[en] This publication contains two articles. The first one aims at giving an assessment of energy production potential of biomass in France at a regional level. It gives estimates of volumes of breeding effluents in the different French regions and according to a low and a high hypothesis, presents various technologies used to produce energy from these effluents (examples in Denmark and in Great-Britain), gives estimates of quantities of wheat or barley straws which could be used for energy production in the different French regions and describes straw-based Danish cogeneration plants, gives estimates for other energetic crops (some trees and herbaceous crops) and reports the Belgium experience. The second text reports a middle-term or long-term prospective and economical feasibility study on the production of geothermal energy from fractured rocks. Some researches have already demonstrated the feasibility of a heat exchanger on very deep and cracked granitic rocks which could supply hot water that could be used for energy production. The study examines the different possibilities of evolution of this concept (deepness, increase in the number of wells, transformation into heat, electricity or cogeneration) and describes their technical and economical characteristics within an industrial development perspective on the long term

[en] The purpose of this investigation was the development of a scattering system for a proton therapy beam line dedicated to ophtalmological applications. A protontherapy beam line has been developed for the treatment of uveal melanoma at the Orsay synchrocyclotron. The original 200 MeV proton beam is degraded to 76 MeV and the final beam characteristics (range, modulation, flatness, collimation) are obtained with beam modifiers in the treatment room. A passive scattering system is used to obtain a uniform dose distribution in the beam cross-section throughout 30 min in diameter, with minimal losses in energy and dose rate. We have used an experimental approach for the scattering study. An elliptical ring shaped from 0.1-mm thick lead is the solution we have adopted for the scattering system. For a modulated beam, a flatness of 1% is obtained on transverse profiles. The energy loss introduced by this scatterer is only 0.5 MeV, with no appreciable change in the range over the treatment field. For an unmodulated beam, 21% of intensity is lost when the scatterer is used. The distal and the lateral dose fall-off (90-10%) for a modulated beam are 2.6 mm. These last values are independent of the range and the modulation currently used for the ophtalmic applications. A specific passive scattering system can be adapted to a particular beam emittance. A systematic experimental approach can easily be undertaken to obtain the scatterer adapted for small irradiation fields in proton therapy. 13 refs., 12 figs

[en] Different codes of practice are in use or under preparation by several groups and national or international societies, concerning the dosimetry of proton beams. In spite of a large number of experiences and the increasing interest on this field, there are still large incertitudes on some of the basic conversion and correction factors to get dose values from different measuring methods. In practice, dose uniformity between centers is searched and encouraged by intercomparisons using standard procedures. We present the characteristics and the results on proton dosimetry intercomparisons using calorimeters, Faraday cups and ion chambers, as well as on the use of other detectors like diodes, radiographic films and TLD. New detectors like diamond, scintillators, radiochromic films, alanine, gels, ... can give new solutions to particular problems, provided their response is not affected at the end of the proton range (higher LET region), and their resolution, range, linearity, cost, ... are well adapted to practical situations. Some examples of special challenges are non interfering measurements during treatments for quality control, in vivo measurements, small beams for stereotactic irradiations, scanned beams and correlations between dosimetry, microdosimetry and radiobiology

[en] Full text: At the French proton therapy facility (CPO), treatments of choroid melanoma and skull base tumors are respectively performed with 73 and 200 MeV protons. Secondary radiations, mainly high-energy neutrons, produced along the beam line and in the beam delivering system, lead to secondary exposure during treatment. A study was performed first to estimate secondary exposure to the patient, second to map dose in the treatment room in order to evaluate the dose delivered to the different electronic devices and finally to establish correction factors for fixed neutron monitors installed in the radiation-controlled zone delimited around the room treatment. A dosimetric study according to the complexity of the radiation environment in term of type of particles and energy spectra (very high energy), requires the use of fitted detectors. In this work, in order to estimate dose and dose equivalent in the periphery of the beam and also in the vicinity of the room treatments, measurements were performed using tissue-equivalent proportional counters (TEPC), a Studsvik rem counter and solid state track detectors (PN3). TEPC instrument is the most suitable detector for high-energy mixed radiation field. Prior measurements in CPO, the TEPC response was studied in different neutron beam facilities, the response varies to ± 15 % for neutrons energy from 0,5 to 60 MeV. Analysis of TEPC measurements performed in the room treatment showed that high LET component (>10 keV.μm^-1) represent 90 to 99 % of total dose equivalent and quality factors range between 7 and 15. Studsvik and fixed neutron monitors measurements underestimate high LET TEPC values by a factor 2 to 6 following the location. Dose equivalent rate for the different configurations and locations in the room treatment varied between few hundred μSv.h^-1 to few hundred mSv.h^-1. The highest dose rate was measured at the position of the camera used for positioning the patient. The variation of LET spectra and nature of particle following location is discussed. The equivalent dose in patient position was found to be mainly due to secondary neutrons whereas the equivalent dose, downstream the delivering system, at the position of the camera, was assumed to be mainly due to scattered fast protons coming from the delivering system. (author)

[en] Short communication

[en] Short communication

No abstract available

[en] Short communication

[en] Short communication

[en] Short communication