An assessment of the evaporation and condensation phenomena of lithium during the operation of a Li(d,xn) fusion relevant neutron source.

The flowing lithium target of a Li(d,xn) fusion relevant neutron source must evacuate the deuteron beam power and generate in a stable manner a flux of neutrons with a broad peak at 14 MeV capable to cause similar phenomena as would undergo the structural materials of plasma facing components of a DEMO like reactors. Whereas the physics of the beam-target interaction are understood and the stability of the lithium screen flowing at the nominal conditions of IFMIF (25 mm thick screen with +/-1 mm surface amplitudes flowing at 15 m/s and 523 K) has been demonstrated, a conclusive assessment of the evaporation and condensation of lithium during operation was missing. First attempts to determine evaporation rates started by Hertz in 1882 and have since been subject of continuous efforts driven by its practical importance; however intense surface evaporation is essentially a non-equilibrium process with its inherent theoretical difficulties. Hertz-Knudsen-Langmuir (HKL) equation with Schrage's 'accommodation factor' η = 1.66 provide excellent agreement with experiments for weak evaporation under certain conditions, which are present during a Li(d,xn) facility operation. An assessment of the impact under the known operational conditions for IFMIF (574 K and 10-3Pa on the free surface), with the sticking probability of 1 inherent to a hot lithium gas contained in room temperature steel walls, is carried out. An explanation of the main physical concepts to adequately place needed assumptions is included.

Operation and commissioning of IFMIF (International Fusion Materials Irradiation Facility) LIPAc injector.

The objective of linear IFMIF prototype accelerator is to demonstrate 125 mA/CW deuterium ion beam acceleration up to 9 MeV. The injector has been developed in CEA Saclay and already demonstrated 140 mA/100 keV deuterium beam [R. Gobin et al., Rev. Sci. Instrum. 85, 02A918 (2014)]. The injector was disassembled and delivered to the International Fusion Energy Research Center in Rokkasho, Japan. After reassembling the injector, commissioning has started in 2014. Up to now, 100 keV/120 mA/CW hydrogen and 100 keV/90 mA/CW deuterium ion beams have been produced stably from a 10 mm diameter extraction aperture with a low beam emittance of 0.21 π mm mrad (rms, normalized). Neutron production by D-D reaction up to 2.4 × 10(9) n/s has been observed in the deuterium operation.

[Parotid schwannoma]. / Schwannoma parotídeo.

We present the case of a 13-year-old boy with intra-parotid schwannoma of the facial nerve. We discuss the histopathology, preoperative diagnosis by fine needle aspiration cytology, and surgical strategy.

[Hypothesis on the mechanism of development of some forms of tinnitus. Therapeutic orientation of them]. / Hipótesis sobre el mecanismo de formación de algunos acúfenos. Orientación terapéutica de los mismos.

The author believes that many forms of tinnitus are caused by a functional alteration in the efferent fibers of Ramussen, Galambos and Portmann. Due to the fact of this functional alteration, the noise is not stopped by this filter and the patient has acoustic impressions caused by organic noises, probably vascular noises in the temporal bone. There is also reported an important improvement in subjective disturbances with personal auditory training.