and a draft of a protocol for neutron dosimetry for radiobiological and medical applications. Main topic treated: source and field characteristics; cross sections and mass energy transfer coefficients; measurements and calculations; detector response, measurements and calculations; dose distributions in phantoms for a limited set of conditions; standardization, calibration and intercomparison

  10. Calibration of farmer dosemeters

    The Farmer Dosemeters of Atomic Energy Medical Centre (AEMC) Jamshoro were calibrated in the Secondary Standard Dosimetry Laboratory (SSDL) at PINSTECH, using the NPL Secondary Standard Therapy level X-ray exposure meter. The results are presented in this report. (authors)

  11. Radiation monitor calibration technique

    Reference radiations in the Secondary Standard Dosimetry Laboratory, OAEP have been improved and modified by employing lead attenuators. To identify low-level exposure rate, shadow-cone method has been applied. The secondary standard dosemeter has been used periodically to check the constancy of reference radiations to assure the calibration of dosemeters and dose-ratemeters used for radiation protection

  12. Activities developed by the biological dosimetry laboratory of the Autoridad Regulatoria Nuclear - ARN of Argentina; Actividades desarrolladas por el laboratorio de dosimetria biologica de la Autoridad Regulatoria Nuclear de Argentina

    Radl, A.; Sapienza, C.E.; Taja, M.R.; Bubniak, R.; Deminge, M.; Di Giorgio, M., E-mail: csapienza@arn.gob.ar [Autoridad Regulatoria Nuclear (ARN), Buenos Aires (Argentina)

    2013-07-01

    Biological dosimetry (DB) allows to estimate doses absorbed in individuals exposed to ionizing radiation through the quantification of stable and unstable chromosome aberrations (SCA and UCA). The frequency of these aberrations is referred to a calibration dose response curve (in vitro) to determine the doses of the individual to the whole body. The DB is a necessary support for programs of national radiation protection and response systems in nuclear or radiological emergencies in the event of accidental or incidental, single overexposure or large scale. In this context the Laboratory of Dosimetry Biological (LDB) of the Authority Regulatory Nuclear (ARN) Argentina develops and applies different dosimeters cytogenetic from four decades ago. These dosimeters provide a fact more within the whole of the information necessary for an accidental, complementing the physical and clinical dosimetry exposure assessment. The most widely used in the DB biodosimetric method is the quantification of SCA (dicentrics and rings Central) from a sample of venous blood. The LDB is accredited for the trial, under rules IRAM 301: 2005 (ISO / IEC 17025: 2005) and ISO 19238:2004. Test applies to the immediate dosimetry evaluation of acute exposures, all or a large part of the body in the range 0,1-5 Gy. In this context the LDB is part of the Latin American network of DB (LBDNet), BioDoseNet-who and response system in radiological emergencies and nuclear IAEA-RANET, being enabled to summon the LBDNet if necessary.

  13. Relative dosimetry by Ebt-3

    In the present work relative dosimetry in two linear accelerator for radiation therapy was studied. Both Varian Oncology systems named Varian Clinac 2100-Cd and MLC Varian Clinac i X were used. Gaf Chromic Ebt-3 film was used. Measurements have been performed in a water equivalent phantom, using 6 MV and 18 MV photon beams on both Linacs. Both calibration and Electron irradiations were carried out with the ionization chamber placed at the isocenter, below a stack of solid water slabs, at the depth of dose maximum (D max), with a Source-to-Surface Distance (SSD) of 100 cm and a field size of 10 cm x 10 cm. Calibration and dosimetric measurements photons were carried out under IAEA-TRS 398 protocol. Results of relative dosimetry in the present work are discussed. (Author)

  14. Advances in biomedical dosimetry

    Full text: Radiation dosimetry, the accurate determination of the absorbed dose within an irradiated body or a piece of material, is a prerequisite for all applications of ionizing radiation. This has been known since the very first radiation applications in medicine and biology, and increasing efforts are being made by radiation researchers to develop more reliable, effective and safe instruments, and to further improve dosimetric accuracy for all types of radiation used. Development of new techniques and instrumentation was particularly fast in the field of both medical diagnostic and therapeutic radiology. Thus, in Paris in October the IAEA held the latest symposium in its continuing series on dosimetry in medicine and biology. The last one was held in Vienna in 1975. High-quality dosimetry is obviously of great importance for human health, whether the objectives lie in the prevention and control of risks associated with the nuclear industry, in medical uses of radioactive substances or X-ray beams for diagnostic purposes, or in the application of photon, electron or neutron beams in radiotherapy. The symposium dealt with the following subjects: General aspects of dosimetry; Special physical and biomedical aspects; Determination of absorbed dose; Standardization and calibration of dosimetric systems; and Development of dosimetric systems. The forty or so papers presented and the discussions that followed them brought out a certain number of dominant themes, among which three deserve particular mention. - The recent generalization of the International System of Units having prompted a fundamental reassessment of the dosimetric quantities to be considered in calibrating measuring instruments, various proposals were advanced by the representatives of national metrology laboratories to replace the quantity 'exposure' (SI unit = coulomb/kg) by 'Kerma' or 'absorbed dose' (unit joule/kg, the special name of which is 'gray'), this latter being closer to the practical

  15. Calibration of CT density values in dosimetry verification of intensity modulated radiation therapy%调强适形放射治疗剂量验证中CT密度值的校准分析

    庄名赞; 吴仁华; 邱庆春; 彭逊; 陆佳扬; 陈志坚

    2011-01-01

    Objecfive Based on intensity modulated radiation therapy (IMRT)phantom,the impact of CT-to-density conversion curve on dosimetry verification of IMRT is investigated and calibrated.Methods The electron density phantom was used to establish the CT-to-density conversion curve in radiation treatment planning system.IMRT plans of 12 nasopharynx carcinoma patients were chosen,copied to IMRT phantom and computed for the dose distribution.For each plan a measured point was put at the place where the dose was well-distributed and its dose value was measured using the ionization chamber.The physical density of IMRT phantom and its CTvalue were input into the planning system,to make a calibration for the CT-to-density conversion curve.The dose distribution was recomputed for each IMRT plan.Other parameters were kept the same in the plans and the differences between the computed dose values before and after correction were compared with the measured values.Results In 12 nasopharynx carcinoma IMRT plans,the average error of computed dose values was 1.96%±0.87% before correction and 0.63%±0.74%after correction,compared with measured values.The error between measured values and computed values after correction was less than ±2% whereas the maximum error of computed values before correction was 3.24%.Conclusions The computed dose values are closer to the measured values when using the calibrated CT-to-density conversion curve.The CT density values of IMRT phantom should be verified before usage,so as to increase the accuracy of IMRT dosimetry verification.%目的 基于调强适形放射治疗(IMRT)验证体模,分析放射治疗计划系统中CT密度转换曲线在IMRT剂量验证中的影响,并加以校准.方法 利用CT电子密度体模刻度计划系统中的CT密度转换曲线,取12例鼻咽癌患者的IMRT计划,分别移植至IMRT验证体模,计算剂量分布,并于剂量均匀处放置测量点,利用电离室测量出其实际剂量.将IMRT验证体模的物

  16. Technical basis document for internal dosimetry

    This document provides the technical basis for the Chem-Nuclear Geotech (Geotech) internal dosimetry program. Geotech policy describes the intentions of the company in complying with radiation protection standards and the as low as reasonably achievable (ALARA) program. It uses this policy and applicable protection standards to derive acceptable methods and levels of bioassay to assure compliance. The models and computational methods used are described in detail within this document. FR-om these models, dose- conversion factors and derived limits are computed. These computations are then verified using existing documentation and verification information or by demonstration of the calculations used to obtain the dose-conversion factors and derived limits. Recommendations for methods of optimizing the internal dosimetry program to provide effective monitoring and dose assessment for workers are provided in the last section of this document. This document is intended to be used in establishing an accredited dosimetry program in accordance with expected Department of Energy Laboratory Accreditation Program (DOELAP) requirements for the selected radionuclides provided in this document, including uranium mill tailing mixtures. Additions and modifications to this document and procedures derived FR-om this document are expected in the future according to changes in standards and changes in programmatic mission

  17. MO-A-BRD-07: Feasibility of X-Ray Acoustic Computed Tomography as a Tool for Calibration and In Vivo Dosimetry of Radiotherapy Electron and Photon Beams

    Purpose: This work simulates radiation-induced acoustic waves to assess the feasibility of x-ray acoustic computed tomography (XACT) as a dosimeter. XACT exploits the phenomenon that acoustic waves with amplitude proportional to the dose deposited are induced following a radiation pulse. After detecting these acoustic waves with an ultrasound transducer, an image of the dose distribution can be reconstructed in realtime. Methods: Monte Carlo was used to simulate the dose distribution for monoenergetic 6 MeV photon and 9 MeV electron beams incident on a water tank. The dose distribution for a prostate patient planned with a photon 4-field box technique was calculated using clinical treatment planning software. All three dose distributions were converted into initial pressure distributions, and transportation of the induced acoustic waves was simulated using an open-source toolkit. Ideal transducers were placed around the circumference of the target to detect the acoustic waves, and a time reversal reconstruction algorithm was used to obtain an XACT image of the dose for each radiation pulse. Results: For the photon water tank relative dosimetry case, it was found that the normalized acoustic signal amplitude agreed with the normalized dose at depths from 0 cm to 10 cm, with an average percent difference of 0.5%. For the reconstructed in-plane dose distribution of an electron water tank irradiation, all pixels passed a 3%–3 mm 2D gamma test. The reconstructed prostate dose distribution closely resembled the plan, with 89% of pixels passing a 3%–3 mm 2D gamma test. For all situations, the amplitude of the induced acoustic waves ranged from 0.01 Pa to 1 Pa. Conclusion: Based on the amplitude of the radiation-induced acoustic waves and accuracy of the reconstructed dose distributions, XACT is a feasible technique for dosimetry in both calibration and in vivo environments for photon and electron beams and merits further investigation. Funding from NSERC, CIHR and Mc

  18. Quality management system in the CIEMAT radiation dosimetry service

    This paper describes the activities realised by the CIEMAT Radiation Dosimetry Service (SDR) for the implementation of a quality management system (QMS) in order to achieve compliance with the requirements of ISO/IEC 17025 and to apply for the accreditation for testing measurements of radiation dose. SDR has decided the accreditation of the service as a whole and not for each of its component laboratories. This makes it necessary to design a QMS common to all, thus ensuring alignment and compliance with standard requirements, and simplifying routine works as possible. (authors)

  19. Dosimetry Service

    Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter every month at least once and preferably during the first week. A regular read-out is indispensable in order to ensure a periodic monitoring of the personal dose. You should read your dosimeter even if you have not visited the controlled areas. If you still have the old dosimeter (film badge), please send it immediately for evaluation to us (Bdg 24 E-011). After January 2005 there will be no developing process for the old film system. Information for Contractors: Please remember also to bring the form ‘Confirm Reception of a CERN Dosimeter' signed with ‘Feuille d'enregistrement du CERN'. Without these forms the dosimeter cannot be assigned. Thank you for your cooperation. Dosimetry Service Tel 767 2155 http://cern.ch/rp-dosimetry

  20. Hematological dosimetry

    The principles of hematological dosimetry after acute or protracted whole-body irradiation are reviewed. In both cases, over-exposure is never homogeneous and the clinical consequences, viz medullary aplasia, are directly associated with the mean absorbed dose and the seriousness and location of the overexposure. The main hematological data required to assess the seriousness of exposure are the following: repeated blood analysis, blood precursor cultures, as indicators of whole-body exposure; bone marrow puncture, medullary precursor cultures and medullary scintigraphy as indicators of the importance of a local over-exposure and capacity for spontaneous repair. These paraclinical investigations, which are essential for diagnosis and dosimetry, are also used for surveillance and for the main therapeutic issues

  1. Dosimetry Service

    2004-01-01

    We wish to remind the people who are invited to the Dosimetry Service to exchange the new CERN dosimeter that the hours are from Monday to Friday 8.30 to 11.00 and 14.00 to 16.00. Do not forget to read your dosimeter. The reading should be done during the first week of every month. Thank you for your cooperation.

  2. Radiation dosimetry.

    Cameron, J.

    1991-01-01

    This article summarizes the basic facts about the measurement of ionizing radiation, usually referred to as radiation dosimetry. The article defines the common radiation quantities and units; gives typical levels of natural radiation and medical exposures; and describes the most important biological effects of radiation and the methods used to measure radiation. Finally, a proposal is made for a new radiation risk unit to make radiation risks more understandable to nonspecialists.

  3. An accredited infrastructure for clearance of decommissioning waste

    The nuclear research reactors and a hot-cell facility at the Riso site in Denmark have been closed and are in the process of being decommissioned. This has prompted the development of an accredited infrastructure called the Clearance Function. This function is responsible for the activity concentration measurements of the clearance candidates and for the demonstration of compliance with the clearance levels for the released objects. The Clearance Function comprises laboratory facilities, measuring equipment, measuring procedures, waste handling software, software for clearance related calculations and trained personnel. An accreditation of the Clearance Function has been granted from the accreditation body, DANAK, according to the international standard ISO/IEC 17025:2005. DANAK is a member of ILAC, the International Laboratory Accreditation Cooperation. The Clearance Function has been accredited to measure surface-specific and mass-specific activities using surface contamination monitors and high purity germanium detectors. The germanium detectors are characterised and in each measurement they are calibrated using the ISOCS (registered) calibration software. Activity concentration measurements can be made on items as a whole (one or several combined measurements) or on samples from an item. In the latter case a statistical method is used to evaluate whether the activity concentration is above or below the clearance level. The paper describes the different elements of the Clearance Function and the processing of items through the flow routes depending on the likely activity content and the distribution of activity. It is shown how uncertainties are incorporated in the clearance criteria. Experience from the first year of operation of the Clearance Function is reported. (author)

  4. An accredited infrastructure for clearance of decommissioning waste

    The nuclear research reactors and a hot-cell facility at the Riso site in Denmark have been closed and are in the process of being decommissioned. This has prompted the development of an accredited infrastructure called the Clearance Function. This function is responsible for the activity concentration measurements of the clearance candidates and for the demonstration of compliance with the clearance levels for the released objects. The Clearance Function comprises laboratory facilities, measuring equipment, measuring procedures, waste handling software, software for clearance related calculations and trained personnel. An accreditation of the Clearance Function has been granted from the accreditation body, DANAK, according to the international standard ISO/IEC 17025:2005. DANAK is a member of ILAC, the International Laboratory Accreditation Cooperation. The Clearance Function has been accredited to measure surface-specific and mass-specific activities using surface contamination monitors and high purity germanium detectors. The germanium detectors are characterised and in each measurement they are calibrated using the ISOCS calibration software. Activity concentration measurements can be made on items as a whole (one or several combined measurements) or on samples from an item. In the latter case a statistical method is used to evaluate whether the activity concentration is above or below the clearance level. The paper describes the different elements of the Clearance Function and the processing of items through the flow routes depending on the likely activity content and the distribution of activity. It is shown how uncertainties are incorporated in the clearance criteria. Experience from the first year of operation of the Clearance Function is reported. (author)

  5. Dosimetry standards for radiation processing

    For irradiation treatments to be reproducible in the laboratory and then in the commercial environment, and for products to have certified absorbed doses, standardized dosimetry techniques are needed. This need is being satisfied by standards being developed by experts from around the world under the auspices of Subcommittee E10.01 of the American Society for Testing and Materials (ASTM). In the time period since it was formed in 1984, the subcommittee has grown to 150 members from 43 countries, representing a broad cross-section of industry, government and university interests. With cooperation from other international organizations, it has taken the combined part-time effort of all these people more than 13 years to complete 24 dosimetry standards. Four are specifically for food irradiation or agricultural applications, but the majority apply to all forms of gamma, x-ray, Bremsstrahlung and electron beam radiation processing, including dosimetry for sterilization of health care products and the radiation processing of fruits, vegetables, meats, spices, processed foods, plastics, inks, medical wastes and paper. An additional 6 standards are under development. Most of the standards provide exact procedures for using individual dosimetry systems or for characterizing various types of irradiation facilities, but one covers the selection and calibration of dosimetry systems, and another covers the treatment of uncertainties. Together, this set of standards covers essentially all aspects of dosimetry for radiation processing. The first 20 of these standards have been adopted in their present form by the International Organization of Standardization (ISO), and will be published by ISO in 1999. (author)

  6. Third conference on radiation protection and dosimetry. Program and abstracts

    1991-12-31

    This conference has been designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To partly fulfill these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection has been prepared. General topics include external dosimetry, internal dosimetry, instruments, regulations and standards, accreditation and test programs, research advances, and applied program experience. This publication provides a summary of the technical program and a collection of abstracts of the oral presentations.

  7. Radio-analysis. Applications: biological dosimetry; Radioanalyse. Applications: dosage biologique

    Bourrel, F. [CEA Saclay, INSTN, Institut National des Sciences et Techniques Nucleaires, 91 - Gif-sur-Yvette (France); Courriere, Ph. [UFR de Pharmacie, 31 - Toulouse (France)

    2003-06-01

    Radioisotopes have revolutionized the medical biology. Radio-immunology remains the reference measurement of the infinitely small in biology. Constant efforts have been performed to improve the simpleness, detectability and fastness of the method thanks to an increasing automation. This paper presents: 1 - the advantages of compounds labelling and the isotopic dilution; 2 - the antigen-antibody system: properties, determination of the affinity constant using the Scatchard method; 3 - radio-immunologic dosimetry: competitive dosimetry (radioimmunoassay), calibration curve and mathematical data processing, application to the free thyroxine dosimetry, immunoradiometric dosimetry (immunoradiometric assay), evaluation of the analytical efficiency of a radioimmunoassay; 4 - detection of the radioactive signal (solid and liquid scintillation). (J.S.)

  8. Technical basis document for internal dosimetry

    Hickman, D P

    1991-01-01

    This document provides the technical basis for the Chem-Nuclear Geotech (Geotech) internal dosimetry program. Geotech policy describes the intentions of the company in complying with radiation protection standards and the as low as reasonably achievable (ALARA) program. It uses this policy and applicable protection standards to derive acceptable methods and levels of bioassay to assure compliance. The models and computational methods used are described in detail within this document. FR-om these models, dose- conversion factors and derived limits are computed. These computations are then verified using existing documentation and verification information or by demonstration of the calculations used to obtain the dose-conversion factors and derived limits. Recommendations for methods of optimizing the internal dosimetry program to provide effective monitoring and dose assessment for workers are provided in the last section of this document. This document is intended to be used in establishing an accredited dosi...

  9. Calibration of sources for alpha spectroscopy systems

    This paper describes the calibration methodology for measuring the total alpha activity of plane and thin sources with the Alpha Spectrometer for Silicon Detector in the Nuclear Measures and Dosimetry laboratory at IEAv/CTA. (author)

  10. Clinical dosimetry using mosfets

    Purpose: The use of metal oxide-silicon field effect transistors (MOSFETs) as clinical dosimeters is demonstrated for a number of patients with targets at different clinical sites. Methods and Materials: Commercially available MOSFETs were characterized for energy response, angular dependency of response, and effect of accumulated dose on sensitivity and some inherent properties of MOSFETs. The doses determined both by thermoluminescence dosimetry (TLD) and MOSFETs in clinical situation were evaluated and compared to expected doses determined by calculation. Results: It was observed that a standard calibration of 0.01 Gy/mV gave MOSFET determined doses which agreed with expected doses to within 5% at the 95% confidence limit for photon beams from 6 to 25 MV and electron beams from 5 to 14 MeV. An energy-dependent variation in response of up to 28% was observed between two orientations of a MOSFET. The MOSFET doses compared very well with the doses estimated by TLDs, and the patients tolerated MOSFETs very well. A standard deviation of 3.9% between expected dose and MOSFET determined dose was observed, while for TLDs the standard deviation was 5.1%. The advantages and disadvantages of using MOSFETs for clinical dosimetry are discussed in detail. Conclusion: It was concluded that MOSFETs can be used as clinical dosimeters and can be a good alternative to TLDs. However, they have limitations under certain clinical situations

  11. Radiation dosimetry and standards at the austrian dosimetry laboratory

    The Austrian Dosimetry Laboratory, established and operated in cooperation between the Austrian Research Center Seibersdorf and the Federal Office of Metrology and Surveying (Bundesamt and Eich- und Vermessungswesen) maintains the national primary standards for radiation dosimetry. Furthermore its tasks include routine calibration of dosemeters and dosimetric research. The irradiation facilities of the laboratory comprise three X-ray machines covering the voltage range from 5 kV to 420 kV constant potential, a 60Co teletherapy unit, a circular exposure system for routine batch calibration of personnel dosemeters with four gamma ray sources (60Co and 137Cs) and a reference source system with six gamma ray sources (60Co and 137Cs). In addition a set of calibrated beta ray sources are provided (147Pm, 204Tl and 90Sr). The dosimetric equipment consists of three free-air parallelplate ionization chambers serving as primary standards of exposure for the X-ray energy region, graphite cavity chambers with measured volume as primary standards for the gamma radiation of 137Cs and 60Co as well as different secondary standard ionization chambers covering the dose rate range from the natural background level up to the level of modern therapy accelerators. In addition for high energy photon and electron radiation a graphite calorimeter is provided as primary standard of absorbed dose. The principle experimental set-ups for the practical use of the standards are presented and the procedures for the calibration of the different types of dosemeters are described. (Author)

  12. Quality management system of secondary standards dosimetry laboratory in Sri Lanka

    Full text: Application of Quality Management System (QMS) of Secondary Standard Dosimetry Laboratory (SSDL) of the Atomic Energy Authority (ALA) of Sri Lanka provides path of workflow and information on laboratory operations, management and competence of staff that would assist the laboratory in continual improvement of its processes and meeting accreditation requirements in compliance with IS017025. Thus provision of customers' satisfied accredited dosimetry calibration services is needed for the country. The SSDL currently possesses a reference electrometer (PTW Unidos) with protection level ion- chambers (NE2575, 600cc ion-chamber and PTW - lOLt ion-chamber) and therapy level ion-chambers (NE2571, 0.6cc thimble ion-chamber). Also the laboratory is also having measuring standards (NE2570 electrometer with NE2575, 600cc ion-chamber and NE2571, 0.6cc thimble ion-chamber) . A gamma irradiator which contains two gamma sources (Co-60 and Cs-137) and a X-ray system with six ISO 4037 beam qualities (narrow spectrum of energy range: 33keV - 118keV) are available for protection level X-ray calibrations. Stability of the electrometers with Ion- chambers is performed with Sr-90 check sources, which are specially designed for each type of chambers in order to fix the set-up maintaining the same geometry for every measurement. An average of reading of ten consecutive measurements of which each measurement was made for 300s is taken for stability measurement. Each reading is corrected for ambient temperature and pressure. Acceptance of percentage deviation of stability results with respect to reference reading of respective chamber is ±1% for protection level and ± 0.5% for therapy level. All these equipments, when they are not in used are kept in a dry cabinet in order to control humidity. The SSDL of AEA has become a part of an international network of dosimetry laboratories established by the International Atomic Energy Agency (IAEA) and the World Health Organization (WHO

  13. Topics in radiation dosimetry radiation dosimetry

    1972-01-01

    Radiation Dosimetry, Supplement 1: Topics in Radiation Dosimetry covers instruments and techniques in dealing with special dosimetry problems. The book discusses thermoluminescence dosimetry in archeological dating; dosimetric applications of track etching; vacuum chambers of radiation measurement. The text also describes wall-less detectors in microdosimetry; dosimetry of low-energy X-rays; and the theory and general applicability of the gamma-ray theory of track effects to various systems. Dose equivalent determinations in neutron fields by means of moderator techniques; as well as developm

  14. Biological dosimetry - Dose estimation method using biomakers

    The individual radiation dose estimation is an important step in the radiation risk assessment. In case of radiation incident or radiation accident, sometime, physical dosimetry method can not be used for calculating the individual radiation dose, the other complement method such as biological dosimetry is very necessary. This method is based on the quantitative specific biomarkers induced by ionizing radiation, such as dicentric chromosomes, translocations, micronuclei... in human peripheral blood lymphocytes. The basis of the biological dosimetry method is the close relationship between the biomarkers and absorbed dose or dose rate; the effects of in vitro and in vivo are similar, so it is able to generate the calibration dose-effect curve in vitro for in vivo assessment. Possibilities and perspectives for performing biological dosimetry method in radiation protection area are presented in this report. (author)

  15. Accreditation to ISO 17025:2005 for the Radioactivity Metrology Group of the UK's National Physical Laboratory

    In the mid 1990s, the National Physical Laboratory (NPL) took the decision to seek external accreditation to the then UK national accreditation standard (M10, M10 supplement and M11) through the NPL's National Measurement Accreditation Service (NAMAS). This paper details the reasoning behind that initial decision and, in particular, how this impinged on the day-to-day activities of the NPL's Radioactivity Metrology Group (RMG). In the intervening decade, the accreditation standard has changed considerably; accreditation is now to the international standards ISO 9001:2000 (Quality Management Systems: Requirements) and ISO 17025:2005 (General Requirements for the Competence of Testing and Calibration Laboratories); accreditation is now carried out by a wholly separate successor organization to NAMAS, the United Kingdom Accreditation Service (UKAS). To meet the new accreditation requirements the RMG: realigned it's scope of work; streamlined and consolidated written procedures, references and appendices; centralized the collection of written procedures, and clarified the document identification system. Future developments will include efforts for RMG accreditation for conducting proficiency tests and providing reference materials. (author)

  16. Laboratory accreditation in developing economies

    Full text: Accreditation of laboratories has been practiced for well over one hundred years with the primary objective of seeking a formal recognition for the competence of a laboratory to perform specified tests or measurements. While first accreditation schemes intended initially to serve only the immediate needs of the body making the evaluation with the purpose of minimizing testing and inspection to be conducted by laboratories, third-party accreditation enables a laboratory to demonstrate its capability as well as availability of all necessary resources to undertake particular tests correctly and that is managed in such a way that it is likely to do this consistently, taking into consideration standards developed by national and international standards-setting bodies. The international standard ISO/IEC 17025 and laboratory accreditation are concerned with competence and quality management of laboratories only, thus requiring a single common set of criteria applicable to them. Quality assurance is therefore fully relevant to laboratories in general and analytical laboratories in particular; it should not be confused with the certification approach according to ISO/IEC 9000 family of standards, that is concerned with quality management applicable to any organization as a whole. The role of laboratory accreditation can be manifold, but in all cases the recipient of the test report needs to have confidence that the data in it is reliable, particularly if the test data is important in a decision-making process. As such, it offers a comprehensive way to ensure: - the availability of managerial and technical staff with the authority and resources needed; - the effectiveness of equipment management, traceability of measurement and safety procedures; - the performance of tests, taking into consideration laboratory accommodation and facilities as well as laboratory practices. The presentation will include also some practical aspects of quality management system

  17. Accreditation of occupational health services in Norway

    Lie, A.; Bjørnstad, O.

    2015-01-01

    Background In 2010, an accreditation system for occupational health services (OHS) in Norway was implemented. Aims To examine OHS experiences of the accreditation system in Norway 4 years after its implementation. Methods A web-based questionnaire was sent to all accredited OHS asking about their experiences with the accreditation system. Responses were compared with a similar survey conducted in 2011. Results The response rate was 76% (173/228). OHS reported that the most common changes they...

  18. Accreditation of Engineering Programs In The USA

    Jones, E. C.; Reyes-Guerra, David R.

    1989-01-01

    Accreditation is a way of assessing the quality of education. In the United States accreditation of engineering programs is carried out by volunteers, engineering educators and practitioners who evaluate programs against criteria developed by the profession. Universities voluntarily submit their engineering programs for professional accreditation. The process is supported by various professional engineering societies, the universities that request accreditation, the volunteers who carry out t...

  19. Feasibility of using neural networks to unfold the response of multi-element TLD for mixed field dosimetry

    Significant advances have been made in recent years to improve calibration methodology and dose calculation algorithm in the fields of TL dosimetry. This process was accelerated in the past decade particularly in the Republic of Korea by the need to meet mandatory national accreditation requirements. The objective of this study is to develop a new algorithm to replace the simplistic decision tree algorithms by the more sophisticated neural networks in hopes of achieving a higher degree of accuracy and precision in personnel dosimetry system. The original hypothesis of this work is that the spectral information of an X and γ-ray fields may be obtained by the analysis of the response of a multi-element system. In this study, a feed forward neural network using the error back-propagation method with Bayesian optimization was designed for the response unfolding procedure. The response functions of the single element to photons were calculated by application of a computational Monte-Carlo model for an energy range from 10 keV to 2 MeV with different spectral proportions. The training of the artificial neural network was based on the computation of responses of a four-element system for the back-propagation method. The validation of the proposed algorithm was investigated by unfolding the 10 computed responses for arbitrary mixed gamma fields and the spectra resulting from the unfolding procedure agree well with the original spectra. (author)

  20. Survey of international personnel radiation dosimetry programs

    In September of 1983, a mail survey was conducted to determine the status of external personnel gamma and neutron radiation dosimetry programs at international agencies. A total of 130 agencies participated in this study including military, regulatory, university, hospital, laboratory, and utility facilities. Information concerning basic dosimeter types, calibration sources, calibration phantoms, corrections to dosimeter responses, evaluating agencies, dose equivalent reporting conventions, ranges of typical or expected dose equivalents, and degree of satisfaction with existing systems was obtained for the gamma and neutron personnel monitoring programs at responding agencies. Results of this survey indicate that to provide the best possible occupational radiation monitoring programs and to improve dosimetry accuracy in performance studies, facility dosimetrists, regulatory and standards agencies, and research laboratories must act within their areas of responsibility to become familiar with their radiation monitoring systems, establish common reporting guidelines and performance standards, and provide opportunities for dosimetry testing and evaluation. 14 references, 10 tables

  1. 42 CFR 423.168 - Accreditation organizations.

    2010-10-01

    ... accreditation organization. (2) Within 30 days of a change in CMS requirements, submit the following to CMS— (i... an accreditation organization for a given standard under this part if the organization meets the... whenever it is considering granting an accreditation organization's application for approval. The...

  2. The Accreditation of Laboratories Proficiency and Safety

    2005-01-01

    @@ Recently, China National Accreditation Board for Laboratories (CNAL) has released CNAL/AC23:2004 Medical Laboratories: Accreditation Criteria For Quality and Proficiency, and meanwhile GB 19489 Laboratories: General Requirements For Biosafety and ISO 15190 Medical Laboratories-Requirements For Safetywill be adopted by CNAL as the accreditation criteria for laboratories safety.

  3. Personal dosimetry performance testing in the United States

    The basis for personal dosimetry performance testing in the United States is ANSI/HPS N13.11. Now in it's fourth edition, this standard has been in place since 1983. Testing under this standard is administered by the National Voluntary Laboratory Accreditation Program (NVLAP), and accreditation of dosimetry processors under this program is required by U.S. Nuclear Regulatory Commission (NRC) regulations. The U.S. Department of Energy (DOE) also maintains a testing program for its laboratories and contractors, administered by the Department of Energy Laboratory Accreditation Program (DOELAP). One of the goals of this current revision was the modification of ANSI/HPS N13.11 to allow acceptance by both testing programs in order to bring harmonization to U.S. personal dosemeter performance testing. The testing philosophy of ANSI/HPS N13.11 has always combined elements of type testing and routine performance testing and is thus different from the testing philosophy used in the rest of the world. In this paper, the history of performance testing in the U.S. is briefly reviewed. Also described is the revision that produced the fourth edition of this standard, which has taken place over the last three years (2005-2008) by a working group representing national standards laboratories, government laboratories, the military, dosimetry vendors, universities and the nuclear power industry. (author)

  4. Specialized Accreditation: College Library Responses.

    Frazer, Stuart

    1994-01-01

    Offers a detailed overview of accreditation standards, criteria, and procedures used by one specialized accreditor; and suggests ways to be prepared for site visits and reports. A directory of 73 specialized accreditors and a brief bibliography are appended. (18 references) (Author/SLW)

  5. The Accreditation-Eligibility Link.

    Levin, Nora Jean

    1981-01-01

    Public policy rests on the unreliable assumption that postsecondary education institutions and programs approved by nationally recognized private accrediting agencies are bona fide providers of educational services, worthy of students' time, effort, and money and of federal funds. Rather, federal fund eligibility should focus on measures of…

  6. College Student Services Accreditation Questionnaire.

    Cassel, Russell N.

    1979-01-01

    This questionnaire is intended for use as one aspect in accrediting the "Student Personnel Services" which an institution of higher learning provides for students. Areas in question include personal development, health fostering, vocational preparation, effective personalized learning, economic viability, transpersonal offerings, and satisfactory…

  7. Dosimetry of total body irradiation

    In the treatment of disseminated malignancies an improvement in the curability and reduction of complication rates require high precision total body irradiation (TBI) and correct reporting of relevant treatment parameters. Optimal TBI dosimetry is the basis. Radiooncological and radiobiological requirements as well as the special physical situation have to be considered. To review the efforts of medical physicists, highlights from TBI workshops and publications are summarized. Additionally, dosimetric data from 34 European radiooncological centres contributing to the recent ESTRO inquiry on TBI are analysed. The topics are: absorbed dose and dose monitor calibration, determination of absolute and relative doses, dose ratios, attenuation data and heterogeneity corrections; TBI dose calculation methods regarding patient position, beam incidence, body shape and thickness, lung size and density; methods of TBI treatment planning including calculated dose modification and of TBI quality assurance. In conclusion, the following recommendations can be given: TBI dosimetry shall be performed under TBI conditions, close to the real treatment situation. The absorbed dose to water must be determined. The dose monitor should be calibrated against dose measurements at the centre of a water equivalent phantom of TBI equivalent size and typical thickness. Photon fluence profiles have to be measured with small phantoms. Influences on the local dose must be investigated systematically. A reproducible AP/PA TBI technique should be used. The TBI dose shall be specified to mid-abdomen and reported in units of gray. The single and total dose and the dose rate to the lungs, the number of fractions and the treatment time schedule must be stated. In vivo dosimetry is required if non-reliable TBI techniques are used. An international TBI dosimetry intercomparison could assist these efforts to improve the treatment of acute leukaemia. (author). 89 refs, 3 figs, 13 tabs

  8. Accreditation to supervise research

    In this document the author reviews his works between 1995 and 2010. First, the development of a silicon pixel detector is detailed, the purpose of this detector was to improve the forward proton spectrometer of the H1 experiment at DESY. The works made to develop the reading circuits of the pixel detector are presented, particularly the design of the test bench for the testing of these circuits and the simulation of their behaviour in realistic environment. The second part describes the design of the front electronic for the data acquisition of the calorimeter detector of ATLAS (TileCal) and its testing system (MobiDICK). The software for the control system of the laser calibration of TileCal is detailed. The last part gives an account of the author's activities in the field of science popularization through the 'Cosmophone' and knowledge dissemination. The Cosmophone is a particle detector that turns the passage of particles into sounds in order to make the general public more aware of the presence of particles

  9. The Brazilian experience on the integrated authorization of individual monitoring systems and calibration laboratories of equipment used in radiation protection

    In Brazil, the National Commission for Nuclear Energy gives formal authorization of operation for Individual Monitoring Services and for Calibration Facilities for Equipment Used in Radiation Protection. The responsibility for recommending these authorizations has been delegated to the Institute for Radiation Protection and Dosimetry which, until 2005, had two separate committees operating in each area of authorization, namely IMS and calibration laboratories. Both committees had the responsibility of defining the requirements for authorization, auditing the laboratories, organizing inter-comparison exercises, certifying the heads of the laboratories and of recommending the authorization or cessation of laboratories activities to the direction of the institute. In the year 2005 a single integrated committee was formed to perform both kinds of authorization, which was named Committee for the Evaluation of Services of Essays and Calibration (CASEC). With a different philosophy in mind, this new group focuses only on the certification of compliance with the authorization regulation, leaving the definition of these rules to independent groups named technical chambers that should be formed by experts, who are not necessarily staff, according to specific needs. At present, CASEC is starting to require accreditation on ISO standard 17025 for both kinds of laboratories as a prerequisite for the authorization. This paper presents the difficulties faced during the process of transition from one system of authorization to the other, the present status of the system of individual monitoring systems and calibration facilities and results of inter-laboratory comparison exercises. (author)

  10. Perspective from a commercial supplier of dosimetry services

    The traditional radiation related industries in the United States have matured. The growth rates in the numbers of radiation workers have moderated and ALARA programs have favorably reduced many exposures. Dosimetry testing and accreditation by the National Bureau of Standards have identified those services possessing satisfactory dosimetry systems and technical competence. These developments have influenced the business perspectives. Combined with the overall renewed emphasis on competition and productivity in American business, many dosimetry services have become more aggressive in seeking new markets; residential radon measurements being most obvious. The potential size of these markets is making investments in technical research more attractive. In the past, most research funding was provided by the government. The renewed research interest by the private sector could stimulate the entry of new professionals into radiation measurement research. Research results have the potential for improving traditional services and expanding the applicability of certain measurement methods

  11. INPO accreditation - product definition for utility training

    As a part of its responsibility to promote training excellence, the Institute of Nuclear Power Operations (INPO) initiated an accreditation program in 1982 on behalf of its member utilities. The purpose of the accreditation program is to assist INPO members in developing and maintaining training programs that produce well-qualified, competent personnel to operate the nation's nuclear power plants. Accreditation formally recognizes nuclear utility training as meeting the INPO accreditation objectives and criteria for initial and continuing training programs for operations, maintenance, and technical personnel. The ultimate objective to be achieved by accreditation is to maintain high-quality training and enhance the professionalism of the personnel who operate the nuclear power plants. While initial accreditation represents recognition that quality training programs have been put in place at the nuclear power plants, the renewal of accreditation represents recognition that quality training programs have been put in place at the nuclear power plants, the renewal of accreditation will keep the training programs vital, effective, and up to high standards. The nuclear power industry has accepted the responsibility of striving for excellence in training its personnel to safely operate the power plants. The full use of accreditation and the accrediting process is an important means to fulfilling this responsibility

  12. Definition study of the project Dosimetry Brachytherapy

    The purpose of the research project Dosimetry Brachytherapy is the standardization of calibration methods and quality control procedures used for Brachytherapy sources. Proposals to develop measurement standards and methods for calibrating these sources are presented. Brachytherapy sources will be calibrated in terms of reference airkerma rate or in terms of absorbed dose in water. Therefore, in this project, special attention will be given to the in-phantom measurement method described by Meertens and the use of re-entrant ionisation chambers as transfer standards. In this report, a workplan and time schedule is included. (author). 19 refs.; 1 fig

  13. Secondary standard dosimetry laboratory at INFLPR

    Scarlat, F.; Minea, R.; Scarisoreanu, A.; Badita, E.; Sima, E.; Dumitrascu, M.; Stancu, E.; Vancea, C., E-mail: scarlat.f@gmail.com [National Institute for Laser, Plasma and Radiation Physics - INFLPR, Bucharest (Romania)

    2011-07-01

    National Institute for Laser, Plasma and Radiation Physics (INFLPR) has constructed a High Energy Secondary Standard Dosimetry Laboratory SSDL-STARDOOR - for performing dosimetric calibrations according to ISO IEC SR/EN 17025:2005 standards. This is outfitted with UNIDOS Secondary Standard Dosimeter from PTW (Freiburg Physikalisch-Technische Werksttaten) calibrated at the PTB-Braunschweig (German Federal Institute of Physics and Metrology). A radiation beam of the quality of Q used by our laboratory as calibration source are provided by INFLPR 7 MeV electron beam linear accelerator mounted in our facility. (author)

  14. Dosimetry for electron beam application

    This report describes two aspects of electron beam dosimetry, on one hand development of film dosimeters and measurements of their properties, and on the other hand development of calorimeters for calibration of routine dosimeters, e.g. thin films. Two types of radiochromic thin film dosimeters have been developed in this department, and the properties of these and commercially available dosimeters have been measured and found to be comparable. Calorimeters which are in use for routine measurements, are being investigated with reference to their application as standardizing instruments, and new calorimeters are being developed. (author)

  15. Breast dosimetry

    The estimation of the absorbed dose to the breast is an important part of the quality control of the mammographic examination. Knowledge of breast dose is essential for the design and performance assessment of mammographic imaging systems. This review gives a historical introduction to the measurement of breast dose. The mean glandular dose (MGD) is introduced as an appropriate measure of breast dose. MGD can be estimated from measurements of the incident air kerma at the surface of the breast and the application of an appropriate conversion factor. Methods of calculating and measuring this conversion factor are described and the results discussed. The incident air kerma itself may be measured for patients or for a test phantom simulating the breast. In each case the dose may be determined using TLD measurements, or known exposure parameters and measurements of tube output. The methodology appropriate to each case is considered and the results from sample surveys of breast dose are presented. Finally the various national protocols for breast dosimetry are compared

  16. Uncertainty in 3D gel dosimetry

    De Deene, Yves; Jirasek, Andrew

    2015-01-01

    Three-dimensional (3D) gel dosimetry has a unique role to play in safeguarding conformal radiotherapy treatments as the technique can cover the full treatment chain and provides the radiation oncologist with the integrated dose distribution in 3D. It can also be applied to benchmark new treatment strategies such as image guided and tracking radiotherapy techniques. A major obstacle that has hindered the wider dissemination of gel dosimetry in radiotherapy centres is a lack of confidence in the reliability of the measured dose distribution. Uncertainties in 3D dosimeters are attributed to both dosimeter properties and scanning performance. In polymer gel dosimetry with MRI readout, discrepancies in dose response of large polymer gel dosimeters versus small calibration phantoms have been reported which can lead to significant inaccuracies in the dose maps. The sources of error in polymer gel dosimetry with MRI readout are well understood and it has been demonstrated that with a carefully designed scanning protocol, the overall uncertainty in absolute dose that can currently be obtained falls within 5% on an individual voxel basis, for a minimum voxel size of 5 mm3. However, several research groups have chosen to use polymer gel dosimetry in a relative manner by normalizing the dose distribution towards an internal reference dose within the gel dosimeter phantom. 3D dosimetry with optical scanning has also been mostly applied in a relative way, although in principle absolute calibration is possible. As the optical absorption in 3D dosimeters is less dependent on temperature it can be expected that the achievable accuracy is higher with optical CT. The precision in optical scanning of 3D dosimeters depends to a large extend on the performance of the detector. 3D dosimetry with X-ray CT readout is a low contrast imaging modality for polymer gel dosimetry. Sources of error in x-ray CT polymer gel dosimetry (XCT) are currently under investigation and include inherent

  17. Neutron dosimetry - A review

    This review summarizes information on the following subjects: (1) physical processes of importance in neutron dosimetry; (2) biological effects of neutrons; (3) neutron sources; and (4) instruments and methods used in neutron dosimetry. Also, possible improvements in dosimetry instrumentation are outlined and discussed. (author)

  18. Accreditation of undergraduate and graduate medical education

    Davis, Deborah J; Ringsted, Charlotte

    2006-01-01

    Accreditation organizations such as the Liaison Committee for Medical Education (LCME), the Royal College of Physicians and Surgeons of Canada (RCPSC), and the Accreditation Council for Graduate Medical Education (ACGME) are charged with the difficult task of evaluating the educational quality of...... not at all clear. As medical education moves toward outcome-based education related to a broad and context-based concept of competence, the accreditation paradigm should change accordingly. Udgivelsesdato: 2006-Aug...... medical education programs in North America. Traditionally accreditation includes a more quantitative rather than qualitative judgment of the educational facilities, resources and teaching provided by the programs. The focus is on the educational process but the contributions of these to the outcomes are......Accreditation organizations such as the Liaison Committee for Medical Education (LCME), the Royal College of Physicians and Surgeons of Canada (RCPSC), and the Accreditation Council for Graduate Medical Education (ACGME) are charged with the difficult task of evaluating the educational quality of...

  19. Early experiences of accredited clinical informatics fellowships.

    Longhurst, Christopher A; Pageler, Natalie M; Palma, Jonathan P; Finnell, John T; Levy, Bruce P; Yackel, Thomas R; Mohan, Vishnu; Hersh, William R

    2016-07-01

    Since the launch of the clinical informatics subspecialty for physicians in 2013, over 1100 physicians have used the practice and education pathways to become board-certified in clinical informatics. Starting in 2018, only physicians who have completed a 2-year clinical informatics fellowship program accredited by the Accreditation Council on Graduate Medical Education will be eligible to take the board exam. The purpose of this viewpoint piece is to describe the collective experience of the first four programs accredited by the Accreditation Council on Graduate Medical Education and to share lessons learned in developing new fellowship programs in this novel medical subspecialty. PMID:27206458

  20. 75 FR 59605 - National Veterinary Accreditation Program; Currently Accredited Veterinarians Performing...

    2010-09-28

    ... United States and internationally. On December 9, 2009 (74 FR 64998-65013, Docket No. APHIS-2006- 0093... Health Inspection Service 9 CFR Part 161 RIN 0579-AC04 National Veterinary Accreditation Program... National Veterinary Accreditation Program (NVAP) may continue to perform accredited duties and to elect...

  1. Engineering Accreditation in China: The Progress and Development of China's Engineering Accreditation

    Jiaju, Bi

    2009-01-01

    Among engineering degree programs at the bachelor's level in China, civil engineering was the first one accredited in accordance with a professional programmatic accreditation system comparable to that of international practice. Launched in 1994, the accreditation of civil engineering aimed high and toward international standards and featured the…

  2. A Threat to Accreditation: Defamation Judgment against an Accreditation Team Member.

    Flygare, Thomas J.

    1980-01-01

    Delaware Law School founder Alfred Avins successfully sued accreditation team member James White for defamation as a result of comments made in 1974 and 1975. An appeals brief claims Avins was a "public figure," that he consented to accreditation, and that the accreditation process deserves court protection against such suits. (PGD)

  3. Software for evaluation of EPR-dosimetry performance

    Electron paramagnetic resonance (EPR) with tooth enamel is a method extensively used for retrospective external dosimetry. Different research groups apply different equipment, sample preparation procedures and spectrum processing algorithms for EPR dosimetry. A uniform algorithm for description and comparison of performances was designed and implemented in a new computer code. The aim of the paper is to introduce the new software 'EPR-dosimetry performance'. The computer code is a user-friendly tool for providing a full description of method-specific capabilities of EPR tooth dosimetry, from metrological characteristics to practical limitations in applications. The software designed for scientists and engineers has several applications, including support of method calibration by evaluation of calibration parameters, evaluation of critical value and detection limit for registration of radiation-induced signal amplitude, estimation of critical value and detection limit for dose evaluation, estimation of minimal detectable value for anthropogenic dose assessment and description of method uncertainty. (authors)

  4. Dosimetry on the radiological risks prevention in radiotherapy

    Dosimetry in its various forms plays a determining role on the radiological risks prevention in radiotherapy. To prove this in this paper is shown an analysis based on the risk matrix method, how the dosimetry can influence in each stages of a radiotherapy service; installation and acceptance, operation, maintenance and calibration. For each one of these stages the role that can play is analyzed as either the initiating event of a radiological accident or limiting barrier of these events of the dosimetric processes used for the individual dosimetry, the area monitoring, fixed or portable, for radiation beam dosimetry and of the patients for a radiotherapy service with cobalt-therapy equipment. The result of the study shows that the application of a prospective approach in the role evaluation of dosimetry in the prevention and mitigation of the consequences of a radiological accident in radiotherapy is crucial and should be subject to permanent evaluation at each development stage of these services. (author)

  5. Instrumentation for the individual dosimetry of workers

    Thévenin, J C

    2003-01-01

    The control of the radiation dose exposure of workers and personnel exposed to ionizing radiations (nuclear industry, nuclear medicine, army, university laboratories etc..) is ensured by individual dosemeters. This dosimetry is mandatory for all workers susceptible to be exposed to more than 30% of the regulatory dose limit. dosemeters are worn on the chest and in some particular cases, on the finger (dosemeter rings) or on the wrist. Passive dosemeters allow to measure the dose a posteriori, while electronic dosemeters allow a direct reading and recording of the dose. This article presents successively: 1 - the general principles of individual dosimetry: situations of exposure, radiation detection, operational data, standardization, calibration and quality assurance, measurement uncertainties; 2 - goals and regulatory framework of individual dosimetry: regulation and recommendations, optimization, respect of dose limits, accidental situations; 3 - passive dosemeters: film, thermoluminescent, radio-photolumin...

  6. Performance testing of UK personal dosimetry laboratories

    Marshall, T O

    1985-01-01

    The proposed Ionising Radiations Regulations will require all UK personal dosimetry laboratories that monitor classified personnel to be approved for personal dosimetry by the Health and Safety Executive. It is suggested that these approvals should be based on general and supplementary criteria published by the British Calibration Service (BCS) for laboratory approval for the provision of personal dosimetry services. These criteria specify certain qualitative requirements and also indicate the need for regular tests of performance to be carried out to ensure constancy of dosimetric standards. This report concerns the latter. The status of the BCS criteria is discussed and the need for additional documents to cover new techniques and some modifications to existing documents is indicated. A means is described by which the technical performance of laboratories, concerned with personal monitoring for external radiations, can be assessed, both initially and ongoing. The costs to establish the scheme and operate it...

  7. Performance testing of UK personal dosimetry laboratories

    The proposed Ionising Radiations Regulations will require all UK personal dosimetry laboratories that monitor classified personnel to be approved for personal dosimetry by the Health and Safety Executive. It is suggested that these approvals should be based on general and supplementary criteria published by the British Calibration Service (BCS) for laboratory approval for the provision of personal dosimetry services. These criteria specify certain qualitative requirements and also indicate the need for regular tests of performance to be carried out to ensure constancy of dosimetric standards. This report concerns the latter. The status of the BCS criteria is discussed and the need for additional documents to cover new techniques and some modifications to existing documents is indicated. A means is described by which the technical performance of laboratories, concerned with personal monitoring for external radiations, can be assessed, both initially and ongoing. The costs to establish the scheme and operate it are also estimated. (author)

  8. General guidance for laboratories providing personal dosimetry services

    This guidance is recommended to all dosimetry services in the interests of good radiation protection practice. For dosimetry services who seek approval under the Ionising Radiation Regulations 1985, the Health and Safety Executive (HSE) would invoke compliance with this guidance, in broad terms, as well as other published guidance. The recommendations include sections concerning laboratory organizations and staff, documentation of procedures, laboratory accommodation and services, equipment, calibration and traceability, housekeeping, dosimetric capability, laboratory records. (Author)

  9. Lyoluminescence dosimetry of the radiation in industrial doses

    The γ-rays lyoluminescence (LL) dosimetry study is presented. The basic principles involved, both in the method and radiation dosimetry, the equivalence between water and lyoluminescent materials, apparatus, irradiation technique and calibration method are discussed. The LL response dependence with environmental conditions are presented. These were temperature, humidity, storage time and the dependence on dissolved mass. A pre-reading thermal treatment was developed to overcome previous difficulties. The developed technique was applied to dose intercomparisons. (M.A.C.)

  10. HSE performance tests for dosimetry services

    In the United Kingdom a dosimetry service that measures and assesses whole-body or part-body doses arising from external radiation must successfully complete a performance test. Results of the performance tests for routine whole-body, routine extremity/skin and special accident dosimetry, carried out over the past six years by the AEA Technology Calibration Service at Winfrith, and DRaStaC, the AWE Calibration Service at Aldermaston, are presented. The test involves irradiating groups of dosemeters to known doses of gamma radiation and determining the bias and relative standard deviations for each dose group. The results are compared with the pass criteria specified by the UK Health and Safety Executive. For routine whole-body dosimetry, both the film badge and thermoluminescent dosemeter (TLD) perform adequately for irradiations between 0.6 and 30 mSv. For higher doses up to 250 mSv, where the slow emulsion of the film is used, the film badge shows poorer performance with a tendency to overestimate the dose. For routine extremity/skin dosimetry there is a wider spread of relative standard deviation results than is seen for routine whole-body dosimetry. This is to be expected since the results will include dosemeters that are based on 'disposable' TLDs and ones based on lithium fluoride powder in sachets. For special accident dosimetry the dosemeters are tested between 0.26 and 6 Gy. For the highest dose group the film badge invariably underestimates the true dose, whereas the TLD has a tendency to overestimate it. (author)