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The activities in Europe towards the development of the EC power sources for ITER are centered on the development of a 170GHz, 2MW, CW coaxial cavity gyrotron of collector potential depressed (CPD) type. A gyrotron with a higher unit power than the ITER reference (I MW) would yield a reduction of the installation costs, a more compact launcher design and, if required, an increase of the power delivered through one port. Tests proving the principle were successfully performed on a short-pulse experimental gyrotron delivering up to 2.2 MW in single mode. Following this success, a coordinated and fully consistent programme of development has been launched. The first industrial 2 MW prototype is now at an advanced stage of construction. The associated superconductive magnet producing 6.86 T on the cavity axis is also being procured. Dummy loads suitable for short and CW operation are also part of the development effort. Finally, a new EC test facility, with the features necessary for the testing of the gyrotron up to full power in CW, has been established and includes a fully solid-state power supply system. (c) 2007 Published by Elsevier B.V.

A cable in conduit superconducting magnet for an MHD experimental linear generator is under construction at Ansaldo workshop in Genova. A unique technique that doesn't require the winding form has been adopted for the coils fabrication; it will allow the construction of large size MHD magnets. In the following, after a brief description of the constructive details of the components of this 5 T, 62 MJ magnet, we report a description of the fabrication technique, of the experience gained during the manufacturing and the characteristics of the obtained product. >

Ansaldo Componenti is carrying out the design of a superconducting dipole magnet to be employed in an experimental MHD (magnetohydrodynamic) generator. The magnet is a rectangular saddle-shaped dipole with an on-axis field of 5 T, an active length of 2 m, a 0.7*0.5 m warm bore, and a stored energy of 62 MJ. It will be the first MHD magnet wound by a cable-in-conduit superconductor; this choice was made in order to employ a conductor concept and a technology scalable to larger-size MHD magnets. The main aspects of the superconductive and mechanical design are reported. >

The thin solenoid for the Zeus detector has been installed and tested in HERA (Hadron Electron Ring Accelerator) at DESY. The coil reached the design magnetic field (1.8 T in the center) without training. During the test some measurements were made in order to investigate the cooling system and the quench-back behavior. No spontaneous quenches occurred. Several induced fast discharges showed the evidence of a quench-back effect, and the quench-back starting time was less than 1 s. The cylinder temperature measurements during the coil discharge perfectly agree with adiabatic calculations. The indirect cooling efficiency was verified for the two-layer winding. The tests performed showed that the magnet can operate safely at the nominal field.

A bath-cooled superconducting solenoid with a 280-nm-diameter warm bore, a coil length of 1200 mm, and a central field of 5 T at the rated current of 950 A has been built. It will operate as the compensating coil inside the Zeus detector at HERA (the Hadron Electron Ring Accelerator) at Desy. The coil is shielded by a 3.5-ton low carbon steel cold yoke, and the cold helium chamber was designed to withstand a maximum pressure of 20 bar. The main results obtained during the cool down and energization are reported.

The next generation neutrino mass experiment KATRIN (Karlsruhe Tritium Neutrino experiment) uses a series of superconducting magnet systems, which guide the electrons from tritium beta-decay adiabatically from the source to the detector within a magnetic flux of 0.0191 . The electron transport and tritiuAm pumping sections contain two complex magnet systems; the Differential Pumping Section (DPS2-F) and the Cryogenic Pumping Section (CPS) that are designed with a central magnetic flux density from 5 T to 5.7 T for persistent-mode operation. Each system has a series of superconducting solenoids in a zigzag arrangement that is designed to enhance the tritium pumping efficiency. The 7 m long DPS2-F was commissioned at the end of 2010 and the magnetic performance of the DPS2-F was accepted for the KATRIN experiment. The DPS2-F was operated for more than 325 hours in persistent-mode to investigate long term field stability, which is required to stay within 0.01% at the nominal field for a 60-day measurement run. All seven modules of the CPS were manufactured and successfully cold-tested.

A thin superconducting solenoid of 0.76 m in internal diameter and 0.8 m in length has been manufactured and tested by Ansaldo under the ZEUS project contract with Istituto Nazionale di Fisica Nucleare (INFN). It is a model of the ZEUS detector magnet. The coil has two layers and it is wound with a Rutheford cable stabilized with high purity aluminium (bare dimensions 15 × 4.3 mm) manufactured by EUROPA METALLI, Florence. The coil has an external aluminium cylinder with helium circulating in an aluminium pipe welded around it. The quench propagation velocity and the minimum quench energy have been measured during the tests. The quench back behaviour has been analyzed. In this paper we present the measurements and the results obtained from the data analysis.

A thin superconducting solenoid was designed (on the ground of a first conceptual study carried out by INFN [1]) and built [2] at ANSALDO ABB COMPONENTI. This detector was installed in the HERA ring accelerator (DESY, Hamburg) with its relative vacuum plant, 5.5 meters transfer line, current leads cryostat, current leads, power supply, dump resistor, breakers and computer control system. The magnet was cooled down and energizated to the nominal field of 1.8 T. In spite of the double layer winding configuration, and the indirect cooling system, no quench occurred. The results of the tests (finished on Febr.’90) and preliminary analysis are reported.

The construction progress status of the superconducting magnets for the ZEUS detector, commissioned by INFN Frascati and to be installed in the HERA e- p+ring (DESY, Hamburg), is reported. The first one is a double layer, two densities, aluminum stabilized coil 1849 mm in inner dia., 2487 mm in length and 32.6 mm thick, with a central field of 1.8 T and high particle transparency. The second one is a compensating magnet, wound by a copper stabilized Nb-Ti cable. Its coil has a central field of 5 T, inner dia. 370 mm, a length of 1200 mm and is inserted into a cold iron yoke. The main problems encountered during the large coil construction and the geometrical accuracy obtained are reported. Four splices among the high purity aluminum stabilized cable length were made. An outer support cylinder, 18 mm thick, was shrink fitted around the coil and then the temporary inner mandrel was removed. The distribution of mechanical stresses was measured in the different configurations. A large aluminum alloy vacuum chamber with high radiation transparency was built. The compensating coil is ready to be installed inside its stainless steel cryostat. The cryostat critical features are the high design pressure (20 bar) and the heavy cold mass.