A horizontal beam facility for radiobiological experiments with low-energy protons has been set up at the 4MV Van de Graaff accelerator of the Institut de Physique Nucléaire de Lyon. A homogeneous irradiation field with a suitable proton flux is obtained by means of two collimators and two Au-scattering foils. A monitoring chamber contains a movable Faraday cup, a movable quartz beam viewer for controlling the intensity and the position of the initial incident beam and four scintillating fibers for beam monitoring during the irradiation of the cell samples. The beam line is ended by a thin aluminized Mylar window (12μm thick) for the beam extraction in air. The set-up was simulated by the GATE v6.1 Monte-Carlo platform. The measurement of the proton energy distribution, the evaluation of the fluence-homogeneity over the sample and the calibration of the monitoring system were performed using a silicon PIPS detector, placed in air in the same position as the biological samples to be irradiated. The irradiation proton fluence was found to be homogeneous to within ±2% over a circular field of 20mm diameter. As preliminary biological experiment, two Human Head and Neck Squamous Carcinoma Cell lines (with different radiosensitivities) were irradiated with 2.9MeV protons. The measured survival curves are compared to those obtained after X-ray irradiation, giving a Relative Biological Efficiency between 1.3 and 1.4.

2012 is the penultimate year of financial support by the CPER 2007-2013 for ETOILE's research program, sustained by the PRRH at the University Claude Bernard. As with each edition we make the annual review of the research in this group, so active for over 12 years now. Over the difficulties in the decision-making process for the implementation of the ETOILE Center, towards which all our efforts are focussed, some themes (work packages) were strengthened, others have progressed, or have been dropped. This is the case of the eighth theme (technological developments), centered around the technology for rotative beam distribution heads (gantries) and, after being synchronized with the developments of ULICE's WP6, remained so by ceasing its activities, coinciding also with the retirement of its historic leader at IPNL, Marcel Bajard. Topic number 5 (In silico simulations) has suffered the departure of its leader, Benjamin Ribba, although the work has still been provided by Branka Bernard, a former postdoctoral fellow in Lyon Sud, and now back home in Croatia, still in contract with UCBL for the ULICE project. Aside from these two issues (and the fact that the theme Medico-economical simulations is now directly linked to the first one (Medical Project), the rest of the teams are growing, as evidenced by the publication statistics at the beginning of this report. This is obviously due to the financial support of our always faithful regional institutions, but also to the synergy that the previous years, the European projects, the arrival of the PRIMES LabEx, and the national France Hadron infrastructure have managed to impulse. The Rhone-Alpes hadron team, which naturally includes the researchers of LPC at Clermont, should also see its influence result in a strong presence in France Hadron's regional node, which is being organized. The future of this regional research is not yet fully guaranteed, especially in the still uncertain context of ETOILE, but the tracks are beginning to emerge to allow past and present efforts translate into a long future that we all want to see established. Each of the researchers in PRRH is aware that 2013 will be (and already is) the year of great challenge : for ETOILE, for the PRRH, for hadron therapy in France, for French hadrontherapy in Europe (after the opening and beginning of treatments in the German [HIT Heidelberg, Marburg], Italian [CNAO, Pavia] and Austrian [MedAustron, Wien Neuerstadt]) centers. Let us meet again in early 2014 for a comprehensive review of the past and a perspective for the future ...

at the 4MV Van de Graaff accelerator of the Institut de Physique Nucleaire de Lyon. At this energy, the Relative Biological Effectiveness (RBE) of protons may amount to 2-7 [1], platform constitutes thus a tool to study the specific effects of high-LET radiations to cells. For such macroscopic-irradiation facilities, the dose distribution over the cell samples has to be uniform with accuracy better than ±5% and a controlled dose rate (2 Gy/min for clinical interest). The range of protons in the sample has to be controlled to ensure a track-segment irradiation protocol. A homogeneous irradiation field with a suitable proton flux is obtained by means of two collimators (various sizes) and two Au-scattering foils arrangements set 62 cm apart from each other. The last arrangement is set 120 cm upstream from the irradiation area. A monitoring chamber contains a movable Faraday cup, a movable quartz beam viewer for controlling the position and the intensity of the initial incident beam, four scintillating fibers for beam monitoring during the irradiation of the cell samples, and is ended by a thin aluminized mylar window (12 μm thick) for the beam extraction in air. The set-up was simulated by the GATE v6.1 Monte-Carlo platform. The facility performance were tested with 3.5 MeV protons using a silicon PIPS detector, placed in air in the same position as the biological samples to be irradiated, for proton energy measurement, fluence-homogeneity evaluation and flux calibration. With this double scattering system, a fluence heterogeneity of ±3% over a circular field of 20 mm diameter was obtained. A preliminary biological experiment was performed to test protocols with two Human Head and Neck Squamous cell lines carcinoma with quite different radiosensitivities. Cells were irradiated at 2Gy with a dose rate of 2Gy/min. DNA Double Strand Break induction and repair, were measured by scoring the γH2AX foci. Results will be presented and discussed.

Sputtering and ion emission rates have been measured from CsI and gold targets under the impact of Aun+ (n=1–9) clusters at energies between 30 and 350keV/atom. The two materials have similar behaviors in regard to the variations of the sputtering and anion emission yields with energy and cluster size. The sputtering and anion emission yields increase nonlinearly with the projectile size. The maximum anion yields are found at lower energies than the maximum sputtering yields which themselves occur substantially below the maximum energy losses. The variations with energy of the atomic ion yields differ from those of the cluster ion yields. The experimental results are in agreement with an ion emission from linear collision cascades and spike collisions, the relative contribution of these two processes depending on the size of the cluster projectile and of the emitted ion. In addition they show that the ion emission yield enhancements under cluster impact result from a more effective sputtering mechanism and not from an enhanced ionization of the ejected species.

Au nanoislet targets (∅ 2–60nm) were bombarded by 200keV polyatomic ions (40keV/atom), which deposit their energy mainly in the nuclear stopping mode: ∑(dE/dx)n=30keV/nm and ∑(dE/dx)e=2keV/nm. The matter desorbed in the form of nanoclusters was registered by TEM. The total transfer of matter was determined by neutron-activation analysis. The total yield of the ejected gold reached high values of up to 2.6×104 atoms per Au5 ion. The major part (2×104 atoms per ion Au5) of the emission is in the form of nanoclusters. The results are compared with the data of similar experiments with 1MeV Au5 (200keV/atom) and other projectiles. The analysis of the experimental data and the comparison to molecular-dynamics simulation results of the desorption process show that the desorption of Au nanoislets is induced by their melting, build-up of pressure and thermal expansion.

A thin germanium crystal has been irradiated at GANIL by Pb beams of 29MeV/A (charge state Qin=56 and 72) and of 5.6MeV/A (Qin=28). The induced ion emission from the sample entrance surface was studied, impact per impact, as a function of Qin, velocity vin and energy loss ΔE in the crystal. The Pb ions transmitted through the crystal were analyzed in charge (Qout) and energy using the SPEG spectrometer. The emitted ionized species were detected and analyzed in mass by a time-Of-flight multianode detector (LAG). Channeling was used to select peculiar ΔE values in Ge and hence peculiar Pb ion trajectories close to the emitting entrance surface. The experiment was performed in standard vacuum. No Ge emission was found. The dominating emitted species are H+ and hydrocarbon ions originating from the contamination layer on top of the crystal. The mean value 〈M〉 of the number of detected species per incoming Pb ion (multiplicity) varies as (Qin/vin)p, with p values in agreement with previous results. We have clearly observed an influence of the energy deposition ΔE in Ge on the emission from the top contamination layer. When selecting increasing values of ΔE, we observed a rather slow increase of 〈M〉. On the contrary, the probabilities of high multiplicity values, which are essentially connected to fragmentation after emission, strongly increase with ΔE.

Nanodispersed gold targets (2–100nm grains) were bombarded for the first time in the nuclear stopping region by 1MeV Au5 cluster ions (∑(dE/dx)n=45keV/nm and (∑(dE/dx)e=4.5keV/nm in gold). The total yield of the ejected gold reached high values – up to ∼1.2×105 at./ion (Au5) for the grains with sizes comparable with the range of the 200keV gold ions (∼18nm). The size spectra of gold nanoparticles on the targets were compared with those of ejected gold nanoparticles collected on carbon foils supported by TEM grids. No gold nanoparticles larger than 35nm appeared in the size spectra of the ejected nanoparticles.

A Au-Si liquid metal ion source which produces Au(n) clusters over a large range of sizes was used to study the dependence of both the molecular ion desorption yield and the damage cross-section on the size (n = 1 to 400) and on the kinetic energy (E = 10 to 500 keV) of the clusters used to bombard bioorganic surfaces. Three pure peptides with molecular masses between 750 and 1200 Da were used without matrix. [M+H](+) and [M+cation](+) ion emission yields were enhanced by as much as three orders of magnitude when bombarding with Au(400) (4+) instead of monatomic Au(+), yet very little damage was induced in the samples. A 100-fold increase in the molecular ion yield was observed when the incident energy of Au(9) (+) was varied from 10 to 180 keV. Values of emission yields and damage cross-sections are presented as a function of cluster size and energy. The possibility to adjust both cluster size and energy, depending on the application, makes the analysis of biomolecules by secondary ion mass spectrometry an extremely powerful and flexible technique, particularly when combined with orthogonal time-of-flight mass spectrometry that then allows fast measurements using small primary ion beam currents.

The assessment of the plasma desorption time-of-flight mass spectrometry (PD-TOFMS) technique as a tool for direct characterization of pesticides adsorbed on agricultural soil is made for the first time in this study. Pellets of soils impregnated by solutions of three pesticides, namely norflurazon, malathion and oxyfluorfen, as well as deposits of these solutions onto aluminum surfaces, were investigated to this end. The yield values of the most characteristic peaks of the negative ion mass spectra were used to determine both the lowest concentrations detected on soils and limits of detection from thin films. The lowest values on soils are for malathion (1000 ppm range), and the largest for norflurazon (20 000 ppm), which is close to the limit of detection (LOD) found for the pesticide on the aluminum substrate (similar to 0.2 mu g center dot cm(-2)). Different behaviors were observed as a function of time of storage in the ambient atmosphere or under vacuum; norflurazon adsorbed on soil exhibited high stability for a long period of time, and a rapid degradation of malathion with the elapsed time was clearly observed. The behavior of oxyfluorfen was also investigated but segregation processes seem to occur after several days. Although by far less sensitive than conventional methods based on extraction processes and used for real-world analytical applications, this technique is well suited to the study of the transformations occurring at the sample surface. A discussion is presented of the future prospects of such experiments in degradation studies. Copyright (C) 2005 John Wiley & Sons, Ltd.

Under impact of 150-keV/atom Au-n(+) projectiles (1less than or equal tonless than or equal to9) on gold targets the emission yield of anionic clusters increases much faster with n than expected from simple proportionality. Moreover the anion size distribution is much wider for bombardment by clusters. The cluster yield enhancements reflect the size dependence of the cluster stability according to the electronic shell structure. Accordingly, the most intense emission is observed for Au-7(-): under Au-9(+) impact the Au-7(-) yield per incident atom is enhanced by a factor of similar to6.

The total sputtering yields of gold and silver targets bombarded by Au n (n = 1-13) clusters have been measured over a broad range of incident energy per atom (from 20 keV/atom to 5 MeV/atom). Large nonlinear effects in the sputtering yields were observed. For silver targets, yield values as high as ∼20 000 atoms per impact of Au 1 3 at 1.2 MeV (92 keV/atom) were measured while only 45 atoms are emitted from the same target in the impact of single gold atoms at the same energy per atom. The sputtering yield variation with incident projectile energy per atom shows that maxima occur at ∼250 keV/atom for a gold target and ∼150 keV/atom for a silver target for projectiles with three or more atoms. In both cases the maxima of nuclear stopping power are at much larger energies per atom (700 keV for Au on Au and 550 keV for Au on Ag). Large surface deformations with craters and rims are observed by atomic force microscopy at the surface of cluster irradiated targets. Their number per unit area corresponds to the irradiation fluence and they are of approximately the same size, demonstrating that fluctuations between events are small.

Gold cluster beams delivered by the 2.5 MV Van de Graaff accelerator of the Institut de Physique Nucleaire de Lyon, equipped with a liquid metal ion source (LMIS), were used for secondary electron emission measurements. We investigated backward emission from thin carbon and gold targets bombarded by Au: projectiles (1 less than or equal to n less than or equal to 9) of energies between 150 and 500 keV/atom in a standard vacuum of 10(-7) mbar. For Au(+) ions incident on carbon and gold targets it is observed that the electron yield follows the velocity dependence of the energy deposited at the surface of the target in ionization processes induced both by the incident projectile and by the recoiling target atoms. For Au(n)(+) clusters of a given velocity the electron yield per incident gold atom is observed to decrease when the cluster size increases. Given the large contribution of the recoil atoms to the electron emission. we studied the dependence of the cluster effect on the target thickness, for thicknesses of the order of the size of the atomic displacement cascades. The comparison of the electron yields of thin carbon targets of various thicknesses at the impact of Au* and Au(n)(p) projectiles of the same velocity has effectively evidenced a thickness effect for cluster induced electron emission. (C) 2000 Elsevier Science B.V. All rights reserved.

Silicon wafers of (1 0 0) orientation were irradiated with Au, cluster beams (1 less than or equal to n less than or equal to 7) produced by the 3.5 MV Van de Graaff accelerator of the Institut de Physique Nucleaire de Lyon equipped with a liquid metal source. The incident energy was of 200 keV per gold atom, which corresponds to a slowing-down mainly governed by elastic processes (nuclear energy loss of Au+ ions: 3 keV nm(-1)). All the irradiations were performed at room temperature with fluences up to 5 x 10(14) Au (at. cm(-2)). The typical beam currents varied from 1.5 nA for Au' down to 20 pA for Au-7(+). The radiation-induced disorder was measured by means of Rutherford backscattering spectrometry in channeling geometry (RBS-C), using a He-4(+) beam accelerated at 2 MV. From the fluence evolution of the lattice disorder at the target surface, we evidence that polyatomic projectiles produce more defects per incident atom than single Au' ions. As an example we measured damage cross-sections per incident Au atom of 12.5 and 2.7 nm(2) for Au; and Au' projectiles, respectively. This cluster effect was ascribed to the high density of nuclear energy deposited within the cascade. Transmission electron microscopy (TEM) was performed on samples irradiated at low fluences (10(9) at. cm(=2)) in order to visualize each projectile impact. (C) 2000 Elsevier Science B.V. All rights reserved.

A liquid metal ion source (LMIS) was installed on the high-voltage terminal of the 2.5 MV single-stage Van de Graaff accelerator of the Institut de Physique Nucléaire de Lyon and was used to deliver intense MeV energy beams of cluster ions. After acceleration, the ions produced from an eutectic Au–Si alloy were mass-selected by means of a magnetic analysis. The beam was mainly composed of the monoatomic ions Au+ and Si+ and of the clusters Au n +, Au n Si+, and Au n Si2+ (n=2-13). The intensities decreased for increasing n values, but remained remarkably high. For pure gold ions, the maximum intensity measured at the target site varied from 250 nA, for Au+, down to 20 pA, for Au9+. The research program on the study of the specific effects of the impact of energetic clusters on solid surfaces concerns the fundamental interaction processes and the solid modifications induced by high-density energy deposits. Our first experiments with Au n + clusters led to the following results: Nonlinear dependence on the cluster size of kinetic secondary electron emission from thin carbon foil enhances the damage rate of irradiated silicon crystals as compared to monoatomic Au+ ion effects.

The emission statistics of secondary electrons emitted from solid targets under ion impact has been recently the object of much interest from a theoretical as well as experimental point of view since it provides very useful information about the electron excitation process in the solid. In the case of very thin targets, it is possible to measure simultaneously the number of electrons emitted from both sides of the target and the exit charge state of the projectile. The resulting two variable (number of electrons emitted in the backward and in the forward directions) statistical distribution shows in some cases a clear correlation between the numbers of electrons emitted from both sides of the target. This correlation between backward and forward emission has been studied from Monte Carlo simulations and from experiments for H0 and H+ projectiles incident on thin carbon foils in the MeV energy range. It is shown that the charge exchange processes of the incident projectiles in the target play an important role in the interpretation of the backward–forward correlation of the secondary electron emission.

The secondary electron emission has been measured for 2 MeV H+ and for H-0 projectiles passing through very thin carbon foils without charge changing. We have studied the statistics of the emission from both entrance and emergence surfaces. Simultaneously, Monte Carlo calculations have been performed for similar experimental conditions (500 keV < E < 2 MeV). Both experimental and theoretical distributions can be fitted adequately by Polya distributions. The measured and calculated differences of the yields and of the distribution widths between the H+ and "transmitted" H-0 cases are interpreted in terms of screening effects on the large impact parameter collisions with target electrons. (C) 1998 Elsevier Science B.V.

We have performed projectile-by-projectile measurements of backward and forward secondary-electron emission of thin carbon foils under impact of MeV H-0 projectiles. The emitted electrons were detected in coincidence with the protons or the neutrals emerging from the target. We have used a very thin target for which we know that, at energies above 2 MeV, the emergent neutrals are essentially transmitted, i.e., they have kept their electron throughout the target. In these conditions the emission yields measured in coincidence with nt neutrals are found lower than for protons of the same velocity, but the reduction factor is not the same for backward and for forward emission. We show that this can be explained by the screening of the proton charge by the electron during the H-0-target interaction. We have observed other effects related to forward electron emission: if the H-0 projectile emerging from the foils results from an electron-capture event taking place close to the exit surface, the forward emission is enhanced (at energies above 500 keV) by the contribution of Auger electrons resulting from the rearrangement of the carbon atoms ionized in the capture events. For H-0 projectiles ionized in the target we have used the statistics of the number of forward-emitted electrons to deduce the probability for an incident electron to be transmitted through a very thin target and to produce cascade electrons. [S1050-2947(97)05812-5].