| 1. |
- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 2. |
- Battistoni, G, et al.
(författare)
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FLUKA Monte Carlo calculations for hadrontherapy application
- 2013
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Ingår i: CERN-Proceedings-2012-002. ; , s. 461-467
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Konferensbidrag (refereegranskat)abstract
- Monte Carlo (MC) codes are increasingly spreading in the hadrontherapy community due to their detailed description of radiation transport and interaction with matter. The suitability of a MC code for application to hadrontherapy demands accurate and reliable physical models for the description of the transport and the interaction of all components of the expected radiation field (ions, hadrons, electrons, positrons and photons). This contribution will address the specific case of the general-purpose particle and interaction code FLUKA. In this work, an application of FLUKA will be presented, i.e. establishing CT (computed tomography)-based calculations of physical and RBE (relative biological effectiveness)-weighted dose distributions in scanned carbon ion beam therapy.
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| 3. |
- Ballarini, F., et al.
(författare)
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The physics of the FLUKA code : Recent developments
- 2007
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Ingår i: Advances in Space Research. - Elsevier : Elsevier BV. - 0273-1177 .- 1879-1948. ; 40:9, s. 1339-1349
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Tidskriftsartikel (refereegranskat)abstract
- FLUKA is a Monte-Carlo code able to simulate interaction and transport of hadrons, heavy ions and electromagnetic particles from few keV (or thermal neutron) to cosmic ray energies in whichever material. The highest priority in the design and development of the code has always been the implementation and improvement of sound and modern physical models. A summary of the FLUKA physical models is given, while recent developments are described in detail: among the others, extensions of the intermediate energy hadronic interaction generator, refinements in photon cross sections and interaction models, analytical on-line evolution of radio-activation and remnant dose. In particular, new developments in the nucleus-nucleus interaction models are discussed. Comparisons with experimental data and examples of applications of relevance for space radiation are also provided.
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| 4. |
- Battistoni, G., et al.
(författare)
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The FLUKA code and its use in hadron therapy
- 2008
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Ingår i: Nuovo Cimento della Societa Italiana di Fisica C. - Italian Physical Society. - 1124-1896. ; 31:1, s. 69-75
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Tidskriftsartikel (refereegranskat)abstract
- FLUKA is a multipurpose Monte Carto code describing transport and interaction with matter of a, large variety of particles over a wide energy range ill complex geometries. FLUKA is successfully applied ill several fields, including, but not only particle physics, cosmic-ray physics, dosimetry, radioprotection, hadron therapy. space radiation, accelerator design and neutronics. Here we briefly review recent model developments and provide examples of applications to hadron therapy, including calculation of physical and biological dose for comparison with analytical treatment planning engines as well as beta(+)-activation for therapy monitoring by means of positron emission tomography.
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| 5. |
- Pinsky, L., et al.
(författare)
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Measurement of Fragmentation Products including Angular Distributions for 3, 5, and 10 GeV/A C and Si on several nuclear targets at the AGS
- 2010
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Ingår i: 2009 12th International Conference on Nuclear Reaction Mechanisms, NRM 2009; Varenna; Italy; 15 June 2009 through 19 June 2009. - 2078-8835. - 9789290833413 ; 2, s. 431-437
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Konferensbidrag (refereegranskat)abstract
- Motivated by differences in the predicted fragmentation of heavy ions at energies around 5 GeV/A as employed in the event generators used by the FLUKA Monte Carlo Code [1], a set of measurements were carried out at the AGS facility at the Brookhaven National Laboratory to determine as much information as possible about the cross sections to allow harmonization of those event generators for these incident lab energies. The FLUKA Code employs the RQMD event generator of Sorge [2] for heavy ion interactions starting at 100 MeV/A and extending into the region around 5 GeV/A. Above those energies the DPMJET code of Ranft and Roesler [3] is typically employed to simulate such interactions. The detailed predictions of these event generators had some disagreement in the vicinity of this crossover energy and in order to tune these codes to be in closer harmony at the transition, and of course to be simulating nature as closely as possible, data were taken at 3, 5 and 10 GeV/A with beams of Fe, Si and C on a variety of targets including C, A1. Fe and Cu. The Fe data have not been fully analyzed, but results from the C and Si beams are available and the forward fragment spectrum along with a measurement of the charged particle angular distribution in a set of Si strip detectors out to about 45 degrees in the lab are available. These include sufficient statistics to provide the charged particle distributions as a function of the major projectile fragment. The detectors used in this measurement were based on what were reasonably available to us, and as such were limited in capability, and required separate data acquisition systems. Nevertheless, spectra were obtained that should be sufficient to enable the harmonization of the event generator codes at the crossover energy. This paper discusses only the experimental results and not the impact of those results on the FLUKA code.
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| 6. |
- Sihver, Lembit, 1962, et al.
(författare)
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A comparison of total reaction cross section models used in FLUKA, GEANT4 and PHITS
- 2012
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Ingår i: Aerospace Conference, 2012 IEEE. ; , s. 1-10, s. 1 - 10
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Konferensbidrag (refereegranskat)abstract
- Understanding the interactions and propagations of high energy protons and heavy ions are essential when trying to estimate the biological effects of Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE) on personnel on interplanetary missions, and when preparing the construction of a lunar base. To be able to calculate the secondary particles, including neutrons, and to estimate shielding properties of different materials and radiation risks inside complex geometries, particle and heavy ion transport codes are needed. The interactions of the GCR and SPE with matter include many complex properties and many factors influence the calculated results. In all particle and heavy ion transport codes, the probability function that a projectile particle will collide with a nucleus within a certain distance x in the matter depends on the total reaction cross sections, which also scale the calculated partial fragmentation cross sections. It is therefore crucial that accurate total reaction cross section models are used in the transport calculations. FLUKA, GEANT4 and PHITS are three major multi-purpose three-dimensional Monte Carlo particle and heavy ion transport codes widely used for fundamental research, radioprotection, radiotherapy, and space dosimetry. In this paper, a systematic comparison of the total reaction cross section models used as default in these three codes is performed for a variety of systems of importance for space dosimetry, and the need for future improvements and benchmarking against experimental results is discussed. The need for benchmarking and improvements of the partial nuclear reaction and evaporation models, as well as how impact parameter functions, switching time between the dynamical/pre-equilibrium and the de-excitation/evaporation stages, low energy data libraries, etc., influence the final results, is also briefly be discussed.
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| 7. |
- Böhlen, Till Tobias, et al.
(författare)
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A Monte Carlo-based treatment-planning tool for ion beam therapy
- 2013
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Ingår i: Journal of radiation research. - : Oxford University Press (OUP). - 0449-3060 .- 1349-9157. ; 54, s. 77-81
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Tidskriftsartikel (refereegranskat)abstract
- Ion beam therapy, as an emerging radiation therapy modality, requires continuous efforts to develop and improve tools for patient treatment planning (TP) and research applications. Dose and fluence computation algorithms using the Monte Carlo (MC) technique have served for decades as reference tools for accurate dose computations for radiotherapy. In this work, a novel MC-based treatment-planning (MCTP) tool for ion beam therapy using the pencil beam scanning technique is presented. It allows single-field and simultaneous multiple-fields optimization for realistic patient treatment conditions and for dosimetric quality assurance for irradiation conditions at state-of-the-art ion beam therapy facilities. It employs iterative procedures that allow for the optimization of absorbed dose and relative biological effectiveness (RBE)-weighted dose using radiobiological input tables generated by external RBE models. Using a re-implementation of the local effect model (LEM), the MCTP tool is able to perform TP studies using ions with atomic numbers Z < 8. Example treatment plans created with the MCTP tool are presented for carbon ions in comparison with a certified analytical treatment-planning system. Furthermore, the usage of the tool to compute and optimize mixed-ion treatment plans, i.e. plans including pencil beams of ions with different atomic numbers, is demonstrated. The tool is aimed for future use in research applications and to support treatment planning at ion beam facilities.
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| 8. |
- Böhlen, Till Tobias, et al.
(författare)
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Benchmarking nuclear models of FLUKA and GEANT4 for carbon ion therapy
- 2010
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Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 0031-9155 .- 1361-6560. ; 55:19, s. 5833-5847
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Tidskriftsartikel (refereegranskat)abstract
- As carbon ions, at therapeutic energies, penetrate tissue, they undergo inelastic nuclear reactions and give rise to significant yields of secondary fragment fluences. Therefore, an accurate prediction of these fluences resulting from the primary carbon interactions is necessary in the patient's body in order to precisely simulate the spatial dose distribution and the resulting biological effect. In this paper, the performance of nuclear fragmentation models of the Monte Carlo transport codes, FLUKA and GEANT4, in tissue-like media and for an energy regime relevant for therapeutic carbon ions is investigated. The ability of these Monte Carlo codes to reproduce experimental data of charge-changing cross sections and integral and differential yields of secondary charged fragments is evaluated. For the fragment yields, the main focus is on the consideration of experimental approximations and uncertainties such as the energy measurement by time-of-flight. For GEANT4, the hadronic models G4BinaryLightIonReaction and G4QMD are benchmarked together with some recently enhanced de-excitation models. For non-differential quantities, discrepancies of some tens of percent are found for both codes. For differential quantities, even larger deviations are found. Implications of these findings for the therapeutic use of carbon ions are discussed.
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| 9. |
- Böhlen, Till Tobias, et al.
(författare)
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FLUKA simulations of the response of tissue-equivalent proportional counters to ion beams for applications in hadron therapy and space
- 2011
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Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 0031-9155 .- 1361-6560. ; 56:20, s. 6545-6561
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Tidskriftsartikel (refereegranskat)abstract
- For both cancer therapy with protons and ions (hadron therapy) and space radiation environments, the spatial energy deposition patterns of the radiation fields are of importance for quantifying the resulting radiation damage in biological structures. Tissue-equivalent proportional counters (TEPC) are the principal instruments for measuring imparted energy on a microscopic scale and for characterizing energy deposition patterns of radiation. Moreover, the distribution of imparted energy can serve as a complementary quantity to particle fluences of the primary beam and secondary fragments for characterizing a radiation field on a physical basis for radiobiological models. In this work, the Monte Carlo particle transport code FLUKA is used for simulating energy depositions in TEPC by ion beams. The capability of FLUKA in predicting imparted energy and derived quantities, such as lineal energy, for microscopic volumes is evaluated by comparing it with a large set of TEPC measurements for different ion beams with atomic numbers ranging from 1 to 26 and energies from 80 up to 1000 MeV/n. The influence of different physics configurations in the simulation is also discussed. It is demonstrated that FLUKA can simulate energy deposition patterns of ions in TEPC cavities accurately and that it provides an adequate description of the main features of the spectra.
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| 10. |
- Böhlen, Till Tobias, et al.
(författare)
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Investigating the robustness of ion beam therapy treatment plans to uncertainties in biological treatment parameters
- 2012
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Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 0031-9155 .- 1361-6560. ; 57:23, s. 7983-8004
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Tidskriftsartikel (refereegranskat)abstract
- Uncertainties in determining clinically-used relative biological effectiveness (RBE) values for ion beam therapy carry the risk of absolute and relative misestimations of RBE-weighted doses for clinical scenarios. The present study assesses the consequences of hypothetical misestimations of input parameters to the RBE modelling for carbon ion treatment plans by a variational approach. The impact of the variations on resulting cell survival and RBE values is evaluated as a function of the remaining ion range. In addition, the sensitivity to misestimations in RBE modelling is compared for single fields and two opposed fields using differing optimization criteria. It is demonstrated for single treatment fields that moderate variations (up to ±50%) of representative nominal input parameters for four tumours result mainly in a misestimation of the RBE-weighted dose in the planning target volume (PTV) by a constant factor and only smaller RBE-weighted dose gradients. Ensuring a more uniform radiation quality in the PTV eases the clinical importance of uncertainties in the radiobiological treatment parameters as for such a condition uncertainties tend to result only in a systematic misestimation of RBE-weighted dose in the PTV by a constant factor. Two opposed carbon ion fields with a constant RBE in the PTV are found to result in rather robust conditions. Treatments using two ion species may be used to achieve a constant RBE in the PTV irrespective of the size and depth of the spread-out Bragg peak.
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