[en] Disclosed is a method and apparatus for providing pathways for electrical conductors and conduits through radiation shielding without effectively diminishing the degree of shielding. A pathway is formed by providing a helical groove on the surface of a cylindrical shielding member which is fitted with close tolerance inside a tubular housing. Specific embodiments provide for the passage of electrical conductors through a cylinder of shielding material positioned within a well logging sonde between a radiation source and a radiation detector. One or more grooves may be provided in the shielding member. The shielding member may be constructed of two or more individual, coaxially aligned, abutting, cylindrical shielding submembers. The shielding submembers making up a shielding member may be of the same or different shielding material

[en] Several Toroidal Field Conductor short samples with slight layout variations have been assembled and tested in the SULTAN facility at CRPP. The measurement campaigns started in 2007 and are still ongoing. The performance of every conductor is expressed in terms of current sharing temperature (T_cs), i.e. the temperature at which a defined electric field, 10 μV/m, is detected in the cable due to the incipient superconducting-to-normal state transition. The T_cs at specific operating conditions is the key design parameter for the ITER conductors and is the main object of the qualification tests. Typically, the average electric field is measured with voltage tap pairs attached on the jacket along the conductor. The inability however to explain observed premature voltage developments opened the discussion about possible alternative measuring methods. The He flow calorimetric method is based on the measurement of the resistive power generation in the conductor. It relies on the detection of very small temperature increases along the conductor in steady state operation. The accuracy and the reliability of the calorimetric method in SULTAN are critically discussed, with particular emphasis on the instrumentation requirements and test procedures. The application of the calorimetric method to the recent SULTAN test campaigns is described with its merits and limits. For future tests of ITER conductors in SULTAN, the calorimetric method for T_cs test is proposed as a routine procedure.

[en] In the present investigation some surface markers in peripheral blood T lymphocytes of patients with active Graves' disease and subjects in remission after ¹³¹I-therapy have been studied. We confirmed low TG levels in untreated patients and normal values in treated subjects. Increased percentages of DR+, MLR4+ (activated T cells), and 5/9+ (inducer-helper) T cells were detected in patients with active disease, thus indicating the presence of activated T cells and suggesting increased levels of helper T cells. High percentages of MLR4+ and 5/9+, but normal levels of DR+ were found in ¹³¹I-treated subjects. The different distribution of DR and MLR4 positivities on 5/9+ and 5+9-T cells confirm the different meaning of these two markers of the activation state. The imbalance of T-cell subsets found in ¹³¹I-treated subjects and the normal values observed in patients with hyperthyroidism due to toxic adenoma indicate that hyperthyroidism per se is not sufficient to explain the T-cell alterations. The possible meaning of these findings is discussed with respect to previous hypotheses on the pathogenesis of Graves' disease

[en] Glutathione (GSH) and synthetic aminothiols, such as N-acetylcysteine (NAC), play an important role as inhibitors of mutagenesis and carcinogenesis. The present paper updates the studies carried out in the authors' laboratories, which are discussed according to a mechanistic approach. In Table 1, reporting the classification of inhibitors of mutagenesis and carcinogenesis proposed by De Flora and Ramal, the arrows indicate the mechanisms that they have investigated so far in the case of aminothiols. 38 refs., 6 figs., 1 tab

[en] We present a new multi-solid multi-channel (M³) thermal-hydraulic model for the analysis of the International Thermonuclear Experimental Reactor (ITER) Cable-In-Conduit Conductors (CICC). The model discretizes the cross section of an ITER CICC into M current carrying cable elements (e.g., the six last-but-one cabling stages-the petals), coupled with N hydraulic channels (e.g., the six petals + the central channel) and K non-current carrying solid components (e.g., the jacket of the CICC), with M, N and K arbitrary integers. Along each of the M + K solid components a 1D transient heat conduction equation is solved, whereas along each of the N channels three Euler-like 1D equations, derived from the conservation laws for compressible He flow, are solved. The resulting quasi 3D model, in which 1D equations are coupled by heat and mass transfer between the different CICC components, is implemented in the M³ code and validated against experimental results from the ITER Good Joint sample and the ITER Poloidal Field Conductor Insert Full Size Joint Sample. The new code is able to reproduce with good accuracy the measured temperature gradients on the CICC cross section, provided sufficiently accurate input data are available

[en] The International Thermonuclear Experimental Reactor (ITER) Toroidal Field Model Coil (TFMC) was tested in the Toska facility of Forschungszentrum Karlsruhe during 2001 (standalone) and 2002 (in the background magnetic field of the LCT coil). The TFMC is a racetrack coil wound in five double pancakes on stainless steel radial plates using Nb3Sn dual-channel cable-in-conduit conductor (CICC) with a thin circular SS jacket. The coil was cooled by supercritical helium in forced convection at nominal 4.5 K and 0.5 MPa. Instrumentation, all outside the coil, included voltage taps, pressure and temperature sensors, as well as flow meters. Additionally, differential pressure drop measurement was available on the two pancakes DP1.1 and DP1.2, equipped with heaters.Two major thermal-hydraulic issues in the TFMC tests will be addressed here: 1) the pressure drop along heated pancakes and the comparison with friction factor correlations; 2) the quench initiation and propagation. Other thermal-hydraulic issues like heat generation and exchange in joints, radial plates, coil case, or the effects of the resistive heaters on the helium dynamics, have been already addressed elsewhere

[en] All the ITER superconductors are tested as short length samples in the SULTAN test facility at CRPP. Twenty-four TF conductor samples with small layout variations were tested since February 2007 with the aim of verifying the design and qualification of the manufacturers. The sample assembly and the measurement techniques at CRPP are discussed. Starting in 2010, another test facility for ITER conductors, named EDIPO, will be operating at CRPP to share with SULTAN the load of the samples for the acceptance tests during the construction of ITER.

[en] A short sample of the NbTi cable-in-conduit conductor (CICC) manufactured for the ITER PF insert coil has been tested in the SULTAN facility at CRPP. The short sample consists of two paired conductor sections, identical except for the sub-cable and outer wraps, which have been removed from one of the sections before jacketing. The test program for conductor and joint includes DC performance, cyclic load and AC loss, with a large number of voltage taps and Hall sensors for current distribution. At high operating current, the DC behavior is well below expectations, with temperature margin lower than specified in the ITER design criteria. The conductor without wraps has higher tolerance to current unbalance. The joint resistance is by far higher than targeted. (authors)

[en] TFAS1 (Toroidal Field Advanced Strand) sample is composed of two Nb₃Sn cable-in-conduit conductors intended to be used in ITER Toroidal Field Coils. This sample was tested in the SULTAN facility in order to benchmark the performance in years 2005-2006. An early voltage evolution was observed in both conductors during current ramp up, which makes it difficult to assess correctly the conductor performance. In order to improve the voltage behavior, the two terminations and two halves of the joint were filled by solder at CRPP with the aim to achieve a more uniform current distribution in the conductors. Thereafter, the TFAS1 sample was retested in the SULTAN facility. The retest revealed an unexpected increase of resistance after solder filling at the conductor extremities. As a consequence the voltage slope did not disappear, and further reduction of conductor performance was observed. The results of the retest of the TFAS1 sample with solder filled extremities are presented and discussed in this paper. (authors)

[en] A first validation of the full version of the thermal-hydraulic electromagnetic (THELMA) code, developed for the analysis of transients in the cable-in-conduit conductors and coils relevant for the International Thermonuclear Experimental Reactor (ITER) is presented here. THELMA includes electromagnetic models of the cable joints and terminations (lumped parameter) and of the conductor (distributed parameter), while for the thermal-hydraulics of the helium coolant it includes a compressible 1D flow model. The AC losses induced by a pulsed coil in the NbTi poloidal field full size joint sample (PF-FSJS) right leg conductor, tested in 2002 at the Sultan facility in Villigen (CH), are considered as test bed for this exercise. The computed energy deposition and evolution of the temperature downstream of the heated zone are in good agreement with the measured values. However, the inter-bundle electrical conductances needed in input by the code are compatible with measured values only when a sufficiently refined model is used in the cable cross-section