Electromagnetic transient simulation using a shell approach for ITER CXRS upper port plug due to plasma vertical displacement events

Transient electromagnetic (EM) analysis is presented focusing on main components of the ITER core charge exchange recombination spectroscopy (cCXRS) port plug developed by Forschungszentrum Julich (F2J), ITER-NL and UKAEA(CCFE) in 2009. The cCXRS primary function is to transfer the light in the visible part of spectra emitted by interaction of the plasma ions with a diagnostic neutral beam.The TYPHOON software package has been used for the EM analysis. The code is dedicated for simulation of transient electromagnetic processes using a shell approach in the integral-differential formulation to represent conducting structures with a set of multi-connected shells arbitrary located in a space. The advantage of the shell approach is a higher flexibility in modelling detailed structures as compared with widely used 3D models. On the other hand, the shell approach requires ultimate care in modelling relatively thick structures. These issues are discussed in the paper.Two vertical displacement events (VDE) which seem to result in the largest EM loads on the main cCXRS components have been agreed with FZJ and simulated. Transient electromagnetic processes caused by different sources have been considered separately, and then superimposed to obtain the total solution. Three types of transient processes for each type of VDE have been analyzed: (1) due to variations of a toroidal plasma current, shape and position and due to variations of poloidal field coils (PFC) and central solenoid (CS) currents, (2) due to variations of the Halo current and (3) due to variations of a toroidal magnetic flux of plasma. The analysis covers two options for electrical contact between the main shell (MS) of the port plug and the blanket shield module (BSM).The results are supposed to be used for benchmarking with independent 3D EM models developed for the upper port plug. (C) 2011 Elsevier B.V. All rights reserved

A method of the magnetic field formation in cyclotron DC-72

A method of the magnetic field formation in the cyclotron DC-72 model (scale 1:5) is described. The cyclotron is planned to be built in Slovakia. The stages in the shimming of the cyclotron sectors and an automatic system designed for magnetic measurements are described. The data on the magnetic field measurements in the median plane of the cyclotron are presented. A brief description of a computer simulation model and an algorithm of fitting the required sector profiles is presented, as well as the data on the computer simulation of magnetic field distributions. The data on the magnetic field measurements and those on the computer simulations are compared and analyzed. Possible reasons of differences between the measured and simulated data are discussed. The results of the above mentioned computer simulations will be used for building a large facility - the cyclotron DC-72

Control strategy for mitigation of pulsed heat load transferred to ITER cryoplant from magnets

Active mitigation of pulsed heat load is foreseen for the ITER superconducting magnets during cyclic plasma scenarios to ensure stable operation of the cryoplant. The paper addresses a promising feedback control to smooth heat pulses in the primary cryogenic circuits of the ITER magnets. A feedback control signal is proposed that can be derived from direct measurements of helium parameters in a low pressure return cryoline to the cryoplant. Configurations with two or more LHe baths were investigated at the Auxiliary Cold Box (ACB) level. Efficiency of the proposed control approach was evaluated in thermohydraulic simulations. A possibility to control several cryogenic loops using a common regulator is demonstrated

Reconstruction of the 3-dimensional magnetic fields of the strong focusing separator

For unambiguous identification of products of nuclear reactions by the (TOF-?E) method, it is necessary to know exactly the magnetic field distributions, the 3D field map for the entire working area of separator. The possibility of the field reconstruction inside the total volume surrounded by the closed surface, on which the magnetic measurements are performed, is demonstrated in this paper. Distributions of the measured magnetic field components of the magnets, forming the magnetic structure of the separator, as well as the respective reconstructed fields together with the estimated reconstruction errors, are presented. Precise simulation of particle trajectories inside the separator becomes possible as a result of this wor