MOPL012
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
JAEA/J-PARC, Tokai-mura, Japan
JAEA, Ibaraki-ken, Japan
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
| Paper | Title | Page |
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MOPL012 |
Residual Dose Measurement and Activation of the Injection Area in the J-PARC RCS | |
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| In the 3 GeV Rapid Cycling Synchrotron (RCS) of Japan Proton Accelerator Research Complex (J-PARC), we adopted multi-turn H charge exchange injection by using stripper foil in order to achieve high power proton beam. It is therefore impossible to neglect the interaction between stripper foil and the beam. As a result, there are high residual dose measured around the stripper foil. Based on detail numerical simulations by using PHITS code, it is identified that the secondary particles produced in the nuclear reactions due to foil beam interaction caused the high residual activity around foil. In this paper, we report a detail measurement of the residual dose around the stripper foil together with the cause estimated based on simulation studies. | ||
| TUPM5X01 | Injection Painting Improvements in the J-PARC RCS | 1 |
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| In the J-PARC 3GeV RCS, the injection painting is essential method for the reduction of the space charge force. In this method, the H− beam from Linac is arranged on the large phase space area of the ring orbit during multiple turns. To implement this method, painting magnets form the time variable beam orbit. Therefore, the precise output current control of the magnet power supply is required. Because the power supply controlled by mainly feedforward signal is operated, we developed the iterative tuning method for the optimum feedforward parameter determination. As a result, we could reduce the tracking error of the current compared to before. Furthermore, to improve the accuracy of the painting area size, we applied the output readjustment additionally. Because the current monitor value of the power supply was different from the actual magnetic field due to the delay in the circuit and the leakage field, we corrected the tracking of the current based on the measured painting area size determined by the analysis of the measured COD. As a result, we achieved the precise injection painting. This talk presents these improvement results of the injection painting in the RCS. | ||
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Slides TUPM5X01 [4.127 MB] | |
| THAM6X01 | The Path to 1 MW: Beam Loss Control in the J-PARC 3-GeV RCS | 1 |
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| The J-PARC 3-GeV RCS started 1-MW beam test from October 2014, and successfully achieved a 1-MW beam acceleration in January 2015. The most important issues in realizing such a high power routine beam operation are control and minimization of beam loss. This talk will present the recent progress of 1-MW beam tuning, especially focusing on our approaches to beam loss issues. | ||
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Slides THAM6X01 [1.854 MB] | |