TY  - CONF
AU  - Sato, K.
AU  - Hamada, E.
AU  - Hashimoto, Y.
AU  - Igarashi, S.
AU  - Koseki, T.
AU  - Sato, Y.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Multi-Ribbon Profile Monitor for High Power Proton Beam at J-PARC MR Abort Line
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Japan Proton Accelerator Research Complex (J-PARC) Main Ring (MR), the world-class high intensity proton synchrotron, provides proton beam to two experimental facilities with two extraction modes: Fast extraction (FX) and Slow extraction (SX). The number of protons per pulse (ppp) in MR recorded the world highest value of 2.6×10¹⁴ in the FX mode. Now we are planning to increase the ppp further up to 3.3×10¹⁴ in near future. The beam profile is one of the most important parameters to discuss the high intensity beam dynamics in MR. Monitors using multi-wires / ribbons are effective to measure the beam profile with good accuracy and wide dynamic range. However, they cause significant beam losses by interactions with high-intensity circulating beam in synchrotrons. Recently, we installed new multi-ribbon profile monitor (MRPM) in an abort line in MR. The abort line is one of the extracted beam lines of the FX system. It has a quadrupole doublet which is called Abort Q and transports extracted beam to a beam dump. The FX system can extract the circulating beam in MR with an arbitrary energy. Performing the single-pass measurement with MRPM and changing the transfer matrix by sweeping field strength of Abort Q, the emittance of the extracted beam can be measured. In this paper, we present the design, manufacturing, and results of the first beam test of newly installed MRPM system.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2561
EP  - 2563
KW  - target
KW  - proton
KW  - extraction
KW  - emittance
KW  - electron
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPGW039
UR  - http://jacow.org/ipac2019/papers/wepgw039.pdf
ER  - 

TY  - CONF
AU  - Yasui, T.Y.
AU  - Igarashi, S.
AU  - Koseki, T.
AU  - Ohmi, K.
AU  - Sato, Y.
AU  - Satou, K.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Tune Shifts and Optics Modulations in the High Intensity Operation at J-PARC MR
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - J-PARC Main Ring (MR) is the intensity-frontier proton accelerator. The beam intensity of 2.6×10¹⁴ protons per pulse has been achieved for the current user operation. In this high-intensity operation, the tune spread caused by the space-charge is one of the main reasons for beam loss. The modulation of the betatron function and the tune shift were simulated with a PIC algorithm calculation code*. The simulation results showed that the space-charge effects were dominant in small particle action, and the sextupole fields effects were dominant in large particle action. Because sextupole strength is large in MR, sextupole fields induce substantial tune shifts. At the benchmark of the space-charge simulation, the simulation results matched the analytical space-charge calculations performed without sextupoles. It was found that the betatron function was modulated at most 6% by the space-charge effects and at most 8% by the effects of sextupoles in J-PARC MR. These effects to the injection beam optics matching and to the beam aperture will be investigated.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3148
EP  - 3151
KW  - space-charge
KW  - simulation
KW  - betatron
KW  - sextupole
KW  - quadrupole
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPTS024
UR  - http://jacow.org/ipac2019/papers/wepts024.pdf
ER  -