| Paper |
Title |
Page |
| TUPD016 |
Grounding and Induced Voltage Issues of the Injection Bump Magnet System of the 3-GeV RCS in J-PARC
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1461 |
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- T. Takayanagi, J. Kamiya, M. Kinsho, T. Ueno, M. Watanabe, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
- Y. Irie
KEK, Ibaraki
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The power supply of the injection shift bump magnets is required to rate a large current with high precision. The rating current is 20 kA and the pulse width is 1.3 ms. The power supply with the multiple connected two-quadrant IGBT choppers, which is controlled by the switching frequency over 48 kHz, realizes the tracking error less than 1.0 %. However, the switching noise due to the IGBT choppers caused damages to the control device and the measuring instrument. The ground cables were changed to copper sheets, so that the voltage due to the switching noise between the power supply board and the ground decreased from 800 V to 40 V. Furthermore, the output voltage of the RF shield was measured in connection with the several waveform patterns. These results showed the good agreement with the calculation and the experiment. The good performances of the shift bump magnet and power supply have been confirmed.
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| THXG02 |
J-PARC Progress and Challenges of Proton Synchrotrons
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2897 |
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- M. Kinsho
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
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After briefly outlining the status of the J-PARC linac, the talk should concentrate on describing the outcome of the 3 GeV J-PARC synchrotron commissioning programme, and also include discussion of the challenges of successfully running high power proton synchrotrons.
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Slides
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| THPP084 |
Discussion on RCS versus AR on the Basis of J-PARC Beam Commissioning for Pulsed Spallation Neutron Source
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3557 |
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- Y. Yamazaki
KEK/JAEA, Ibaraki-Ken
- M. Kinsho
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
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Over a decade it is one of the most controversial issues regarding the accelerator scheme choice whether RCS or AR should be chosen for the pulsed spallation neutron source. In order to simplify the discussion, we compare 3-GeV RCS with 1-GeV AR. The former is J-PARC scheme while the latter is SNS scheme. To summarize the discussion, RCS technology is much more difficult than AR technology, although RCS has many advantages over AR arising from its low beam current for the same beam power. Now, the J-PARC 3-GeV RCS was actually commissioned. On the basis of its experience, the discussion will be resumed.
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| THPP097 |
Commissioning Results of the Kicker Magnet in J-PARC RCS
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3590 |
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- J. Kamiya, M. Kinsho, M. Kuramochi, T. Takayanagi, T. Togashi, T. Ueno, M. Watanabe, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
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Installation of the kickers in the extraction section of the RCS in J-PARC facility was completed. And they succeeded to extract the 3GeV proton beams in the first beam test. The operation parameters of the kickers agreed well with the parameters which were estimated from the magnetic field measurement and the current test of the power supplys. In this report, we summarized the results of the excitation test and the commissioning of the kicker magnet. The results of the magnetic field measurement showed the good uniformity in the wide range of the aperture. The characteristic feature of each kicker power supply was also measured precisely. Although the rise time and jitter of the output pulse have some minor variation due to the different characteristics of the thyratrons, the degree of variation was acceptably small. Combining the results of the magnetic field measurements, the relation between the charging voltage and the magnetic field was obtained for each kicker. The accelerated beam was successfully extracted at the operation parameters which were obtained from the relationship. The measurements result which was obtained by using the beam is also reported.
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| THPP112 |
Leakage Field of Septum Magnets of 3 GeV RCS at J-PARC
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3626 |
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- M. Yoshimoto, H. Hotchi, J. Kamiya, M. Kinsho, M. Kuramochi, P. K. Saha, T. Takayanagi, T. Togashi, T. Ueno, M. Watanabe
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
- H. Harada
Hiroshima University, Graduate School of Science, Higashi-Hiroshima
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Septum magnets are installed in RCS (Rapid cycling Synchrotron) at J-PARC for the beam injection and extraction. In order to realize MW beam in the RCS ring and reduce the beam loss during the beam injection and extraction, the septum magnets have large physical aperture and are operated in DC. Thus there are high magnetic fields in the gaps during the acceleration, but the leakage fields are nevertheless suppressed down to a few Gauss to suppress the closed orbit distortion. In order to reduce the magnetic leakage field from the septa at beam orbit in the RCS ring, the silicon steel sheets are set for magnetic shield. In addition a few ring vacuum chambers are made by the magnetic stainless steel. Up to now, the development and field measurement of the septum magnets has been finished, and the beam commissioning of the RCS are carried out. In this presentation, the field measurements of the septum magnets are summarized and the influences of the leakage field upon the beam orbit are reported.
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| THPP134 |
Injection and Extraction DC Magnets Power Supplies for 3GeV Rapid Cycling Synchrotron of J-PARC
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3676 |
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- M. Watanabe, J. Kamiya, M. Kinsho, T. Takayanagi, Y. Yamazaki, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
- K. Hirano
JAEA/LINAC, Ibaraki-ken
- Y. Irie
KEK, Ibaraki
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Proton beams have been successfully accelerated to the design energy of 3 GeV in the RCS at the J-PARC*. In the injection, dump and extraction sections of the RCS, septum magnets, a quadrupole magnet, dc kicker magnets and steering magnets have been installed and operated at DC. For the septum magnets, there is little space area available for the septum coil and a magnetic shield**. Therefore the power supplies are required high excitation current. Maximum currents of the injection and dump septum magnets are less than 7 kA. The extraction septum magnets need the maximum current of 12 kA***. For saving the cost and the installation space of the extraction septum magnets power supplies, a main power supply, which excites three extraction septum magnets in series, and three auxiliary power supplies for adjusting the current to the each magnet are employed. Long-term stability and the current ripples are required to be less than the order of 100 ppm for those power supplies in order to provide the required acceptance for the beams. This presentation shows design and measurements of the the injection and extraction DC power supplies.
*JAERI Technical Report 2003-044 and KEK Report 2002-13.
**M. Yoshimoto et al. Proc. of EPAC'06.
***M. Watanabe et al. IEEE Transactions on applied superconductivity, Vol.16, No.2, 2006.
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