| 1. |
- Gudowska, Irena, et al.
(författare)
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Verification of the multiple scattering and energy loss straggling algorithms for therapeutic light ion beams implemented in a semi-analytical pencil beam model and the MC code SHIELD-HIT; benchmark with experiments
- 2007
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Ingår i: The 11th Workshop of Ion Beams in Biology and Medicine, 25-29 September 2007, Heidelberg, Germany, ISSN 1013-4506, p. 55 (2007).
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Konferensbidrag (populärvet., debatt m.m.)abstract
- The increased interest in radiation therapy with light ions calls for fast calculation of the dose distribution of narrow charged particle beams. In order to accurately calculate the physical dose and biological effect distribution of light ions in matter, a physical beam transport model has to be set up.A fast semi-analytical model used for calculation of energy deposition of narrow ion beams in water has been developed (Hollmark et al 2004, Hollmark et al 2007). The model applied the Fermi-Eyges theory for simultaneous calculation of multiple scattering and energy loss straggling of light ion beams traversing water. The developed semi-analytical algorithm incorporates the energy deposition kernels calculated by the Monte Carlo transport code SHIELD-HIT, in which ion scattering and energy straggling processes were suppressed. The analytical dose distributions are calculated by weighting the SHIELD-HIT calculated dose with analytical Gaussian multiple scattering and straggling distributions. Both primary and secondary particles are considered in this study. To evaluate the influence of the lightest secondary particles (nuclear charges Z=1 and Z=2) on the total lateral dose distribution, primary and secondary dose distributions are calculated separately.The multiple scattering and radial energy deposition of fragments produced along the ion path are calculated analytically as well as simulated by SHIELD-HIT. The results are verified against experimental data of the transverse energy deposition for clinical proton beams of energies 62 MeV from CATANA facility, LNS – INFN, Italy and 180 MeV from the TSL Laboratory, Uppsala, Sweden. The multiple scattering processes of primary carbon beams and their secondaries are discussed for experimental beams of 290 MeV/u (HIMAC, Chiba, Japan) and 400 MeV/u (GSI, Darmstadt, Germany).Hollmark et al. “Influence of multiple scattering and energy loss straggling on the absorbed dose distributions of therapeutic light ion beams: I. Analytical pencil beam model” Phys. Med. Biol. 49 pp. 3247-3265 (2004)Hollmark et al. “Influence of multiple scattering and energy loss straggling on the absorbed dose distributions of therapeutic light ion beams: II. Semi-analytical narrow beam model” manuscript (2007)
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| 2. |
- Torrisi, Lorenzo, et al.
(författare)
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High intensity laser-generating plasmas in forward direction in thin films and Thomson parabola spectrometer monitorage
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Asterix laser at PALS Laboratory of Prague, operating at 1315 nm fundamental wavelength, 300 ps pulse duration, 1016 W/cm2 intensity and single pulse mode, was employed to irradiate thin hydrogenated targets placed in high vacuum. Non-equilibrium plasmas were obtained in forward direction, i.e. along the normal to the target surface on the rear of the irradiated thin films. Plasmas were monitored with different ion detectors, placed around the direction normal to the target. The main detector was a Thomson parabola spectrometer aligned along the normal in forward direction. This spectrometer permits to provide many plasma parameters concerning the involved ions (energy, charge state, mass,...) obtained in a single laser shot. The spectrometer images, obtained by using a MCP coupled to a fast CCD camera, can be processed by a comparison with the simulation data obtained by a proper software. High ion energies and charge states have been obtained as a function of the laser parameters, target thickness and composition and irradiation conditions.
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| 3. |
- Torrisi, Lorenzo, et al.
(författare)
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Proton driven acceleration by intense laser pulses irradiating thin hydrogenated targets
- 2013
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Ingår i: Applied Surface Science. - : Elsevier. - 0169-4332 .- 1873-5584. ; 272, s. 2-5
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Tidskriftsartikel (refereegranskat)abstract
- The Asterix iodine laser of the PALS laboratory in Prague, operating at 1315 nm fundamental frequency, 300 ps pulse duration, 600 J maximum pulse energy and 1016 W/cm2 intensity, is employed to irradiatethin hydrogenated targets placed in high vacuum. Different metallic and polymeric targets allow togenerate multi-energetic and multi-specie ion beams showing peculiar properties. The plasma obtainedby the laser irradiation is monitored, in terms of properties of the emitted charge particles, by using time-of-flight techniques and Thomson parabola spectrometer (TPS). A particular attention is given tothe proton beam production in terms of the maximum energy, emission yield and angular distributionas a function of the laser energy, focal position (FP), target thickness and composition.
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