[en] The Alto project means the installation of an electron linear accelerator inside the experimental area of the tandem accelerator of the nuclear physics institute of Orsay (IPNO, France). This linear accelerator comes from CERN where it was operating as a pre-injector for LEP. This equipment will allow IPNO'teams to perform fast kinetics studies in a domain different from that of ELYSE accelerator. The time resolution will not be as high as that of ELYSE (picosecond) but will be sufficient (microsecond) to produce free radicals in aqueous and gaseous media. The main expectations of this installation can be classified according 3 axis: 1) basic research (mainly the study of nuclear matter through photo-fission, 2) research and development of accelerators (by providing a test bench for new high frequency systems and superconducting components), and 3) applied research for industry concerning: biochemistry under irradiation, radiation sensibility, DNA breaking, food and drug sterilization and behaviour of electronic components under irradiation. This rapport details the research program that could be achieved with this equipment, describes its contributions in terms of economic development, cooperation with industry, student training, and specifies the needed investment and the operating and maintenance costs. (A.C.)

[en] The installation of electron Linac at Orsay in the framework of ALTO project is dedicated to fundamental research on exotic nuclei and to other interdisciplinary research subjects, particularly in industrial applications. In fundamental research, the main goal of ALTO is to supply interesting neutron-rich nuclear beams produced from the photo-fission process

[en] Published in summary form only

[en] To fulfill the need of a plasma ion source for SPIRAL-2 and EURISOL, capable of producing radioactive ion beams under strong radiation, the first prototype of the IRENA (Ionization by Radial Electrons Neat Adaptation) ion source has been designed. For designing an optimized prototype based on the first one, the influence of the geometrical parameters on the electron trajectories is investigated by means of two-dimensional/three-dimensional (3D) simulations. Due to the strong space charge effect in this kind of ion source, 3D simulations help particularly to better estimate effects on ion confinement and extraction. Simulation constructions will be presented and results discussed

[en] An intense source of spin-polarized electrons with the highest possible figure of merit was decided to be constructed. Its aim is to apply it at an existing European electron synchrotron like NIKHEF during 1993. The electron source uses optically pumped flowing helium afterglow, similarly to the design of the Rice University Source. The design and operation of the polarized electron source is described, its status, preliminary results and future perspectives are discussed. (R.P.) 5 refs., 6 figs

[en] The latest results as well as the operating principle and experimental arrangement of the Orsay polarized electron source are presented. The close-quote 94 performance, which has revealed 82%endash 70% electron polarization for currents up to 30 μA, 60% for 100 μA and a maximum quality factor IP²≅3.9 10^-5 Amp, is discussed. Finally we comment up-on our future development. copyright 1995 American Institute of Physics

[en] The recent development of high energy electron accelerators has generated a renewed interest in high current, high polarization electron sources. We have investigated several modifications to a method based on a pumped helium afterglow from which we expect improvements over the performances. These ones include the development of a high power, tunable LNA laser and the application of a new optical pumping scheme to the metastable helium atoms

[en] The measured optical properties of the Orsay polarized electron source, based on the He(2₃S1) + CO₂ Penning ionization reaction are presented. The upper limit on the beam energy spread is 0.25 eV, corresponding to our experimental resolution. The highest normalized emittance obtained at low current (1 μA) is 0.7 π mm mrad. The behaviour of these beam characteristics as a function of different relevant parameters is discussed. (author)

[en] The Orsay polarized electron source based on the chemi-ionization of aligned He(2³S₁) atoms and CO₂ molecules is briefly described. The latest results concerning electron polarization and beam emittance are presented. The present development status is also discussed. (K.A.)

[en] A diode-pumped Nd:Lanthanum Magnesium Hexaluminate laser was constructed which provides up to 15mW of single-mode, tunable CW emission at 1083 nm. By appropriately polarizing the narrow-band laser emission (< 10 MHz), the laser can be used to determine the populations of the magnetic substates of the He(2³S₁) atoms. The laser is tuned to one of the absorption peaks of the helium metastable atom by tilting a thin (1 mm) absorption is measured. The relative absorption is used to determine the ensemble polarization; the absolute absorption yields the metastable density