| Paper | Title | Page |
|---|---|---|
| MOPWA005 | Development of a Feedback Control System for Resonant Power Supplies in the J-PARC 3-GeV Synchrotron | 672 |
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| In the J-PARC 3-GeV Synchrotron, dipole magnets and seven families of quadrupole magnets are excited with a DC-biased 25 Hz sinusoidal waveforms using an individual resonant circuits. This paper proposed a feedback system to improve the amplitude and phase stability, specially against variation of capacitance caused by temperature characteristics in the resonant circuits. The control system has been successfully demonstrated and achieved amplitude and phase stability under ±0.005% and ±0.5 uS, respectively. | ||
| MOPWA008 | Power Supply of the Pulse Steering Magnet for Changing the Painting Area between the MLF and the MR at J-PARC 3 GeV RCS | 681 |
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| The power supply of the pulse steering magnet (PSTR) has been produced. The PSTR of the 3-GeV RCS (Rapid Cycling Synchrotron) in the J-PARC (Japan Proton Accelerator Research Complex) aims at changing the painting area in a pulse-to-pulse mode at 25Hz between the MLF (Material and Life science Experimental Facility) and the MR (50-GeV Main Ring synchrotron) at J-PARC. The power supply has the equipment used to excite the pulse current and the direct current (DC) to correspond to two modes that the paint injection for beam users and the central injection for beam commissioning. In case of the paint injection, the power supply excites the current from 40 A to 450 A in pulse mode, which has the capability to switch from positive to negative polarity. The pulse current has been performed with good accuracy whose deviation to a setting current becomes to be less than ± 0.2 %. In case of the central injection, the power supply excites the current from 1000 A to 3000A in DC mode, which has been realized output current deviation below ± 0.01 %. This paper summarizes the design parameters and the experimental results of the power supply. | ||
| THPFI016 | DESIGN CONSIDERATION OF BEAM DUCTS FOR QUADRUPOLE CORRECTORS IN J-PARC RCS | 3327 |
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which rapidly correct the tunes, are planned to be installed during the summer shutdown in 2013. The characteristic of the excitation pattern of such quadrupoles (quadrupole corrector) is their fast change of magnetic field, which are more than 200T/s at the fastest point. In this report, we describe a deliberation flow about the design of a vacuum chamber, which is installed in the quadrupole corrector. The effect of eddy current was calculated in the case of the current titanium vacuum chamber. The results showed that the temperature rise was too much (up to ~350oC) and the magnetic field in the vacuum chamber is largely distorted by the eddy current. Therefore we decided to employ an alumina ceramics vacuum chamber, for which we have a past achievement in RCS*. We estimated the displacement and stress, which is caused by the atmospheric pressure, for the alumina ceramics vacuum chamber and vacuum component around it by making the calculation model for the finite element method. It was found that there was no large displacement and stress by installing the alumina ceramics vacuum chamber.
*M. Kinsho, et al. Vacuum 81 (2007) 808. |
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| THPWO032 | Progress of Injection Energy Upgrade Project for J-PARC RCS | 3833 |
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| The injection energy of the J-PARC RCS will be upgraded in 2013. New power supplies for the shift bump magnet system will be installed. Some of other systems, upgrade of the painting bump power supplies and pulse steering systems, are already installed and tested or used for the nominal operation. The paper reports the progress of injection energy upgrade project. | ||