[en] A first irradiation with particles of energy low enough not to go through the membrane is carried out, a second irradiation on the other face creating in the same way blind tracks that meet in the middle of the membrane. After chemical etching pores are created giving a good selectivity for filtration membrane

[en] The membrane is irradiated twice, especially with heavy ions, once with an energy to low to pass through, then with enough energy. Molecular defects created by irradiation are preferentially attached by chemicals. Two pore networks are obtained: blind large diameter pores and fine pores through the membrane which can be used in filtration

[en] The release of small gaseous molecules is a general phenomenon of irradiated polymers. Polyethylene (PE), polypropylene (PP) and polybutene (PB) were irradiated with ions of different electronic stopping power. We show that the gas emission can provide important information on the damage process if a reliable chemical identification of the molecules released and accurate yield values are obtained. The outgassing products were analysed by two techniques: (1) by a novel set-up using a Fourier Transform Infrared (FTIR) analysis of the gas mixture released from the polymer film and (2) by residual gas analysis (RGA) with a quadrupole mass spectrometer. Comparing the analytical potentialities of both methods we come to the conclusion that the FTIR method gives a more straightforward and accurate determination of the chemical nature and of the yield of most of the released molecules. However, RGA provides complementary information on the gas release kinetics and also on the release of heavy hydrocarbon molecules and symmetric molecules like molecular hydrogen

[en] The effects of swift heavy ions in non-biological matter have been extensively studied during the last few years. Some results on non-biological solids are summarised here which might help to analyse comparatively the effects of high linear energy transfer (LET) particles in biological and non-biological matter. Special emphasis is put on the effects recently observed in organic solids. The experimental study of high-LET effects involves the use of accelerators and irradiation facilities. However, the requirements differ markedly from one study to the next, and ion accelerators of very different types have been used. A synthetic review of the existing sources and facilities is presented. (orig.). With 3 figs., 1 tab

[en] We present results of simultaneous in situ luminescence and optical absorption studies in scintillator CsI and CsI-Tl crystals, exposed to very dense electronic excitations induced by ⁸⁶Kr ions (8.63 MeV/amu). Irradiation at 15 K leads to the formation of the prominent F absorption band. In addition, several other features of the broad absorption between exciton and F bands were ascribed to an anion vacancy, α centre (240 nm), self-trapped hole, V_k centre (410 nm) and interstitials, H centres (560 nm). We have found that low doping of thallium (∼10¹⁷ cm^-3) causes the F centre formation to proceed more rapidly than in pure crystal. On the other hand, we were not able to create any amount of F centres in heavily doped CsI-Tl. We have shown that point defects created by heavy ions manifested themselves in luminescence ageing

[en] There is now a set of experimental data showing that in some systems there is a marked effect of the electronic stopping power on the radiation induced defect production in electrical conductors. Organic metals are one of these systems. It has been demonstrated that, from the point of view of radiation effects, organic metals behave like normal insulating molecular crystals rather than metals. A contribution from electronic energy losses to radiation damage has also been observed in several other electrical conductors but only in a regime of a very high density of excitation and ionization, ie, when the electronic stopping power (dE/dx) is very large. In this presentation, we shall deal with this high dE/dx regime, which is the slowing down regime of swift heavy ion irradiations. The main results which have been obtained with organic metals, high T_c copper oxides, amorphous metallic alloys, crystalline metallic alloys and pure metals, are reviewed. (author)

[en] The damage processes triggered by swift heavy ions, SHI, can be very different to those induced by classical low ionising particles. This is due to the very high electronic stopping power, (dE/dx)_e, of SHI. This paper concerns the effects of SHI on polyethylene, PE. In PE, low (dE/dx)_e irradiations induce crosslinking and in-chain double bond formation. At high (dE/dx)_e, the creation yield of vinyl groups becomes significant. Above a (dE/dx)_e threshold, alkyne and allene groups appear. We present results on low temperature irradiations that bring new enlightenment on the damage process by preventing the migration of radiation-induced radicals and molecules. Two SHI specific modifications are studied: vinyl groups and alkyne end groups. We have irradiated PE films with oxygen and sulphur beams at 13.6 and 11.2 MeV/amu, respectively. The modifications were followed by in situ infrared spectroscopy (FTIR). We have performed irradiations at 8 and 290 K. The samples irradiated at 8 K have been annealed up to 290 K for investigating the effect of radical migration. Lowering the irradiation temperature to 8 K increases the creation yield of vinyl groups and alkyne end groups. The enhancement factor between 290 and 8 K is around three. Consequently the formation of defects specific to SHI irradiations is sensitive to radical migration and hence requires some time. During annealing, the alkyne concentration remains stable indicating that the creation of this group cannot be induced by radical recombination. The annealing spectra of vinyl groups are more complex

[en] Short communication

[en] We have studied X-ray luminescence of KNbO₃ single crystal. The 575 nm luminescence band has been studied in the temperature range of 15-45 K. The quenching parameters were found to be Q=12±3 meV and ν=4x10¹¹ s^-1. No luminescence has been observed under heavy ion excitation (⁸⁶Kr ions, 8.63 MeV/amu) even at 15 K

[en] The present compilation gives an overview of experimental results obtained with the GANIL facility during the period 1996-1997. It includes nuclear physics activities as well as interdisciplinary research. The scientific domain presented here extends well beyond the traditional nuclear physics and includes atomic physics, condensed matter physics, nuclear astrophysics, radiation chemistry, radiobiology as well as applied physics. In the nuclear physics field, many new results have been obtained concerning nuclear structure as well as the dynamics of nuclear collisions and nuclear disassembly of complex systems. Results presented deal in particular with the problem of energy equilibration, timescales and the origin of multifragmentation. Nuclear structure studies using both stable and radioactive beams deal with halo systems, study of shell closures far from stability, the existence of nuclear molecules as well as measurements of fundamental data s half lives, nuclear masses, nuclear radii, quadrupole and magnetic moments. In addition to traditional fields of atomic and solid state physics, new themes such as radiation chemistry and radiobiology are progressively being tackled. (K.A.)