LINAC2012 - List of Authors (Igarashi, Z.)

Paper	Title	Page
TUPB102	Design and Performances of Phase Monitor in J-PARC Linac	699
	A. Miura JAEA/J-PARC, Tokai-mura, Japan Z. Igarashi, T. Miyao KEK, Ibaraki, Japan
	J-PARC linac employs a fast current transformer (FCT) as a beam phase monitor to calculate the beam energy by time-of-flight method. We have installed and used 61 FCTs in the current beam line. Because the phase measurements at additional 41 points in the future ACS sections are required for the energy upgrade project with adding 21 ACS (Annular Coupled Structure) cavities, we stared the design and fabrication of FCTs as the phase measurement devices. In addition, J-PARC linac employs the 4-stripline beam position monitors (BPMs) for the beam position measurement. It has been considered that the signals from striplines of BPM would be useful for a phase measurement. A phase measurement using a BPM has been successfully conducted. In order to evaluate the performances of the FCT, the signal sensitivity and cut-off frequency of newly fabricated FCT are measured. Also, these data of the BPM are also measured to be compared with the data of FCT. Based on the results of the comparing both measurements, the superiority of both monitors for beam phase measurement is discussed.

Paper

Title

Page

Design and Performances of Phase Monitor in J-PARC Linac

699

A. Miura
JAEA/J-PARC, Tokai-mura, Japan
Z. Igarashi, T. Miyao
KEK, Ibaraki, Japan

J-PARC linac employs a fast current transformer (FCT) as a beam phase monitor to calculate the beam energy by time-of-flight method. We have installed and used 61 FCTs in the current beam line. Because the phase measurements at additional 41 points in the future ACS sections are required for the energy upgrade project with adding 21 ACS (Annular Coupled Structure) cavities, we stared the design and fabrication of FCTs as the phase measurement devices. In addition, J-PARC linac employs the 4-stripline beam position monitors (BPMs) for the beam position measurement. It has been considered that the signals from striplines of BPM would be useful for a phase measurement. A phase measurement using a BPM has been successfully conducted. In order to evaluate the performances of the FCT, the signal sensitivity and cut-off frequency of newly fabricated FCT are measured. Also, these data of the BPM are also measured to be compared with the data of FCT. Based on the results of the comparing both measurements, the superiority of both monitors for beam phase measurement is discussed.