A novel mobile XRF scanner combining MA-XRF and micro-XRF techniques and allowing near real-time elemental imaging of macroscopic paintings.

Breakup temperatures were deduced from double ratios of isotope yields for target spectators produced in the reaction 197 The good agreement with the breakup temperatures measured previously for projectile spectators at an incident energy of 600 MeV per nucleon confirms the universality established for the spectator decay at relativistic bombarding energies. The measured temperatures also agree with the breakup temperatures predicted by the statistical multifragmentation model. For these calculations a relation between the initial excitation energy and mass was derived which gives good simultaneous agreement for the fragment charge correlations.The energy spectra of light charged particles, measured at θ lab = 150• , exhibit Maxwellian shapes with inverse slope parameters much higher than the breakup temperatures. The statistical multifragmentation model, because Coulomb repulsion and sequential decay processes are included, yields light-particle spectra with inverse slope parameters higher than the breakup temperatures but considerably below the measured values. The systematic behavior of the differences suggests that they are caused by light-charged-particle emission prior to the final breakup stage. Keywords:197 Au projectiles and targets, E/A = 600 and 1000 MeV; measured fragment cross sections, isotopic yield ratios; deduced breakup temperatures, pre-breakup emission; analysis using quantum statistical and statistical multifragmentation models.

Pinhole and CCD based quasi-optical X-ray imaging technique was applied to investigate the plasma of an Electron Cyclotron Resonance Ion Source. Spectrally integrated and energy resolved images were taken from an axial perspective. The comparison of integrated images taken of argon plasma highlights the structural changes affected by some ECRIS setting parameters, like strength of the axial magnetic confinement, RF frequency and microwave power. Photon counting analysis gives precise intensity distribution of the X-ray emitted by the argon plasma and by the plasma chamber walls. This advanced technique points out that the spatial positions of the electron losses are strongly determined by the kinetic energy of the electrons themselves to be lost and also shows evidences how strongly the plasma distribution is affected by slight changes in the RF frequency.

Breakup temperatures in central collisions of 197 Au 1 197 Au at bombarding energies E͞A 50 to 200 MeV were determined with two methods. Isotope temperatures, deduced from double ratios of hydrogen, helium, and lithium isotopic yields, increase monotonically with bombarding energy from 5 to 12 MeV, in qualitative agreement with a scenario of chemical freeze-out after adiabatic expansion. Excited-state temperatures, derived from yield ratios of states in 4 He, 5,6 Li, and 8 Be, are about 5 MeV, independent of the projectile energy, and seem to reflect the internal temperature of fragments at their final separation from the system. [ S0031-9007(98) . The temperatures were derived from double ratios of helium and lithium isotopic yields while the excitation energies were obtained by adding up the kinetic energies of the product nuclei and the mass excess of the observed partition with respect to the ground state of the reconstructed spectator nucleus. The double-bended shape of the caloric curve and its similarity to predictions of microscopic statistical models [2][3][4], has stimulated considerable experimental and theoretical activities. In particular, the second rise of the temperature to values exceeding 10 MeV at high excitation energies has initiated the discussion of whether nuclear temperatures of this magnitude can be measured reliably (see , and references given in these recent papers) and whether this observation may indeed be linked to a transition towards the vapor phase [7,8]. Obviously, a well-founded understanding of the significance of the employed temperature observables [9] is indispensable when searching for signals of the predicted liquid-gas phase transition in nuclear matter.Here, we present the results of temperature measurements for central collisions of 197 Au 1 197 Au at incident energies E͞A 50 to 200 MeV. These collisions are characterized by a collective radial flow of light particles and fragments which, over the covered energy range, evolves as a dynamical phenomenon closely connected to the initial stages of the reaction [10]. Global equilibrium is clearly not achieved. If local equilibrium is reached, the associated temperatures should reflect the adiabatic cooling of the rapidly expanding system. Two temperature observables were used simultaneously. Isotope temperatures were deduced from double ratios of isotopic yields [11] and excited-state temperatures were derived from the correlated yields of lightparticle coincidences [9,12,13]. It will become evident from the diverging results that this represents more than a methodical test and that the two types of thermometers are sensitive to different stages of the fragment formation and emission.Beams of 197 Au with E͞A 50, 100, 150, and 200 MeV, provided by the heavy-ion synchrotron SIS, were directed onto targets of 75 mg͞cm 2 areal density. Two multidetector hodoscopes, consisting of 96 and of 64 Si-CsI(Tl) telescopes in closely packed geometries, were placed on opposite sides with respect to the beam axis. Four high-resolution te...

This work describes a tabletop (50 cm × 25 cm × 25 cm) full field X-ray pinhole camera (FF-XPC) presenting high energy- and high spatial-resolution. The FF-XPC consists of a conventional charge-coupled device (CCD) detector coupled, in a coaxial geometry, to a pinhole collimator of small diameter. The X-ray fluorescence (XRF) is induced on the samples with an external low-power X-ray tube. The use of the CCD as an energy dispersive X-ray detector was obtained by adopting a multi-image acquisition in single photon counting and by developing a processing algorithm to be applied in real-time to each of the acquired image-frames. This approach allowed the measurement of X-ray spectra with an energy resolution down to 133 eV at the reference value of 5.9 keV. The detection of the X-ray fluorescence through the pinhole-collimator allowed the two-dimensional elemental mapping of the irradiated samples. Two magnifications (M), determined by the relative sample-pinhole-CCD distances, are used in the present setup. A low value of M (equal to 0.35×) allows the macro-FF-XRF of large area samples (up to 4 × 4 cm(2)) with a spatial resolution down to 140 μm; a large magnification (M equal to 6×) is used for the micro-FF-XRF of small area samples (2.5 × 2.5 mm(2)) with a spatial resolution down to 30 μm.