Magnetic characteristics, reactors

Any increase in the fundamental value of the current beyond I or a voltage drop across the coil of more than 150% of the reactor voltage (this may occur in the presence of harmonics) may, however, saturate the core and reduce the reactance of the coil. Magnetically shielded reactors therefore have limitations when the system harmonics are high or when linear V-/ characteristics are desirable beyond 150% of the rated fundamental current. 

These are meant to provide high impedance to harmonic currents and block their entry or reduce their amplitudes and are therefore also known as blocking reactors. They may have any of the magnetic characteristics shown in Figure 27.2 and have a fixed reactance, rated continuously. 

For the theory of neutralization of the magnetic effect on the conductor in a non-magnetic shielding, refer to the continuous enclosures for isolated phase bus systems discussed in Section 31.2.2. As a result of non-magnetic shielding there will be no saturation of the iron core and the V-I characteristic of the reactor will remain almost linear. 

Figure 27.11 Typical characteristics of a current limiting reactor (coreless, gapped iron core or magnetically shielded core type)...

Introduction Selection of power reactors Magnetic charecteristics Design criterion and / (p characteristics of different types of reactor Application... 

Neutronic calculations show that fast neutron fluxes at fusion reactor magnet locations are rather high and the energy deposited by neutrons compares to or exceeds that by y-rays [2]. It is therefore important to establish the characteristics of radiation damage due to fast neutrons in comparison with those due to y-rays. 

The electrical properties of insulators for superconducting magnets are of crucial importance in relation to the operational reliability of fusion reactors [81], In the present section, the characteristics in original electrical properties of polymers at cryogenic temperatures are briefly introduced and then the effects of radiation on these properties are surveyed. 

The characteristic circular-shape of the tokamak reactor is clearly seen here. The reactor uses strong magnetic fields to contain the intensely hot fusion reaction and keep it from direct contact with the interior reactor walls. 

A capacitively coupled reactor designed to permit continuous coating of a moving substrate with plasma polymer has been described [ 1 ]. In this paper the results of a study of the plasma polymerization of tetrafluoroethylene in such a reactor presented. Plasma polymer has been deposited on aluminum electrodes as well as on an aluminum foil substrate placed midway between electrodes. The study particularly explores conditions in which deposition is minimized on the electrode. For this reason the chemical nature of the polymer formed in a low flow rate (F = 2 cm (S.T.P.)/min) and low pressure (p = 60 mlllltorr) plasma has been analyzed by the use of ESCA (electron spectroscopy for chemical analysis) and deposition rate determinations. This method combined with the unusual characteristics of TFE plasma polymerization (described below) has yielded Information concerning the distribution of power in the inter-electrode gap. The effects of frequency (13.56 MHz, 10 KHz and 60 Hz), power and magnetic field have been elucidated. The properties of the TFE plasma polymer prepared in this apparatus are compared to those of the plasma polymer deposited in an inductively coupled apparatus [2,3]. 

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