Track-etched detectors are commonly used also for radiation monitoring onboard International Space Station. To be registered in track-etched detectors, the particle needs to meet several criteria-it must have linear energy transfer above the detection threshold and strike the detector's surface under an angle higher than the so-called critical angle. Linear energy transfer is then estimated from calibration curve from the etch rate ratio V that is calculated from parameters of individual tracks appearing on the detector's surface after chemical etching. It has been observed that V can depend on the incident angle and this dependence can vary for different detector materials, etching and evaluating conditions. To investigate angular dependence, detectors (Harzlas TD-1) were irradiated at HIMAC by several ions under angles from 0° to 90°. The correction accounting not only for critical angle but also for dependence of V on the incident angle is introduced and applied to spectra measured onboard International Space Station.
- MeSH
- dávka záření MeSH
- ionty MeSH
- kalibrace MeSH
- kosmická loď * MeSH
- kosmické záření MeSH
- kosmický let přístrojové vybavení MeSH
- lineární přenos energie MeSH
- monitorování radiace přístrojové vybavení metody MeSH
- termoluminiscenční dozimetrie přístrojové vybavení metody MeSH
- těžké ionty * MeSH
- Publikační typ
- časopisecké články MeSH
Proton beam therapy has advantages in comparison to conventional photon radiotherapy due to the physical properties of proton beams (e.g. sharp distal fall off, adjustable range and modulation). In proton therapy, there is the possibility of sparing healthy tissue close to the target volume. This is especially important when tumours are located next to critical organs and while treating cancer in paediatric patients. On the other hand, the interactions of protons with matter result in the production of secondary radiation, mostly neutrons and gamma radiation, which deposit their energy at a distance from the target. The aim of this study was to compare the response of different passive dosimetry systems in mixed radiation field induced by proton pencil beam inside anthropomorphic phantoms representing 5 and 10 years old children. Doses were measured in different organs with thermoluminescent (MTS-7, MTS-6 and MCP-N), radiophotoluminescent (GD-352 M and GD-302M), bubble and poly-allyl-diglycol carbonate (PADC) track detectors. Results show that RPL detectors are the less sensitive for neutrons than LiF TLDs and can be applied for in-phantom dosimetry of gamma component. Neutron doses determined using track detectors, bubble detectors and pairs of MTS-7/MTS-6 are consistent within the uncertainty range. This is the first study dealing with measurements on child anthropomorphic phantoms irradiated by a pencil scanning beam technique.
- MeSH
- algoritmy MeSH
- antropometrie MeSH
- celková dávka radioterapie MeSH
- dávka záření MeSH
- design vybavení MeSH
- dítě MeSH
- fantomy radiodiagnostické * MeSH
- ionizující záření MeSH
- lidé MeSH
- metoda Monte Carlo MeSH
- neutrony MeSH
- předškolní dítě MeSH
- protonová terapie přístrojové vybavení MeSH
- protony * MeSH
- radioisotopová scintigrafie MeSH
- radiometrie přístrojové vybavení MeSH
- termoluminiscenční dozimetrie přístrojové vybavení MeSH
- záření gama terapeutické užití MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- předškolní dítě MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
As workers in interventional radiology belong to one of the most occupationally exposed groups, methods for sufficiently accurate quantification of their external exposure are sought. The objective of the authors' experiment was to investigate the relations between eye lens dose and Hp(10), Hp(3) or Hp(0.07) values measured with a conventional whole-body personal thermoluminescence dosemeter (TLD). Conditions of occupational exposure during common interventional procedures were simulated in laboratory. An anthropomorphic phantom represented a physician. The TLDs were fixed to the phantom in different locations that are common for purposes of personal dosimetry. In order to monitor the dose at the eye lens level during the exposures, a special thermoluminescence eye dosemeter was fixed to the phantom's temple. Correlations between doses measured with the whole-body and the eye dosemeters were found. There are indications that personnel in interventional radiology do not need to be unconditionally equipped with additional eye dosemeters, especially if an appropriate whole-body dosimetry system has been already put into practice.
- MeSH
- celotělové počítání MeSH
- dávka záření * MeSH
- fantomy radiodiagnostické MeSH
- intervenční radiologie metody MeSH
- kalibrace MeSH
- lidé MeSH
- monitorování radiace metody MeSH
- ochranné prostředky očí MeSH
- oční čočka účinky záření MeSH
- operační sály MeSH
- počítačová simulace MeSH
- pracovní expozice analýza prevence a kontrola MeSH
- radiační ochrana metody MeSH
- termoluminiscenční dozimetrie přístrojové vybavení metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
UNLABELLED: The International Atomic Energy Agency (IAEA) has a long tradition of supporting development of methodologies for national networks providing quality audits in radiotherapy. A series of co-ordinated research projects (CRPs) has been conducted by the IAEA since 1995 assisting national external audit groups developing national audit programs. The CRP 'Development of Quality Audits for Radiotherapy Dosimetry for Complex Treatment Techniques' was conducted in 2009-2012 as an extension of previously developed audit programs. MATERIAL AND METHODS: The CRP work described in this paper focused on developing and testing two steps of dosimetry audit: verification of heterogeneity corrections, and treatment planning system (TPS) modeling of small MLC fields, which are important for the initial stages of complex radiation treatments, such as IMRT. The project involved development of a new solid slab phantom with heterogeneities containing special measurement inserts for thermoluminescent dosimeters (TLD) and radiochromic films. The phantom and the audit methodology has been developed at the IAEA and tested in multi-center studies involving the CRP participants. RESULTS: The results of multi-center testing of methodology for two steps of dosimetry audit show that the design of audit procedures is adequate and the methodology is feasible for meeting the audit objectives. A total of 97% TLD results in heterogeneity situations obtained in the study were within 3% and all results within 5% agreement with the TPS predicted doses. In contrast, only 64% small beam profiles were within 3 mm agreement between the TPS calculated and film measured doses. Film dosimetry results have highlighted some limitations in TPS modeling of small beam profiles in the direction of MLC leave movements. DISCUSSION: Through multi-center testing, any challenges or difficulties in the proposed audit methodology were identified, and the methodology improved. Using the experience of these studies, the participants could incorporate the auditing procedures in their national programs.
- MeSH
- dozimetry MeSH
- fantomy radiodiagnostické MeSH
- lidé MeSH
- mezinárodní agentury MeSH
- plánování radioterapie pomocí počítače metody normy MeSH
- radiometrie přístrojové vybavení metody normy MeSH
- řízení kvality MeSH
- termoluminiscenční dozimetrie přístrojové vybavení metody normy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
Dose delivered outside the proton field during radiotherapy can potentially lead to secondary cancer development. Measurements with a 170-MeV proton beam were performed with passive detectors (track etched detectors and thermoluminescence dosemeters) in three different depths along the Bragg curve. The measurement showed an uneven decrease of the dose outside of the beam field with local enhancements. The major contribution to the delivered dose is due to high-energy protons with linear energy transfer (LET) up to 10 keV µm(-1). However, both measurement and preliminary Monte Carlo calculation also confirmed the presence of particles with higher LET.
- MeSH
- celková dávka radioterapie * MeSH
- design vybavení MeSH
- fantomy radiodiagnostické MeSH
- lidé MeSH
- lineární přenos energie MeSH
- metoda Monte Carlo MeSH
- neutrony MeSH
- plánování radioterapie pomocí počítače MeSH
- polymethylmethakrylát chemie MeSH
- protonová terapie škodlivé účinky MeSH
- protony * MeSH
- radiometrie přístrojové vybavení metody MeSH
- radioterapie škodlivé účinky MeSH
- reprodukovatelnost výsledků MeSH
- termoluminiscenční dozimetrie přístrojové vybavení metody MeSH
- vysokoenergetická radioterapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Rusko MeSH
State-of-the-art laser systems are able to generate ionising radiation of significantly high energies by focusing ultra-short and intense pulses onto targets. Thus, measures ensuring the radiation protection of both working personnel and the general public are required. However, commercially available dosemeters are primarily designed for measurement in continuous fields. Therefore, it is important to explore their response to very short pulses. In this study, the responses of dosemeters in a radiation field generated by iodine high-power and Ti:Sapphire laser systems are examined in proton and electron acceleration experiments. Within these experiments, electron bunches of femtosecond pulse duration and 100-MeV energy and proton bunches with sub-nanosecond pulse duration and energy of several megaelectronvolts were generated in single-shot regimes. Responses of typical detectors (TLD, films and electronic personal dosemeter) were analysed and compared. Further, a first attempt was carried out to characterise the radiation field generated by TW-class laser systems.
- MeSH
- anizotropie MeSH
- dávka záření MeSH
- design vybavení MeSH
- elektronika MeSH
- elektrony MeSH
- ionizující záření MeSH
- jod MeSH
- křemík MeSH
- lasery * MeSH
- lidé MeSH
- oxid hlinitý chemie MeSH
- pracovní expozice analýza prevence a kontrola MeSH
- protony MeSH
- radiační ochrana přístrojové vybavení MeSH
- radiometrie přístrojové vybavení metody MeSH
- termoluminiscenční dozimetrie přístrojové vybavení metody MeSH
- titan chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Gamma dose and thermal neutron fluence in a phantom exposed to an epithermal neutron beam for boron neutron capture therapy (BNCT) can be measured by means of a single thermoluminescence dosemeter (TLD-700). The method exploits the shape of the glow curve (GC) and requires the gamma-calibration GC (to obtain gamma dose) and the thermal-neutron-calibration GC (to obtain neutron fluence). The method is applicable for BNCT dosimetry in case of epithermal neutron beams from a reactor because, in most irradiation configurations, thermal neutrons give a not negligible contribution to the TLD-700 GC. The thermal neutron calibration is not simple, because of the impossibility of having thermal neutron fields without gamma contamination, but a calibration method is here proposed, strictly bound to the method itself of dose separation.
- MeSH
- celková dávka radioterapie MeSH
- fantomy radiodiagnostické MeSH
- fluoridy MeSH
- fotony MeSH
- kalibrace MeSH
- lidé MeSH
- nádory radioterapie MeSH
- neutrony MeSH
- plánování radioterapie pomocí počítače MeSH
- reprodukovatelnost výsledků MeSH
- sloučeniny lithia MeSH
- terapie metodou neutronového záchytu (bor-10) metody MeSH
- termoluminiscenční dozimetrie přístrojové vybavení metody MeSH
- záření gama * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The paper discusses the situation in the Czech Republic regarding past and present uranium mining activities with emphasis on the evaluation of the exposure of underground miners in the Rožná Uranium Mine, which is currently the only active mine in the country and practically in the entire European Union. The total effective dose has been summarised taking into account all three major components, namely radon short-lived decay products, long-lived alpha emitters in ore dust and penetrating external gamma radiation. The average and maximum values of the effective dose as well as the collective effective dose of underground miners are also presented. The purpose of the paper is to document the miners' exposures during a period of 6 years in a uranium mine where conditions including the ore grade and methods of mining showed recently some changes that may affect the individual components of the total effective dose.
- MeSH
- dávka záření MeSH
- dceřiné produkty radonu MeSH
- hornictví MeSH
- lidé MeSH
- monitorování radiace přístrojové vybavení metody MeSH
- pracovní expozice prevence a kontrola MeSH
- radiační ochrana přístrojové vybavení metody MeSH
- radioaktivní látky znečišťující vzduch MeSH
- radiometrie přístrojové vybavení metody MeSH
- radon MeSH
- termoluminiscenční dozimetrie přístrojové vybavení MeSH
- uran analýza MeSH
- záření gama MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
The National Radiation Protection Institute in Prague is about to use a commercially available multi-element whole-body thermoluminescence dosimeter for its radiation personnel. During the phase of practical verification of the method, the dosimeter was tested, among others, in mixed neutron-photon fields in the area of interim storages for spent nuclear fuel of the Czech nuclear power plant Dukovany. The testing was made with the intention to get information about accuracy of H(p)(10) determination for cases when no site-specific calibration is available or neutron spectra are not known. The measured photon and neutron personal dose equivalents were evaluated and discussed in relation to results obtained by survey meters and neutron spectra measured before.
- MeSH
- ambulantní monitorování přístrojové vybavení MeSH
- analýza selhání vybavení MeSH
- design vybavení MeSH
- jaderná energie MeSH
- neutrony MeSH
- radioaktivní odpad analýza MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- termoluminiscenční dozimetrie přístrojové vybavení MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
