| Records |
| Author |
Ortega, P.G.; Torres-Espallardo, I.; Cerutti, F.; Ferrari, A.; Gillam, J.E.; Lacasta, C.; Llosa, G.; Oliver, J.F.; Sala, P.R.; Solevi, P.; Rafecas, M. |
| Title |
Noise evaluation of Compton camera imaging for proton therapy |
Type |
Journal Article |
| Year |
2015 |
Publication |
Physics in Medicine and Biology |
Abbreviated Journal |
Phys. Med. Biol. |
Volume  |
60 |
Issue |
5 |
Pages |
1845-1863 |
| Keywords |
proton therapy; Compton camera; Monte Carlo methods; FLUKA; prompt gamma; range verification; MLEM |
| Abstract |
Compton Cameras emerged as an alternative for real-time dose monitoring techniques for Particle Therapy (PT), based on the detection of prompt-gammas. As a consequence of the Compton scattering process, the gamma origin point can be restricted onto the surface of a cone (Compton cone). Through image reconstruction techniques, the distribution of the gamma emitters can be estimated, using cone-surfaces backprojections of the Compton cones through the image space, along with more sophisticated statistical methods to improve the image quality. To calculate the Compton cone required for image reconstruction, either two interactions, the last being photoelectric absorption, or three scatter interactions are needed. Because of the high energy of the photons in PT the first option might not be adequate, as the photon is not absorbed in general. However, the second option is less efficient. That is the reason to resort to spectral reconstructions, where the incoming. energy is considered as a variable in the reconstruction inverse problem. Jointly with prompt gamma, secondary neutrons and scattered photons, not strongly correlated with the dose map, can also reach the imaging detector and produce false events. These events deteriorate the image quality. Also, high intensity beams can produce particle accumulation in the camera, which lead to an increase of random coincidences, meaning events which gather measurements from different incoming particles. The noise scenario is expected to be different if double or triple events are used, and consequently, the reconstructed images can be affected differently by spurious data. The aim of the present work is to study the effect of false events in the reconstructed image, evaluating their impact in the determination of the beam particle ranges. A simulation study that includes misidentified events (neutrons and random coincidences) in the final image of a Compton Telescope for PT monitoring is presented. The complete chain of detection, from the beam particle entering a phantom to the event classification, is simulated using FLUKA. The range determination is later estimated from the reconstructed image obtained from a two and three-event algorithm based on Maximum Likelihood Expectation Maximization. The neutron background and random coincidences due to a therapeutic-like time structure are analyzed for mono-energetic proton beams. The time structure of the beam is included in the simulations, which will affect the rate of particles entering the detector. |
| Address |
[Ortega, P. G.; Cerutti, F.; Ferrari, A.] CERN European Org Nucl Res, CH-1217 Meyrin, Switzerland, Email: pgarciao@cern.ch |
| Corporate Author |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0031-9155 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000349530700009 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2115 |
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| Author |
Hornillos, M.B.G.; Gorlychev, V.; Caballero, R.; Cortes, G.; Poch, A.; Pretel, C.; Calvino, F.; Tain, J.L.; Algora, A.; Agramunt, J.; Cano-Ott, D.; Martinez, T.; Mendoza, E.; Rissanen, J.; Aysto, J.; Jokinen, A.; Eronen, T.; Moore, I.; Penttila, H. |
| Title |
Monte Carlo Simulations for the Study of a Moderated Neutron Detector |
Type |
Journal Article |
| Year |
2011 |
Publication |
Journal of the Korean Physical Society |
Abbreviated Journal |
J. Korean Phys. Soc. |
| Volume |
59 |
Issue |
2 |
Pages |
1573-1576 |
| Keywords |
Monte Carlo simulations; GEANT4; MCNPX; Beta delayed neutron emission; Neutron detector |
| Abstract |
This work presents the Monte Carlo simulations performed with the MCNPX and GEANT4 codes for the design of a BEta deLayEd Neutron detector, BELEN-20. This detector will be used for the study of beta delayed neutron emission and consists of a block of polyethylene with dimensions 90 x 90 x 80 cm(3) and 20 cylindrical (3)He gas counters. The results of these simulations have been validated experimentally with a (252)Cf source in the laboratory at UPC, Barcelona. Also the first experiment with this detector has been carried out in November 2009 in JYFL, Finland. In this experiment the neutron emission probability after beta decay of the fission products (88)Br, (94,95)Rb, and (138)I has been measured; this data is still under analysis. Simulations with MCNPX and GEANT4 have been performed in order to obtain the efficiency of the BELEN-20 detector for each of the above nuclei using the neutron energy distribution corresponding to each nucleus. |
| Address |
[Hornillos, MBG; Gorlychev, V; Caballero, R; Cortes, G; Poch, A; Pretel, C; Calvino, F] Univ Politecn Cataluna, Seccio Engn Nucl, E-08028 Barcelona, Spain, Email: belen.gomez@upc.edu |
| Corporate Author |
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Thesis |
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| Publisher |
Korean Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0374-4884 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000294080700028 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ elepoucu @ |
Serial |
733 |
| Permanent link to this record |
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| Author |
n_TOF Collaboration (Mendoza, E. et al); Giubrone, G.; Tain, J.L. |
| Title |
Improved Neutron Capture Cross Section Measurements with the n_TOF Total Absorption Calorimeter |
Type |
Journal Article |
| Year |
2011 |
Publication |
Journal of the Korean Physical Society |
Abbreviated Journal |
J. Korean Phys. Soc. |
| Volume |
59 |
Issue |
2 |
Pages |
1813-1816 |
| Keywords |
ND2010; Nuclear data; n_TOF; Background; Monte Carlo; Neutron; Time of flight; Cross section; Calorimeter; Shielding; Simulation; Total absorption; Gamma ray; Neutron capture |
| Abstract |
The n_TOF collaboration operates a Total Absorption Calorimeter (TAC) [1] for measuring neutron capture cross-sections of low-mass and/or radioactive samples. The results obtained with the TAC have led to a substantial improvement of the capture cross sections of (237)Np and (240)Pu [2]. The experience acquired during the first measurements has allowed us to optimize the performance of the TAC and to improve the capture signal to background ratio, thus opening the way to more complex and demanding measurements on rare radioactive materials. The new design has been reached by a series of detailed Monte Carlo simulations of complete experiments and dedicated test measurements. The new capture setup will be presented and the main achievements highlighted. |
| Address |
[Mendoza, E; Becares, V; Casado, A; Cano-Ott, D; Fernandez-Ordonez, M; Gonzalez-Romero, E; Guerrero, C; Martinez, T; Vidriales, JJ] Ctr Invest Energet Medioambientales & Tecnol, Madrid 28040, Spain, Email: emilio.mendoza@ciemat.es |
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Thesis |
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| Publisher |
Korean Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0374-4884 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000294080700086 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ elepoucu @ |
Serial |
738 |
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| Author |
Romero-Barrientos, J.; Marquez Damian, J.I.; Molina, F.; Zambra, M.; Aguilera, P.; Lopez-Usquiano, F.; Parra, B.; Ruiz, A. |
| Title |
Calculation of kinetic parameters beta eff and L with modified open source Monte Carlo code OpenMC(TD) |
Type |
Journal Article |
| Year |
2022 |
Publication |
Nuclear Engineering and Technology |
Abbreviated Journal |
Nucl. Eng. Technol. |
| Volume |
54 |
Issue |
3 |
Pages |
811-816 |
| Keywords |
OpenMC; Monte Carlo; Kinetic parameters; Open source; Neutron generation time; Effective delayed neutron fraction |
| Abstract |
This work presents the methodology used to expand the capabilities of the Monte Carlo code OpenMC for the calculation of reactor kinetic parameters: effective delayed neutron fraction beff and neutron generation time L. The modified code, OpenMC(Time-Dependent) or OpenMC(TD), was then used to calculate the effective delayed neutron fraction by using the prompt method, while the neutron generation time was estimated using the pulsed method, fitting L to the decay of the neutron population. OpenMC(TD) is intended to serve as an alternative for the estimation of kinetic parameters when licensed codes are not available. The results obtained are compared to experimental data and MCNP calculated values for 18 benchmark configurations. |
| Address |
[Romero-Barrientos, J.; Molina, F.; Zambra, M.; Aguilera, P.; Lopez-Usquiano, F.; Ruiz, A.] Comis Chilena Energia Nucl, Santiago 12501, Chile, Email: romeroj@uchile.cl |
| Corporate Author |
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Thesis |
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| Publisher |
Korean Nuclear Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1738-5733 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000766649800004 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5172 |
| Permanent link to this record |
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| Author |
Fletcher, E.M.; Ballester, F.; Beaulieu, L.; Morrison, H.; Poher, A.; Rivard, M.J.; Sloboda, R.S.; Vijande, J.; Thomson, R.M. |
| Title |
Generation and comparison of 3D dosimetric reference datasets for COMS eye plaque brachytherapy using model-based dose calculations |
Type |
Journal Article |
| Year |
2024 |
Publication |
Medical Physics |
Abbreviated Journal |
Med. Phys. |
| Volume |
51 |
Issue |
|
Pages |
694-706 |
| Keywords |
Monte Carlo; ocular brachytherapy; treatment planning |
| Abstract |
PurposeA joint Working Group of the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy and Oncology (ESTRO), and the Australasian Brachytherapy Group (ABG) was created to aid in the transition from the AAPM TG-43 dose calculation formalism, the current standard, to model-based dose calculations. This work establishes the first test cases for low-energy photon-emitting brachytherapy using model-based dose calculation algorithms (MBDCAs).Acquisition and Validation MethodsFive test cases are developed: (1) a single model 6711 125I brachytherapy seed in water, 13 seeds (2) individually and (3) in combination in water, (4) the full Collaborative Ocular Melanoma Study (COMS) 16-mm eye plaque in water, and (5) the full plaque in a realistic eye phantom. Calculations are done with four Monte Carlo (MC) codes and a research version of a commercial treatment planning system (TPS). For all test cases, local agreement of MC codes was within & SIM;2.5% and global agreement was & SIM;2% (4% for test case 5). MC agreement was within expected uncertainties. Local agreement of TPS with MC was within 5% for test case 1 and & SIM;20% for test cases 4 and 5, and global agreement was within 0.4% for test case 1 and 10% for test cases 4 and 5.Data Format and Usage NotesDose distributions for each set of MC and TPS calculations are available online () along with input files and all other information necessary to repeat the calculations.Potential ApplicationsThese data can be used to support commissioning of MBDCAs for low-energy brachytherapy as recommended by TGs 186 and 221 and AAPM Report 372. This work additionally lays out a sample framework for the development of test cases that can be extended to other applications beyond eye plaque brachytherapy. |
| Address |
[Fletcher, Elizabeth M.; Thomson, Rowan M.] Carleton Univ, Phys Dept, Carleton Lab Radiotherapy Phys, Ottawa, ON, Canada, Email: rthomson@physics.carleton.ca |
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Thesis |
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| Publisher |
Wiley |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0094-2405 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:001058112300001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5632 |
| Permanent link to this record |
