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Resume Le marquage cellulaire radioisotopique (MCR) des elements figures du sang est une technique couramment impliquee dans la realisation d’examen diagnostique relevant de la medecine nucleaire ; elle n’a jamais ete definie juridiquement. Cette indetermination juridique est un facteur d’insecurite tant pour les patients que pour les professionnels de sante concernes. L’objectif de ce travail etait d’identifier la nature juridique de la cellule radiomarquee en confrontant ses elements constitutifs aux differentes categories juridiques existantes relevant du droit du vivant et du droit des produits de sante. L’etude conclut qu’en l’etat du droit la cellule sanguine radiomarquee appartient sans conteste a la categorie du medicament par fonction ; plus precisement elle est assimilable a un medicament radiopharmaceutique issu d’un processus de preparation. Afin de renforcer la visibilite et donc la prise en compte par les acteurs des contraintes qui en decoulent, il est propose de creer un regime juridique specifique de la cellule radiomarquee en inscrivant a l’article L. 5121-1 du code de la sante publique une nouvelle categorie appelee : preparation radiopharmaceutique d’elements figures du sang a visee diagnostique. La portee de cette disposition placera mecaniquement la preparation des cellules radiomarquees dans le champ de competence exclusif des radiopharmaciens exercant dans une pharmacie a usage interieur ; autre consequence importante : en rentrant dans le champ d’application des bonnes pratiques de pharmacie hospitaliere et des bonnes pratiques de preparation, le processus de radiomarquage des cellules sanguines beneficiera d’un cadre reglementaire protecteur de la securite des patients.

Radiolabelling of blood cells is a technique commonly used as a diagnostic tool in nuclear medicine; it has never been legally defined. This lack of legal status is a factor of uncertainty for both patients and health care professionals. The aim of this work was to identify what could be the legal nature of the radiolabelled blood cells by comparing their constitutive elements to the various existing legal categories applicable, according to the law applicable to living organisms as well as the regulations for other health products. The study concludes that, as it stands, the radiolabelled blood cells undoubtedly belong to the category of a drug by function for diagnostic purpose. More precisely, it is compared to a radiopharmaceutical medicinal product resulting from a well characterised manufacturing process. In order to increase visibility and thus the actors' awareness of the constraints arising from this specific status, it is proposed to create a specific legal regime for the radiolabelled blood cells by including in Article L. 5121-1 of the French Public Health Code a new category of health product which could be called: radiopharmaceutical preparation of cellular blood component for diagnostic purposes. The consequence of this proposal will mechanically place the radiolabelled blood cell preparation under the exclusive competences of radiopharmacists practising in an hospital pharmacy. Another important consequence will be that the radiolabelling process of blood cells will have to fulfil the rules of the French good hospital pharmacy practices and good preparation practices, for the benefit of patient protection and safety.

The SEVIRI instrument on board Meteosat Second Generation (MSG) offers new capabilities to monitor aerosol transport over the Atlantic and the Mediterranean at high temporal and spatial resolutions, in particular, Saharan dust from North Africa, biomass-burning aerosols from subtropical Africa and pollution from Europe. An inversion technique was developed to estimate both aerosol optical thickness and Angström coefficients from SEVIRI measurements at 0.63 and 0.81 µm. This method relies on an optimized set of aerosol models to ensure a fast processing of full-resolution MSG images and to allow the processing of long time series. SEVIRI images for slots 45, 49 and 53 (11:15, 12:15, 13:15 UT) were processed for June 2003. The retrieved optical thicknesses and Angström coefficients are in good agreement with AERONET in-situ measurements in the Atlantic and in the Mediterranean. Monthly mean maps of both parameters are compared to that obtained with the polar orbiting sensor POLDER for June 2003. There is a good consistency between the two monthly means in terms of optical thickness, but the Angström coefficients show significant differences in the Atlantic zone which is affected by dust transport. These differences may be explained by the lack of specific non-spherical dust models within the inversion. The preliminary results presented in this paper demonstrate, nevertheless, the potential of MSG/SEVIRI for the monitoring of aerosol optical properties at high frequencies over the Atlantic and the Mediterranean.

The exclusive 2H( 3He, t)2p reaction has been studied at 2 GeV for energy transfers up to 500 MeV and triton angles up to 3.4°. The protons were measured in the large acceptance magnetic detector DIOGENE, in coincidence with the forward tritons detected in a dedicated magnetic arm. The energy transfer spectra extend well above the pion threshold. However, in the region of Δ excitation, the yield is less than 10% of the inclusive 2H( 3He, t) cross-section, which indicates the small contribution of the ΔN ↦ NN process. The angular distributions of the two protons in their center of mass have been analysed as a function of energy transfer and triton angle and a Legendre polynomial decomposition has been achieved. These data have been compared to a model based on a coupled-channel approach for describing the NN and NΔ systems.

Angular distributions for the differential cross section and three deuteron analyzing powers {ital iT}{sub 11}, {ital T}{sub 20}, and {ital T}{sub 22} of the reaction {ital d}{searrow}{ital p}{r_arrow}{sup 3}He{pi}{sup 0} have been measured over the whole angular domain at 20 energies close to threshold (0.03{lt}{ital T}{sub {pi}}{sup c.m.}{lt}10.2 MeV). The differential cross section and tensor analyzing power {ital T}{sub 20} both show strong variation in energy and angle due to interference between {ital S}- and {ital P}-wave pion production, whereas {ital iT}{sub 11} and {ital T}{sub 22} remain consistent with zero over the whole experimental range. All the data at different energies and angles fall on universal curves when plotted as functions of the single variable {ital p}{sub {pi}}cos{Theta}, evaluated in the c.m. The broad features of the results are in line with theoretical expectations. {copyright} {ital 1996 The American Physical Society.}

A search for the lepton-family-violating decay {eta}{r_arrow}{mu}{ital e} and the rare decay {eta}{r_arrow}{ital e}{sup +}{ital e}{sup {minus}} yields the following branching ratio ({ital B}) upper limits at a 90{percent} confidence level: {ital B}({eta}{r_arrow}{mu}{ital e}){lt}6{times}10{sup {minus}6} and {ital B}({eta}{r_arrow}{ital e}{sup +}{ital e}{sup {minus}}){lt}2{times}10{sup {minus}4}. This is the first direct search for {eta}{r_arrow}{mu}{ital e}. The measurements were carried out at the SPES2 tagged {eta} facility at Laboratoire National Saturne in the course of a measurement of {ital B}({eta}{r_arrow}{mu}{sup +}{mu}{sup {minus}}). {copyright} {ital 1996 The American Physical Society.}

The reaction {ital pd}{r_arrow}{sup 3}He{eta} has been studied with the SPES2 spectrometer, for proton energies between 0.2 MeV and 11 MeV above threshold. The total cross section rises from 0.25 to 0.40 {mu}b in this region. The observed energy dependence can be attributed to the strong final state interaction. The angular distribution is nearly isotropic, consistent with {ital S} wave production. A measurement of the {ital pd}{r_arrow}{sup 3}He{pi}{sup +}{pi}{sup {minus}} cross section in the threshold region is also presented. The setup, which is capable of producing 10{sup 5} tagged {eta}/s with only a few percent background, is used to investigate rare {eta} decays. {copyright} {ital 1996 The American Physical Society.}

A new measurement of the branching ratio for the decay \ensuremath{\eta}\ensuremath{\rightarrow}${\mathrm{\ensuremath{\mu}}}^{+}$${\mathrm{\ensuremath{\mu}}}^{\mathrm{\ensuremath{-}}}$, made at the SATURNE II proton synchrotron, resulted in \ensuremath{\Gamma}(\ensuremath{\eta}\ensuremath{\rightarrow}${\mathrm{\ensuremath{\mu}}}^{+}$${\mathrm{\ensuremath{\mu}}}^{\mathrm{\ensuremath{-}}}$)/\ensuremath{\Gamma}(\ensuremath{\eta}\ensuremath{\rightarrow}all)= [5.7\ifmmode\pm\else\textpm\fi{}0.7(stat.)\ifmmode\pm\else\textpm\fi{}0.5(syst.)]\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}6}$. The reaction pd${\ensuremath{\rightarrow}}^{3}$He\ensuremath{\eta} close to threshold yielded 800 ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$ tagged \ensuremath{\eta}'s in a narrow momentum band around 257 MeV/c. Muon pairs were detected in two range telescopes. The data obtained consist of 114 events \ensuremath{\eta}\ensuremath{\rightarrow}${\mathrm{\ensuremath{\mu}}}^{+}$${\mathrm{\ensuremath{\mu}}}^{\mathrm{\ensuremath{-}}}$ on a background of 14 events. The new value for the branching ratio is 1.3\ifmmode\pm\else\textpm\fi{}0.2 times the unitarity lower limit, consistent with most quark and vector meson dominance models which describe the decay as an electromagnetic transition with a two-photon intermediate state. The result resolves the discrepancy between the two previous measurements of this branching ratio.

Data are presented on the 12 C ( 3 He , t π + ) reaction at 2 GeV bombarding energy. In coincidence with forward scattered tritons, pions are momentum-analysed in a large acceptance detector. For events where the target is left in its g.s. or low-lying states, the angular correlation between the momentum transfer vector and the momentum of the pion is sharply peaked at small relative angles.

The excitation of theΔ resonance is observed in proton collisions on C, Nb and Pb targets at 0.8 and 1.6 GeV incident energies. The mass E0 and widthΓ of the resonance are determined from the invariant mass spectra of correlated (p, π±)-pairs in the final state of the collision: The mass E0 is smaller than that of the free resonance, however by comparing to intra-nuclear cascade calculations, this reduction is traced back to the effects of Fermi motion, NN scattering and pion reabsorption in nuclear matter.

Two-proton correlation functions at small relative momentum have been systematically studied with the large solid angle detector DIOGENE at Saturne for interactions induced by Ne and Ar beams on various targets, and incident energies per nucleon ranging from 200 to 1000 MeV. From these distributions, informations on the space-time structure of the source have been derived as a function of the centrality of the collision, the target-projectile combinations and the incident energy, using the model of Koonin. Special attention has been devoted to take into account all experimental biases in order to get the distorted theoretical correlation curves before comparison to the experimental data. Other interesting conclusions have been obtained when comparing the extracted source radii to the dimensions of the overlapping volume of target by projectile in a pure geometrical model of the collision (clean cut geometry). Some results concerning fragment-fragment small angle correlations are also presented.

The analysis of %-ray mult ip l ic i t ies measured I in coincidence with capture fission events in reactions of 26Mg through 54Cr, 58Fe, and 64Ni with 208pb in terms of Ko and~eff revealed1 that the resulting values of ~ /~e f f were rather independent of for a given system and, in a compound nucleus picture, were more in agreement with the 'shape of the non-rotating saddle than with the actually expected rotating saddle I f non-compound systenmhave to be considered these values of ~/J~ff__ shapes. suggested at least that the captured systems near the turning point from the inward radial motion to symmetric fragmentation had reached a remarkable compactness.

Recent results from the large solid angle detector “DIOGENE” at Saturne (Saclay), for Ne + A and Ar + A reactions at 400, 600 and 800 MeV per nucleon are presented. Several points are selected: 1) The particles azimuthal emission pattern (with respect to the reaction plane) exhibiting preferential out-of-plane emission at c.m. rapidities, 2) The presence of an appreciable amount of collective flow for asymmetric systems and even for (rather) small projectile masses, 3) The first measurements of “flow” and multiplicities for both positive and negative pions, 4) The first measurement of deltas in central relativistic heavy ion collisions.

Triple-differential cross sections of proton-like particles were obtained for Ne+NaF, Ne+Nb and Ne+Pb reactions at 800 MeV per nucleon from quasi-exclusive measurements. Their dependence upon the azimuthal angle with respect to the reaction plane is analyzed. In addition to the usual flow pattern, another component of the azimuthal dependence is observed. It can be parametrized using the second order parameters in Fourier series expansion. The dependence of this component upon transverse momentum, rapidity and impact parameter (multiplicity) is investigated.

Parallel plate avalanche counters have been designed and used for localization of relativistic heavy ions. They have been tested alpha particles from a 241Am source. They have been used with the heavy-ion beams from Saturne in conjunction with the 4π detector Diogene. They provide an accurate measurement of the vertex position with eficiency.

Emission of light fragments at small angles is studied in relativistic heavy ion collisions using the Diogene plastic wall for both symmetrical and non-symmetrical target-projectile systems with 400 MeV per nucleon and 800 MeV per nucleon incident neon nuclei. Efficiency of multiplicity measurements in the small angle range for the selection of central or peripheral collisions is confirmed for asymmetric systems. Differential production cross sections of Z = 1 fragments show evidence for the existence of two emitting sources. The apparent temperature of each source is obtained from comparison with a thermodynamical model.

We present here an overview of our quantitative studies of African dust transport to the Mediterranean, based on Meteosat and CZCS spaceborne images of the reflected sunlight, and coincident exogeneous meteorological and chemical atmospheric or marine data. Investigations include the retrieval of the desert dust aerosol optical thickness and mass column density over seawater, of the dust deposition flux and its fate in surface seawater. The comparison between measured and Meteosat-derived dust deposition fluxes indicates that cloud cover limits short-term Meteosat survey, but that long-term averaged dust fluxes to seawater can be approximated from Meteosat data. Results from our analysis of multi-year series of Meteosat ISCCP-B2 data indicate a marked seasonal cycle of dust transport in the Mediterranean, with a high dust load in spring and summer, and a strong year to year variability. A case study of the apparent velocity and altitude of dust transport shows a primary transport of dust particles above the atmospheric boundary layer. Finally, a combined survey of desert aerosol and phytoplankton in summertime seems to provide a first observation of the impact of strong dust inputs on the phytoplankton growth.

The successive operational Meteosat solar (VIS) sensors have shown significant variations of their spectral band which affected their relative sensitivities to the light scattering by aerosols, molecules and Earth surface. This paper provides a calibration of the various Meteosat VIS sensors used between June 1983, the beginning of data archiving for the International Satellite Cloud Climatology Project (ISCCP), and December 1994, taking into account the characteristics of their individual spectral band thanks to an atmospheric radiative transfer model. The method is based on a monitoring of the reflectance of desert and ocean targets free of clouds and aerosols, and relies on the absolute vicarious calibration of Meteosat-2 performed in late 1981. We find different sensitivities and temporal evolutions for Meteosat-2, -3, -4, and -5, and our results compare well with other more limited calibration studies

International audience; The reaction pp→pp$\pi$$^0$ has been investigated at the Satume accelerator using a transversely polarized beam of 800 MeV incident kinetic energy and the DIOGENE detector. We have measured the total cross section, the differential cross section as a function of the pion energy and the anisotropy parameter b. We find a strongly dominant contribution, greater than 90%, of the Delta resonance to this process. We have determined the analyzing power A$_y$ of the reaction and get negative values.

The results of intranuclear cascade calculations (ideal gas with two-body collisions and no mean field), complemented by a simple percolation procedure, are compared with experimental data on protons and light nuclear fragments ([ital d], [ital t], [sup 3]He, and [sup 4]He) measured in 400 and 800 MeV/nucleon Ne+Nb collisions using a large solid angle detector. The model reproduces quite well global experimental observables like nuclear fragment multiplicity distributions or production cross sections, and nuclear fragment to proton ratios. For rapidity distributions the best agreement occurs for peripheral reactions. Transverse momentum analysis confirms once again that the cascade, although being a microscopic approach, gives too small a collective flow, the best agreement being reached for [ital Z]=2 nuclear fragments. Nevertheless these comparisons are encouraging for further improvements of the model. Moreover, such an approach is easy to extend to any other models that could calculate the nucleon phase space distribution after the compression stage of the reaction, when light nuclear fragments emitted at large angles are constructed from percolation.

Correlations of oppositely charged pions produced in interactions of protons and light nuclei with different nuclear targets are investigated. The invariant-mass distributions are analyzed in order to search for new conjectured nuclear effects. Strong and electromagnetic final-state interactions between pions and the Coulomb interaction between pions and the target nucleus are taken into account. An admixture of pion pairs coming from resonance decays is estimated. An enhancement in the low invariant-mass region is observed only for heavy target systems. A shadowing effect due to pion absorption inside the nuclear medium is considered as a possible source of this pattern. Azimuthal π + π − correlations and pion yield dependence on the impact parameter, as well as transport calculations, seem to confirm this assumption.

The momentum distributions with respect to the reaction plane for charged pions emitted in Ne-nucleus and Ar-nucleus collisions have been measured with the 4 π detector Diogene at the Saturn synchrotron. The reaction plane is estimated from the baryon momenta, using a standard technique for flow analysis. The pions exhibit a non-zero flow. For asymmetric systems, there is a preferential emission in the direction of the lighter (projectile) nucleus. Such a behaviour contradicts the predictions of INC calculations and is underestimated by QMD calculations which include mean field effects. It can be interpreted with a simple geometrical model in terms of absorption by the spectator nuclear matter.

Deuteron spectra at laboratory angles from 30\ifmmode^\circ\else\textdegree\fi{} to 90\ifmmode^\circ\else\textdegree\fi{} were measured in \ensuremath{\alpha}+(Pb, Cu, and C) collisions at 800, 600, and 200 MeV/nucleon, and \ensuremath{\alpha}+(Pb and C) collisions at 400 MeV/nucleon. The coalescence relation between protons and deuterons was examined for the inclusive part of the spectra. The size of the interacting region was evaluated from the observed coalescence coefficients. The rms radius is typically 4--5 fm, depending of the target mass. The proton and deuteron energy spectra corresponding to central collisions were fitted assuming emission from a single source moving with a velocity intermediate between that of the projectile and the target. The extracted ``temperatures'' are independent of the nature of the emitted particle, indicating that the fragments have a common source. The best fits were achieved for 200- and 400-MeV/nucleon reactions. Spectra of deuteron-like pairs, including real deuterons and neutron-proton pairs that may be contained in a larger nuclear cluster, are compared to the prediction of an intranuclear cascade model incorporating a clustering algorithm based on a classical coalescence prescription. Best agreements between experimental and predicted deuteron-like spectra occur for 800- and 600-MeV/nucleon collisions.

Charged pions and light nuclei ({ital p}, {ital d}, {ital t}, {sup 3}He, and {sup 4}He) have been measured in the interaction of proton beams with C, Nb, and Pb targets at 0.8 and 1.6 GeV incident energies, using a large solid angle detector. From slices on the multiplicity of protonlike particles (free protons and protons bound in light fragments), the events have been sorted out into two classes corresponding to more peripheral and more central collisions. For each class of events, the mean value and the dispersion of the {pi}{sup +} and {pi}{sup {minus}} multiplicity distributions have been studied as a function of target mass and incident energy. Comparisons to the Liege intranuclear cascade predictions exhibit some discrepancies which are discussed.

A simple method is proposed for determining the impact parameter in relativistic nucleus-nucleus collisions. Assuming a monotonous correlation between multiplicity and impact parameter, the multiplicity dependence of the measured cross section is interpreted as an impact-parameter dependence of the geometrical reaction cross section. The reliability of this method is checked to be excellent within the framework of the intranuclear cascade model. Its application to data analysis at lower and higher energies is suggested.

In order to study the nuclear collective flow, the triple differential momentum distributions of charged baryons are fitted to a simple anisotropic gaussian distribution, within an acceptance which removes most of the spectator contribution. The adjusted flow angle and aspect ratios are corrected for systematic errors in the determination of the reaction plane. This method has been tested with Monte Carlo simulations and applied to experimental results and intranuclear cascade simulations of argon-nucleus collisions at 400 MeV per nucleon.

Charge distributions at fixed mass asymmetry are presented. Their widths seem to be due to classical statistical fluctuations. If a contribution by quantal fluctuations of the giant E1 mode is present, the inertia of this mode must have increased to very large values.

Mass distributions of evaporation residues from the fusion of 63Cu + 65Cu have been measured at seven excitation energies from 55 to 105 MeV in a single irradiation experiment. They are interpreted as a mixture of residues produced by single nucleon evaporation cascades and cascades including α-particle evaporation. Compound nuclei with an average excitation energy of 55 MeV ( 51.5 ≦ E ∗ ≦ 59 MeV ) are still found to have a probability as high as 0.3 % for decaying by emission of a single nucleon. The low-energy behaviour of the excitation function can be interpreted as a fusion barrier effect. The parameters of this barrier are determined. The evaporation residue cross section at higher energies is shown to be limited by the fission of the compound nucleus.

Diogene, an electronic 4 pi detector, has been built and installed at the Saturne synchrotron in Saclay. The forward angular range (0 degree-6 degrees) is covered by 48 time-of-flight scintillator telescopes that provide charge identification. The trajectories of fragments emitted at larger angles are recorded in a cylindrical 0.4-m3 Pictorial Drift Chamber (PDC) surrounding the target. The PDC is inside a 1-T magnetic field; the axis of the PDC cylinder and the magnetic field are parallel to the beam. Good identification has been obtained for both positive and negative pi mesons and for hydrogen and helium isotopes. Multiplicities in relativistic nucleus-nucleus reactions up to 40 have been detected, limited mainly by the present electronics.

The cross sections for production of evaporation residues (σ er) and for fusion-fission (σ ff) have been measured for40Ar+144, 148, 154Sm at sub-barrier energies by observation of x-ray emission from radioactive products and by direct,ΔE−E identification of fission fragments, respectively. These isotopes span the transition region from spherical (144Sm) to strongly deformed (154Sm) equilibrium shapes. The cross section for fusion,σ fus=σ er+σ ff, is found to vary markedly at low energies with the isotope number and, hence, with the quadrupole collectivity of the target. The thresholds for fusion of148Sm and144Sm are, respectively, ∼3.5 MeV and ∼7 MeV (c.m.) higher than for fusion with154Sm. These differences and the energy dependence of the fusion cross sections are discussed in terms of the effect of nuclear deformation on heavy-ion fusion. A comparative analysis of results for16O+Sm and40Ar+Sm in terms of static deformation indicates thatσ fus for the Ar+Sm system at very low energies is enhanced relative to the prediction for a one-dimensional barrier based on a fit toσ fus for16O+Sm. This may be an indication that additional degrees of freedom (such as formation of a neck or fragment elongation) may be important for fusion with the larger projectile. At energies above the fusion barrier, values ofσ fus for144, 148Sm are nearly equal, but are significantly smaller than for154Sm. This is in contrast to the results of previous experiments with16O projectiles in whichσ fus (16O+148Sm) andσ fus (16O+154Sm) were nearly equal above the barrier. These differences, observed for144, 148Sm and154Sm at energies above the barrier may reflect a new mechanism which is not encompassed by a static theory.

The rather small size of the Diogene pictorical drift chamber has several unfavourable consequences: not more than 16–18 points to define even the best isolated tracks; high track density and hence missed points due to double hit resolution; strongly bent trajectories and thus many track crossings. In spite of these difficulties, the events can be analyzed. The program takes advantage of the fact that the vertex position is known. Two different methods are used: the first one selects out rather quickly most of the tracks by a simple strategy; the remaining tracks are then searched by a more global but much more time consuming method.

Angular distributions for fission-like fragments were measured in the systems 50Ti, 56Fe + 208Pb by applying an off-line K X-ray activation technique. The distributions d2σ/dθdZ exhibit forward-backward asymmetries that are strongly Z-dependent. They result from a process (quasi-fission) which yields nearly symmetric masses in times comparable to the rotational period of the composite system. A method for obtaining the variance of the tilting angular momentum, K02, from these skewed, differential angular distributions is described. The results indicate that the tilting mode is not fully excited in quasi-fission reactions. The results are compared to the sum of the variances of all statistical spin components, measured via γ-multiplicities. Integration of the angular distributions d2σ/dθdZ over all values of Z yields the integral angular distributions dσ/dθ and dσ/dΩ symmetric around 90°. The associated unusually large anisotropies do not at all provide an adequate basis for tests or modifications of the transition-state theory. A deconvolution of d2σ/dθdZ is performed with gaussian distributions depending on rotational angles Δθ extending over a range of up to 540°. From the mean values 〈Δθ〉 a time scale for the evolution of K0 is calculated.

Some results on the charge equilibration process for the 205 Pb (1550 MeV) + 74 Ge and 86 Kr (550 MeV) + 197 Au reactions obtained by on-line measurements are discussed and compared with the previous results of the 132 Xe (890 MeV) + 197 Au reaction investigated using radiochemical techniques. In all cases global and isobaric charge widths were measured as a function of the excitation energy. It is shown that the corrections associated with both the evaporation process and the experimental mass or charge resolution are most important in obtaining correct primary distributions. The results confirm a preferential neutron exchange at the beginning of the reaction, as was suggested by the Brosa and Gross model. Further attempts to analyse the data with existing dynamical models have not succeeded in their present stage of development in discriminating between the assumptions of statistical versus quantal fluctuations as observed in the study of the Kr + Mo system.

Inclusive proton-induced charged pion production was studied on 12 C, 89 Y and nat Pb at 201 and 180 MeV. A QQD spectrometer was used for forward angles and a plastic scintillator range spectrometer for backward angles. The angular dependence, variation with the pion energy, and total cross sections are deduced from doubly differential cross section measurements.

Excitation functions of evaporation residues following compound nucleus formation in heavy ion reactions have been measured with a single 6 h irradiation of a thick target. The separation of the reaction products as a function of their initial excitation energy is achieved by selecting them according to their recoil energy in a stack of thin catcher foils. The evaporation residues are identified by off-line X-ray and γ-ray measurements of their radioactive decay. The combined irradiation and X-ray - γ-ray technique can be used to study reactions which could hardly be investigated by standard on-line measurements.

The capture and detection processes of neutrons in large gadolinium loaded liquid scintillators have been simulated using a Monte-Carlo program. The capture efficiency and also the probability of detecting a captured neutron depend on the initial energy of the neutron. The influences of the size of the tank and the location of the source are studied. It is shown that any increase of the efficiency leads to smaller variations of both the capture and γ detection probabilities over the energy range.

The nuclear reactions induced by 273 MeV 40 Ar ions on a 159 Tb target have been studied using recoil techniques and off-line X-ray spectrometry. The heavy products from fusionevaporation, fusion-fission, and transfer reactions can easily be separated on the basis of charge identification by X-ray spectrometry. The corresponding angular and range distributions are typical of each process. For each value of the atomic number, the average mass of the evaporation residues was determined with an uncertainty of ± 2 mass units (i.e.±1 %). The data were consistent with the assumption that 9±2 particles (nucleon and possibly some α-particles) were evaporated by the compound nucleus. The range measurements give results which agree with calculated values based on the total momentum transfer hypothesis within ± 8 %. The c.m. angular and energy distributions of transfer reaction products are typical of deep inelastic transfer reactions, with a contribution from partially damped events. The comparison of experimental data with the results of a calculation based on the model of Ngoˆand Hofmann in which statistical fluctuations are explicitly taken into account, indicates that the model reproduces correctly the position of the angular distribution maxima, for one- and two-charge transfer reactions, but underestimates the width of the angular distributions. Moreover, no transfer of more than two charges from the projectile to the target is predicted by this model while significant cross sections are observed experimentally.

A stacked foil technique and radioehemical yield measurements were combined in order to study the reaction of 132 Xe ions with 197 Au at 1.3 times the interaction barrier energy. Evidence is presented for a preferential exchange of neutrons for energy losses of up to 100 MeV. The same amount of energy damping is required for the development of a drift in the position of the centroid of the element distribution and for the evolution of full correlations in the exchange of neutrons and protons. The widths of the charge distributions at fixed mass asymmetry rise slowly as the degree of energy damping increases. This is reminiscent of classical statistical fluctuations, although the widths at large excitation energies have also been reproduced quantum-mechanically in terms of the zero-point motion of a collective isovector mode analogous to the giant dipole resonance in spherical nuclei. All results concerning the initial evolution of charge and mass distributions seem to be dominated by a hindrance of proton exchanges for large internuclear distances.

An evaluation method is presented which allows reconstruction of primary (pre-evaporation) yield distributions from secondary (post-evaporation) measured quantities. The width of the energy distribution is explicitly taken into account in the calculations and can be extracted from the mass dependence of the kinetic energy loss of the reaction products for a fixed Z value. This method is applied to radiochemical measurements of reaction products from 132 Xe + 197 Au collisions.

Angular distributions and integral cross sections for heavy reaction products from84Kr +238U collisions at 522 MeV were measured using catcher foil techniques and off-line X-ray identification of individual reaction product isotopes. There is no evidence for a fission-fusion mechanism being responsible for the formation of the “gold finger”. The data show that usual deep inelastic collisions account for the formation of all products with 70≦Z≦86. Compared to existing data atE≦605 MeV, the deduced mass distribution indicates reduced fission probabilities forZ≧80 fragments at 522 MeV. This is consistent with the expected dependence of fission probability on excitation energy and especially on angular momentum.

Long-range $\ensuremath{\alpha}$-accompanied fission of $^{252}\mathrm{Cf}$ is investigated in a five-parameter correlation experiment and the behavior of each component of total energy, including the prompt neutrons from the individual fragments, as well as from the fragment pairs and the prompt-$\ensuremath{\gamma}$ emission, is studied and compared with the binary fission. The problem of determining the nucleon contribution by binary fragments to the $\ensuremath{\alpha}$-particle formation is discussed. The average energy of the $\ensuremath{\alpha}$ particle is observed to increase towards the symmetric fission region, which is understood in terms of a possible shift of the scission point towards the heavy fragment. The dependence of the average number of total neutrons on the $\ensuremath{\alpha}$-particle energy and the dependence of the $\ensuremath{\alpha}$-particle energy on the fragment total kinetic energy is not linear, which is interpreted to yield some qualitative information on the initial energy of the $\ensuremath{\alpha}$ particle. Several differential correlations are also discussed.

An experimental method checking the reliability of ν measurements has been tested. Results lead to a σv2 value for 252Cf lower than those published by others. The so-called “French effect” is investigated as a function of the scission mode.

A multiparameter experiment in which the kinetic energies of the fragments, the number of prompt fission neutrons and the total γ-ray energy per fission were measured, has been performed. The neutron multiplicity and the γ-ray measurements were made with the same large scintillator. A method which corrects the γ-pulse for the proton recoils caused by the fission neutrons is described. The results show that the γ-energy decreases by about 0.1 MeV when the total kinetic energy of the fragments increases by 1 MeV. A linear relationship between the γ-ray energy emitted by a given fragment and the average number of neutrons emitted by the same fragment is suggested, namely: Eγ(m, Et) = 0.75− ν (m, Et) + 2 (MeV). These results are interpreted as caused by a linear increase of the average spin of the fragments with their excitation energy.

The correlation between the excitation energies of complementary fission fragments has been determined as a function of mass ratio. Contrary to results published by other authors the present data show that these energies are completely uncorrelated for most mass pairs.

Proton-proton small angle correlations have been measured in neon-nucleus collisions, using the 4 pi detector Diogene, at 400 and 800 MeV per nucleon incident energies. Values of the size of the emitting region are obtained by comparison with the Koonin formula, taking into account the biases of the apparatus. The dependence of the density on target mass and incident energy is also analysed.

The collective flow measurements presented in this lecture have been performed with the DIOGENE electronic 4π-detector1 installed at the Saturne synchrotron in Saclay, which can deliver beams up to mass 40. In order to study the properties of dense (and hot) nuclear matter, it is required to measure nucleus-nucleus collisions involving a large number of nucleons That is the reason why we focused our experiment on asymmetric collisions,, with target nuclei heavier than the beam.

Cross sections for the production of π + and π − have been measured over a wide range of angles for 12 C + 7 Li, 12 C + 12 C and 12 C + 208 Pb collisions at 60 A , 75 A and 85 A MeV. Energy distributions are less steep and absolute yields of pions larger than expected from a straightforward Fermi gas nucleon-nucleon scattering prescription. The apparent velocity of the system in which the π + emission is symmetric, is closer to the nucleus-nucleus c.m. velocity than to the mean speed system. The Coulomb-corrected π − π + ratio is close to unity for 12 C + 12 C. The corresponding ratio for 12 C + 208 Pb is, however, much larger than expected from the neutron excess in 208 Pb only.