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  1. Article ; Online: Spectrum averaged cross section measurements of lutetium using standard

    Schulc, Martin / Košťál, Michal / Czakoj, Tomáš / Novák, Evžen / Šimon, Jan / Hynková, Nella / Capote, Roberto

    Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine

    2022  Volume 188, Page(s) 110378

    Abstract: The spectrum averaged cross section (SACS) in a standard neutron field is a preferable tool for cross section validation. The presented work uses only neutron standard, i.e., ...

    Abstract The spectrum averaged cross section (SACS) in a standard neutron field is a preferable tool for cross section validation. The presented work uses only neutron standard, i.e.,
    MeSH term(s) Lutetium/chemistry ; Models, Theoretical ; Neutrons ; Radioisotopes/chemistry
    Chemical Substances Radioisotopes ; Lutetium (5H0DOZ21UJ)
    Language English
    Publishing date 2022-07-12
    Publishing country England
    Document type Journal Article
    ZDB-ID 1142596-9
    ISSN 1872-9800 ; 0883-2889 ; 0969-8043
    ISSN (online) 1872-9800
    ISSN 0883-2889 ; 0969-8043
    DOI 10.1016/j.apradiso.2022.110378
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Book ; Online: The effect of heavy reflector on neutronic parameters of core

    Košťál, Michal / Losa, Evžen / Czakoj, Tomáš / Schulc, Martin / Šimon, Jan / Juříček, Vlastimil / Rypar, Vojtěch / Ulmanová, Jana / Trkov, Andrej / Capote, Roberto

    2023  

    Abstract: The reactor baffle is an important component of a nuclear reactor that fixes the location of the fuel assembly in the reactor core. The main types of baffles are called light or heavy. The light baffle has mostly the form of steel plates with outer space ...

    Abstract The reactor baffle is an important component of a nuclear reactor that fixes the location of the fuel assembly in the reactor core. The main types of baffles are called light or heavy. The light baffle has mostly the form of steel plates with outer space filled by water, and the heavy baffle is mostly a forged steel element. Both concepts have advantages as well as disadvantages. In the case of the light baffle, one does not need to solve the issue of void swelling, but the neutron economy is not ideal, while the heavy baffle has a good neutron economy, but void swelling is an issue. This paper deals with the effect of the heavy VVER-1000 baffle on criticality. Criticality was measured using a well-defined core composed of 6 fuel assemblies moved to a simulator of the VVER-1000 internals, which is located at the LR-0 reactor. The experiments confirm the fact that the water filling the cooling channels in the baffle has a strong neutron absorbing effect. The keff calculated using the ENDF/B-VIII.0 library significantly underpredicts the experiment, whereas calculations using a new evaluation of 56Fe by the IAEA (INDEN collaboration) give a better agreement. Generally, the presented results are suitable for validation of iron cross sections.
    Keywords Physics - Instrumentation and Detectors
    Subject code 660
    Publishing date 2023-06-05
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Validation of selected (n,2n) dosimetry reactions in IRDFF-1.05 library.

    Schulc, Martin / Košťál, Michal / Capote, Roberto / Novák, Evžen / Šimon, Jan / Burianová, Nicola / Wallner, Anton

    Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine

    2018  Volume 143, Page(s) 132–140

    Abstract: Spectrum-averaged cross sections (SACS) have been measured in the ... ...

    Abstract Spectrum-averaged cross sections (SACS) have been measured in the reference
    Language English
    Publishing date 2018-11-02
    Publishing country England
    Document type Journal Article
    ZDB-ID 1142596-9
    ISSN 1872-9800 ; 0883-2889 ; 0969-8043
    ISSN (online) 1872-9800
    ISSN 0883-2889 ; 0969-8043
    DOI 10.1016/j.apradiso.2018.10.027
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Book ; Online: Impact of Reactor Neutron Spectrum on Measured Spectrum Averaged Cross Sections

    Kostal, Michal / Losa, Evzen / Simakov, Stanislav / Schulc, Martin / Simon, Jan / Rypar, Vojtech / Mareček, Martin / Uhlíř, Jan / Czakoj, Tomáš / Trkov, Andrej / Capote, Roberto

    2023  

    Abstract: The cross section averaged over 235U thermal-neutron induced fission spectrum is a fundamental quantity that can be used in evaluation and validation of nuclear data. Many experiments focused on the determination of Spectrum Averaged Cross Sections (SACS) ...

    Abstract The cross section averaged over 235U thermal-neutron induced fission spectrum is a fundamental quantity that can be used in evaluation and validation of nuclear data. Many experiments focused on the determination of Spectrum Averaged Cross Sections (SACS) in 235U(nth,f). Prompt Fission Neutron Spectrum (PFNS) in light water reactors using enriched uranium fuel. In these reactors, there is already some amount of water moderator between the uranium fuel and the irradiated sample. Due to the decrease of hydrogen cross-section with neutron energy, the high energy tail of the reactor spectrum in cores with water moderator may be harder than the pure PFNS. This paper aims to compare the shape of the actual reactor spectrum in various core positions of a research light-water reactor differing each from other by the effective water thickness. The spectrum shape is determined both by calculations and experimentally using various high energy threshold reactions. The impact of the photo-nuclear reactions ({\gamma},n) competing with (n,2n) in production of the same residual nucleus was shown to be less than a percent for most of studied dosimeters. An important exception was found for 197Au(n,2n) 196Au dosimeter irradiated in the outcore channel where a notable photo-neutron contribution to the production of 196Au is caused by the neutron production from the high energy {\gamma}-rays from thermal-neutron capture in 54Fe. The corresponding ENDF/B-VIII.0 data turned out to underestimate such {\gamma}-yield by 40% in comparison with ENDF/B-VI.8. This has improved but however not resolved the disagreement between our measurement and calculations. The remaining deficiency was attributed to the underestimation of the evaluated cross section IAEA/PD-2019 for the 197Au({\gamma},n) cross section near the reaction threshold. The later was confirmed by comparison with existing measured data.
    Keywords Nuclear Experiment
    Subject code 660
    Publishing date 2023-06-05
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: A dispersive optical model potential for nucleon induced reactions on 238U and 232Th nuclei with full coupling

    Chiba Satoshi / Capote Roberto / Soukhovitskiĩ EfremS. / Manuel Quesada José

    EPJ Web of Conferences, Vol 42, p

    2013  Volume 02005

    Abstract: A dispersive coupled-channel optical model potential (DCCOMP) that couples the ground-state rotational and low-lying vibrational bands of 238U and 232Th nuclei is studied. The derived DCCOMP couples almost all excited levels below 1 MeV of excitation ... ...

    Abstract A dispersive coupled-channel optical model potential (DCCOMP) that couples the ground-state rotational and low-lying vibrational bands of 238U and 232Th nuclei is studied. The derived DCCOMP couples almost all excited levels below 1 MeV of excitation energy of the corresponding even-even actinides. The ground state, octupole, beta, gamma, and non-axial bands are coupled. The first two isobar analogue states (IAS) populated in the quasi-elastic (p,n) reaction are also coupled in the proton induced calculation, making the potential approximately Lane consistent. The coupled-channel potential is based on a soft-rotor description of the target nucleus structure, where dynamic vibrations are considered as perturbations of the rigid rotor underlying structure. Matrix elements required to use the proposed structure model in Tamura coupled-channel scheme are derived. Calculated ratio R(U238/Th232) of the total cross-section difference to the averaged σT for 238U and 232Th nuclei is shown to be in excellent agreement with measured data.
    Keywords Physics ; QC1-999 ; Science ; Q ; DOAJ:Physics (General) ; DOAJ:Physics and Astronomy
    Subject code 541
    Language English
    Publishing date 2013-03-01T00:00:00Z
    Publisher EDP Sciences
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Testing of various neutron filters in reference neutron field in LR-0 reactor for nuclear data validation and verification.

    Košťál, Michal / Losa, Evžen / Schulc, Martin / Czakoj, Tomáš / Peltan, Tomáš / Šimon, Jan / Juříček, Vlastimil / Rypar, Vojtěch / Thiollay, Nicolas / Destouches, Christophe / Radulović, Vladimir / Trkov, Andrej / Capote, Roberto

    Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine

    2020  Volume 169, Page(s) 109566

    Abstract: Neutron activation analysis is the reference method used for offline determination of the neutron flux density in defined positions. It can be used in the nuclear energy industry-as well as in medical- or space applications. For accurate neutron flux ... ...

    Abstract Neutron activation analysis is the reference method used for offline determination of the neutron flux density in defined positions. It can be used in the nuclear energy industry-as well as in medical- or space applications. For accurate neutron flux evaluation, well-known and reliable cross sections are needed. In the thermal and fast energy region, many reliable monitoring reactions exists, however, in case of the epithermal and intermediate energy region, there are practically no dosimetry nuclear reactions sensitive specifically in this energy range. Due to this fact, both new data are being measured and methodologies are under development to describe and test this energy region. It was found that various neutron filters can be used to cut parts of neutron spectra and thus methodology based on spectrum filtering could potentially be employed to survey cross sections of interest. It this paper, the use of 3 different filters - B
    Language English
    Publishing date 2020-12-24
    Publishing country England
    Document type Journal Article
    ZDB-ID 1142596-9
    ISSN 1872-9800 ; 0883-2889 ; 0969-8043
    ISSN (online) 1872-9800
    ISSN 0883-2889 ; 0969-8043
    DOI 10.1016/j.apradiso.2020.109566
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: An implementation to read and write IAEA phase-space files in GEANT4-based simulations.

    Cortés-Giraldo, Miguel Antonio / Quesada, José Manuel / Gallardo, María Isabel / Capote, Roberto

    International journal of radiation biology

    2012  Volume 88, Issue 1-2, Page(s) 200–208

    Abstract: Purpose: To develop a stand-alone code to make any application coded with the GEANT4 (GEometry ANd Tracking, version 4) toolkit capable of reading and writing phase-space (phsp) files in the format created by the IAEA (International Atomic Energy Agency) ...

    Abstract Purpose: To develop a stand-alone code to make any application coded with the GEANT4 (GEometry ANd Tracking, version 4) toolkit capable of reading and writing phase-space (phsp) files in the format created by the IAEA (International Atomic Energy Agency), so that the exchange of phsp files between other validated Monte Carlo (MC) codes and GEANT4 is possible.
    Methods: We present a stand-alone code, written in C++ object-oriented language, developed in a way that ensures the compatibility with future versions of the IAEA phsp format. The aim of the reader part is to get the information from a given IAEA phsp file and create the primary particles in a GEANT4 user application. On the other hand, the writer part of the code is the responsible for writing the IAEA phsp files during a run of the GEANT4 application.
    Results: A testing simulation was written with GEANT4 to verify the performance of this code, with satisfactory results. An example of use in a GEANT4 application which simulates the treatment head of a radiotherapy linear electron accelerator (linac) is also shown, comparing dose calculations with experimental data.
    Conclusions: This stand-alone package, which can be used in any GEANT4 application, allows the exchange of validated phsp files between different MC codes and the use of phsp data from many different accelerators and fields in dosimetry studies. Furthermore, it also offers additional utilities of interest in medical applications.
    MeSH term(s) Databases, Factual ; International Agencies ; Monte Carlo Method ; Photons/therapeutic use ; Reproducibility of Results ; User-Computer Interface
    Language English
    Publishing date 2012-01
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 3065-x
    ISSN 1362-3095 ; 0020-7616 ; 0955-3002
    ISSN (online) 1362-3095
    ISSN 0020-7616 ; 0955-3002
    DOI 10.3109/09553002.2011.627977
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article: An EGSnrc Monte Carlo study of the microionization chamber for reference dosimetry of narrow irregular IMRT beamlets.

    Capote, Roberto / Sánchez-Doblado, Francisco / Leal, Antonio / Lagares, Juan Ignacio / Arráns, Rafael / Hartmann, Günther H

    Medical physics

    2004  Volume 31, Issue 9, Page(s) 2416–2422

    Abstract: Intensity modulated radiation therapy (IMRT) has evolved toward the use of many small radiation fields, or "beamlets," to increase the resolution of the intensity map. The size of smaller beamlets can be typically about 1-5 cm2. Therefore small ... ...

    Abstract Intensity modulated radiation therapy (IMRT) has evolved toward the use of many small radiation fields, or "beamlets," to increase the resolution of the intensity map. The size of smaller beamlets can be typically about 1-5 cm2. Therefore small ionization chambers (IC) with sensitive volumes < or = 0.1 cm3 are generally used for dose verification of IMRT treatment. The dosimetry of these narrow photon beams pertains to the so-called nonreference conditions for beam calibration. The use of ion chambers for such narrow beams remains questionable due to the lack of electron equilibrium in most of the field. The present contribution aims to estimate, by the Monte Carlo (MC) method, the total correction needed to convert the IBA-Wellhöfer NAC007 micro IC measured charge in such radiation field to the absolute dose to water. Detailed geometrical simulation of the microionization chamber was performed. The ion chamber was always positioned at a 10 cm depth in water, parallel to the beam axis. The delivered doses to air and water cavity were calculated using the CAVRZ EGSnrc user code. The 6 MV phase-spaces for Primus Clinac (Siemens) used as an input to the CAVRZnrc code were derived by BEAM/EGS4 modeling of the treatment head of the machine along with the multileaf collimator [Sánchez-Doblado et al., Phys. Med. Biol. 48, 2081-2099 (2003)] and contrasted with experimental measurements. Dose calculations were carried out for two irradiation geometries, namely, the reference 10x10 cm2 field and an irregular (approximately 2x2 cm2) IMRT beamlet. The dose measured by the ion chamber is estimated by MC simulation as a dose averaged over the air cavity inside the ion-chamber (Dair). The absorbed dose to water is derived as the dose deposited inside the same volume, in the same geometrical position, filled and surrounded by water (Dwater) in the absence of the ionization chamber. Therefore, the Dwater/Dair dose ratio is a MC direct estimation of the total correction factor needed to convert the absorbed dose in air to absorbed dose to water. The dose ratio was calculated for several chamber positions, starting from the penumbra region around the beamlet along the two diagonals crossing the radiation field. For this quantity from 0 up to a 3% difference is observed between the dose ratio values obtained within the small irregular IMRT beamlet in comparison with the dose ratio derived for the reference 10x10 cm2 field. Greater differences from the reference value up to 9% were obtained in the penumbra region of the small IMRT beamlet.
    MeSH term(s) Algorithms ; Computer Simulation ; Equipment Failure Analysis/methods ; Models, Statistical ; Monte Carlo Method ; Radiometry/instrumentation ; Radiometry/methods ; Radiometry/standards ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted/instrumentation ; Radiotherapy Planning, Computer-Assisted/methods ; Radiotherapy Planning, Computer-Assisted/standards ; Radiotherapy, Conformal/instrumentation ; Radiotherapy, Conformal/methods ; Radiotherapy, Conformal/standards ; Reproducibility of Results ; Sensitivity and Specificity
    Language English
    Publishing date 2004-09
    Publishing country United States
    Document type Comparative Study ; Evaluation Studies ; Journal Article ; Research Support, Non-U.S. Gov't ; Validation Studies
    ZDB-ID 188780-4
    ISSN 0094-2405
    ISSN 0094-2405
    DOI 10.1118/1.1767691
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article: Cross-sections of the reaction 232Th(p,3n)230Pa for production of 230U for targeted alpha therapy.

    Morgenstern, Alfred / Apostolidis, Christos / Bruchertseifer, Frank / Capote, Roberto / Gouder, Thomas / Simonelli, Federica / Sin, Mihaela / Abbas, Kamel

    Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine

    2008  Volume 66, Issue 10, Page(s) 1275–1280

    Abstract: 230)U/(226)Th is a promising novel alpha-emitter system for application in targeted alpha therapy of cancer. The therapeutic nuclides can be produced by proton irradiation of natural (232)Th according to the reaction (232)Th(p,3n)(230)Pa, followed by ... ...

    Abstract (230)U/(226)Th is a promising novel alpha-emitter system for application in targeted alpha therapy of cancer. The therapeutic nuclides can be produced by proton irradiation of natural (232)Th according to the reaction (232)Th(p,3n)(230)Pa, followed by subsequent beta decay of (230)Pa to (230)U. In this study, the experimental excitation function for the (232)Th(p,3n)(230)Pa reaction up to 34 MeV proton energy has been measured using the stacked-foil technique. The proton energies in the various foils were calculated with the SRIM 2003 code and gamma-ray spectrometry was used to measure the activities of the various radioisotopes produced. The measured cross-sections are in good agreement with selected literature values and with model calculations using the EMPIRE II code. The reaction (232)Th(p,3n)(230)Pa allows the production of carrier-free (230)U in clinically relevant levels.
    MeSH term(s) Alpha Particles/therapeutic use ; Computer Simulation ; Models, Chemical ; Protactinium/chemistry ; Radiotherapy/methods ; Thorium/chemistry ; Uranium/chemistry ; Uranium/therapeutic use
    Chemical Substances Protactinium (0S6855V29M) ; Uranium (4OC371KSTK) ; Thorium (60YU5MIG9W)
    Language English
    Publishing date 2008-10
    Publishing country England
    Document type Journal Article
    ZDB-ID 1142596-9
    ISSN 1872-9800 ; 0969-8043 ; 0883-2889
    ISSN (online) 1872-9800
    ISSN 0969-8043 ; 0883-2889
    DOI 10.1016/j.apradiso.2008.02.066
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: Uncertainty estimation in intensity-modulated radiotherapy absolute dosimetry verification.

    Sánchez-Doblado, Francisco / Hartmann, Günther H / Pena, Javier / Capote, Roberto / Paiusco, Marta / Rhein, Bernhard / Leal, Antonio / Lagares, Juan Ignacio

    International journal of radiation oncology, biology, physics

    2007  Volume 68, Issue 1, Page(s) 301–310

    Abstract: Purpose: Intensity-modulated radiotherapy (IMRT) represents an important method for improving RT. The IMRT relative dosimetry checks are well established; however, open questions remain in reference dosimetry with ionization chambers (ICs). The main ... ...

    Abstract Purpose: Intensity-modulated radiotherapy (IMRT) represents an important method for improving RT. The IMRT relative dosimetry checks are well established; however, open questions remain in reference dosimetry with ionization chambers (ICs). The main problem is the departure of the measurement conditions from the reference ones; thus, additional uncertainty is introduced into the dose determination. The goal of this study was to assess this effect systematically.
    Methods and materials: Monte Carlo calculations and dosimetric measurements with five different detectors were performed for a number of representative IMRT cases, covering both step-and-shoot and dynamic delivery.
    Results: Using ICs with volumes of about 0.125 cm(3) or less, good agreement was observed among the detectors in most of the situations studied. These results also agreed well with the Monte Carlo-calculated nonreference correction factors (c factors). Additionally, we found a general correlation between the IC position relative to a segment and the derived correction factor c, which can be used to estimate the expected overall uncertainty of the treatment.
    Conclusion: The increase of the reference dose relative standard uncertainty measured with ICs introduced by nonreference conditions when verifying an entire IMRT plan is about 1-1.5%, provided that appropriate small-volume chambers are used. The overall standard uncertainty of the measured IMRT dose amounts to about 2.3%, including the 0.5% of reproducibility and 1.5% of uncertainty associated with the beam calibration factor. Solid state detectors and large-volume chambers are not well suited to IMRT verification dosimetry because of the greater uncertainties. An action level of 5% is appropriate for IMRT verification. Greater discrepancies should lead to a review of the dosimetric procedure, including visual inspection of treatment segments and energy fluence.
    MeSH term(s) Calibration ; Monte Carlo Method ; Quality Control ; Radiometry/instrumentation ; Radiometry/standards ; Radiotherapy Dosage/standards ; Radiotherapy, Intensity-Modulated/standards ; Reference Values ; Uncertainty
    Language English
    Publishing date 2007-05-01
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 197614-x
    ISSN 1879-355X ; 0360-3016
    ISSN (online) 1879-355X
    ISSN 0360-3016
    DOI 10.1016/j.ijrobp.2006.11.056
    Database MEDical Literature Analysis and Retrieval System OnLINE

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