Conceptual design of a bipolar kicker magnet for the J-PARC-Kamioka Neutrino Project
The Japanese Hadron Facility (J-PARC) includes a ring in which the beam is accelerated from an energy of 3 GeV to 50 GeV. One of the proposed experiments, which require the beam to be extracted from this ring, is a long baseline neutrino oscillation experiment. Space constraints in the lattice of the ring result in a requirement for a novel bipolar combined function kicker that can be used for fast extraction or abort. Magnetic field pulses with a rise time of approximately 1.1/spl mu/s and 4.3/spl mu/s flat top duration are required. One of the stringent design requirements of the extraction system is a flat top ripple of less than /spl plusmn/1%. The proposed kicker system is composed of 6 kicker magnets of 1.5 m length each, powered by pulse forming lines (PFL's). To achieve the required kick angle of /spl plusmn/5.32 mrad a low characteristic impedance has been chosen. This paper discusses several different concepts for the kicker system and presents the results of investigations into options for system impedance, and kicker magnet type including transmission line, lumped inductance and hybrid-transmission line.
Hardware for Beam Injection and Extraction
The injection and extraction beam‐lines of the 50 GeV synchrotron in the JHF project are described. The 50 GeV ring is equipped with one injection line from the preceding 3 GeV ring and three extraction lines for experimental facilities and for beam aborts. Some of the characteristic features on the injection/extraction hardware components, particularly on the kickers, are mentioned. These features are intended to fulfill two important demands on the kicker design, namely, a reduction of reflected waveforms and a bipolar fast extraction by the fast reverse of the kick direction.
Finite Difference Modeling on the Temperature Field of Substrate in Friction Surfacing
Friction surfacing is an advanced process of great potential, especially in the field of repair and reclamation of worn and damaged components. As a kind of thermal processing technology, the temperature profile and changes of the substrate in friction surfacing are important factors to get coatings of high quality. In this paper, the temperature field of the substrate during the process is simulated by finite difference method. The results are consistent with experiments, reappearing the temperature change of the substrate during friction surfacing, allowing further study on figuration and quality of coatings.