X-ray investigations of La2CuO4 and Pr2CuO4 under high pressure

X-ray investigations of Pr2CuO4 and La2CuO4 under pressure have been carried out at 300 K and 30 K. The lattice parameters decrease monotonically for both structures, thus preserving the structure of the materials. For La2CuO4 the lattice parameter reduction is isotropic with increasing pressure, but the lattice parameters of Pr2CuO4 are found to behave anisotropic, as the c-axis decreases faster than the a-axis. La2CuO4 has a bulk modulus of 1850 kbar at 300 K, whereas Pr2CuO4 has a bulk modulus of 1600 kbar at 300 K and 1650 kbar at 30 K, due to the faster decreasing c-axis lattice parameter. In the a and b direction both materials have a similar compressibility. Assigning this behaviour to the common copper-oxide layers of both structures gives the possibility to generalize these results. For several high temperature superconductors we estimated the linear compressibilities in the a, b direction being in the range of 1.5 to 2.0×10-4 kbar-1. In the c-direction the compressibility apparently depends on the degeneracy of the oxygen octahedra and the number of intercalated layers orstructural elements. © 1989

X-ray investigations of La2CuO4 and Pr2CuO4 under high pressure

X-ray investigations of Pr CuO and La CuO under pressure have been carried out at 300 K and 30 K. The lattice parameters decrease monotonically for both structures, thus preserving the structure of the materials. For La CuO the lattice parameter reduction is isotropic with increasing pressure, but the lattice parameters of Pr CuO are found to behave anisotropic, as the c-axis decreases faster than the a-axis. La CuO has a bulk modulus of 1850 kbar at 300 K, whereas Pr CuO has a bulk modulus of 1600 kbar at 300 K and 1650 kbar at 30 K, due to the faster decreasing c-axis lattice parameter. In the a and b direction both materials have a similar compressibility. Assigning this behaviour to the common copper-oxide layers of both structures gives the possibility to generalize these results. For several high temperature superconductors we estimated the linear compressibilities in the a, b direction being in the range of 1.5 to 2.0×10 kbar . In the c-direction the compressibility apparently depends on the degeneracy of the oxygen octahedra and the number of intercalated layers orstructural elements. © 1989. 2 4 2 4 2 4 2 4 2 4 2 4 -4 -

T-cs tests and performance assessment of the ITER Toroidal Field ModelCoil (Phase II)

The tests of the Toroidal Field Model Coil (TFMC) were completed in 2002 in the TOSKA facility of Forschungszentrum Karlsruhe, Germany. Operation reached a combined 80 kA in the TFMC and 16 kA in the LCT coil, resulting in a peak electromechanical load very close to that expected in the full-size ITER TF coils (800 kN/m). Here we concentrate on the measurements of the current sharing temperature (T-cs) of the TFMC conductor, possibly the highlight of the whole test campaign. These tests were performed by increasing in steps the helium inlet temperature T-in in double pancake DP1, resulting in an increasing normal voltage V across the DP1.1 and DP1.2 conductors, and were repeated for several combinations of currents in the TFMC and in the LCT coil. The analysis of the V - T-in characteristic by means of the M&M code allows to self-consistently deriving an estimate of T-cs, as well as an indirect assessment of the "average" strain state in the conductor. The TFMC isolated strand has also been very recently characterized at different applied uniaxial strain, and preliminary results indicate a stronger reduction of carrying capacity compared to the extrapolation from Summers scaling used in the analysis so far. As a consequence, the performance of the TFMC conductor, as preliminarily re-evaluated here, appears more in line with the strand performance than in previous analysis, although a BI-dependent "degradation" is still present

Overview of Progress on the EU DEMO Reactor Magnet System Design

The DEMO reactor is expected to be the first application of fusion for electricity generation in the near future. To this aim conceptual design activities are progressing in Europe (EU) under the lead of the EUROfusion Consortium in order to drive on the development of the major tokamak systems. In 2014 the activities carried out by the magnet system project team were focused on the Toroidal Field (TF) magnet system design and demonstrated major achievements in terms of concept proposals and of consolidated evaluations against design criteria. Several magnet system R&D activities were conducted in parallel, together with broad investigations on High Temperature Superconductor (HTS) technologies. In this paper we present the outcomes of the work conducted in two areas in the 2014 magnet work program: (1) the EU inductive reactor (called DEMO1) 2014 configuration (power plant operating under inductive regime) was the basis of conceptual design activities, including further optimizations; and (2) the HTS R&D activities building upon the consolidated knowledge acquired over the past years