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Title |
Page |
| MPPT006 |
The Extraction Kicker System of the RCS in J-PARC
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1009 |
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- J. Kamiya, T. Takayanagi
JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
- T. Kawakubo, S. Murasugi, E. Nakamura
KEK, Ibaraki
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The kicker magnet plays a role of extracting the proton beam which is accelerated up to 3GeV by the Rapid Cycling Synchrotron in J-PARC. The kicker system is required the fast rise time of the magnetic field because the interval between the beam bunches is only 349nsec. The kicker magnet is the distributed type. The findings in our measurements revealed that the delay time in the magnet is about 180nsec. The power supply has the pulse forming network system, which consists of co-axial cables whose characteristic impedance is 10 ohm. We accomplished the current rise time of 80 nsec quickness. Therefore we had a good prospect of the fast rise time of the magnetic field. The characteristic impedance of the kicker magnet was also measured. The value was close to 10 ohm. There will be no large mismatching between the power supply and the magnet. This pulse magnet is installed in the vacuum chamber to prevent the electric discharge. Outgas from the components has the adverse effects the vacuum in the accelerator. We have reduced the outgas rate from the ferrite core and aluminum plates which construct the magnet by backing them at appropriate temperature.
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| MPPT007 |
Design of the Pulse Bending Magnets for the Injection System of the 3-GeV RCS in J-PARC
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1048 |
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- T. Takayanagi, Y. Irie, J. Kamiya
JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
- T. Kawakubo, I. Sakai
KEK, Ibaraki
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The pulse bending magnets for the injection system of the 3-GeV RCS in J-PARC has been designed using a 3D magnetic analysis code. The injection system consists of the pulse bending magnets for the injection bump orbit, which are four horizontal bending magnets (shift bump), four horizontal painting magnets (h-paint bump), and two vertical painting magnets (v-paint bump). The injection beam energy and the extraction beam power are 400 MeV and 1 MW at 25-Hz repetition rate, respectively. The beam orbit area with a full acceptance beam of the injection beam, painting beam and the circulating beam at the shift bump points is a 400 mm width and a 250 mm height.The shift bump has accomplished 1.0% good field region at 0.22 T.
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| FPAE067 |
Present Design and Calculation for the Injection-Dump Line of the RCS at J-PARC
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3739 |
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- P.K. Saha, N. Hayashi, H. Hotchi, Y. Irie, F. Noda, T. Takayanagi
JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
- S. Machida, I. Sakai
KEK, Ibaraki
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The RCS(rapid cycling synchrotron) of J-PARC(Japan proton accelerator research complex) acts as an injector to the main ring as well as a high-power beam for the spallation neutron source at a repetition rate of 25 Hz, where at present the injection and the extraction beam energy are chosen to be 0.181 GeV and 3.0 GeV, respectively. The present work concerns on the present design and calculations for the injection-dump line of the RCS, which includes, 1) an accurate aperture list of all elements taking into account a wide range of the betatron tune, effect of changing injection modes, multiple trajectories of different particles after the charge-exchange foil( like H0 from the H- and H- beam itself)and 2) an accurate estimation of the uncontrolled beam losses especially from the H0-excited states, multiple coulomb scattering at the charge-exchange foil and also the lorentz stripping loss at the septum magnets so as to optimize them concerning mainly the radiation issues as well as for the hands-on maintenance.
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