K. Hara

Power-cycling degradation monitoring of an IGBT module with VCE(sat) measurement in continuous operation of a chopper circuit

Kazunori Hasegawa, K. Hara, Nobuyuki SHISHIDO, Satoshi Nakano et autres

This paper presents a power-cycling degradation monitoring method of an IGBT module with a VCE(sat) sensing circuit and junction temperature prediction by a three-dimensional structure model. A chopper circuit was introduced to provide a continuous-current-conducting operation of the IGBT module. The VCE(sat) …

jp (code pays fourni par la source)

Improvement of the longitudinal phase space tomography at the J-PARC synchrotrons

Hidefumi Okita, Fumihiko Tamura, Masanobu Yamamoto, Masaharu Nomura et autres

Abstract The longitudinal phase space tomography, which reconstructs the phase space distribution from the one-dimensional bunch profiles, is used in various accelerators to measure longitudinal beam parameters. At the J-PARC, an implementation of the phase space tomography based on the Convolution Back …

jp, ch, gb (code pays fourni par la source)

Search for the baryon number and lepton number violating decays $\tau^-\to \Lambda\pi^-$ and $\tau^-\to \bar{\Lambda}\pi^-$ at Belle II

I. Adachi, L. Aggarwal, H. Ahmed, H. Aihara et autres

We present a search for the baryon number $B$ and lepton number $L$ violating decays $τ^- \rightarrow Λπ^-$ and $τ^- \rightarrow \barΛ π^-$ produced from the $e^+e^-\to τ^+τ^-$ process, using a 364 fb$^{-1}$ data sample collected by the Belle~II experiment at the …

Design studies on a high-power wide-band RF combiner for consolidation of the driver amplifier of the J-PARC RCS

Hidefumi Okita, F Tamura, MITSUGU YAMAMOTO, M. Nomura et autres

Abstract A power upgrade of the existing 8-kW solid-state driver amplifier is required for the acceleration of high intensity proton beams on the J-PARC 3-GeV Rapid Cycling Synchrotron. The development of a 25-kW amplifier with gallium nitride (GaN) HEMTs, based on 6.4-kW …

jp, ch (code pays fourni par la source)

Conceptual design of a single-ended MA cavity for J-PARC RCS upgrade

Masanobu Yamamoto, Masaharu Nomura, Taihei Shimada, Fumihiko Tamura et autres

The Japan Proton Accelerator Research Complex (J-PARC) Rapid Cycling Synchrotron (RCS) employs Magnetic Alloy (MA) loaded cavities. The rf power is fed by vacuum tubes in push-pull operation. We realize the multi-harmonic rf driving and the beam loading compensation thanks to the …

jp (code pays fourni par la source)

Measurement of thermal deformation of magnetic alloy cores of radio frequency cavities in 3-GeV rapid-cycling synchrotron of Japan proton accelerator research complex

Taihei Shimada, M. Nomura, Fumihiko Tamura, Masanobu Yamamoto et autres

jp (code pays fourni par la source)

The feasibility study of ghost hits reduction in Belle2/SVD using P-N charge correlation from beam test data

K. Kong Wan, Hiroki Aihara, A. Ishikawa, Yoshinori Onuki et autres

Vacuum tube operation analysis under multi-harmonic driving and heavy beam loading effect in J-PARC RCS

Masanobu Yamamoto, M. Nomura, Taihei Shimada, Fumihiko Tamura et autres

jp, de (code pays fourni par la source)

Study of χ_{bJ}(1P) Properties in the Radiative Υ(2S) Decays

Ichiro Adachi, K. Adamczyk, H. Aihara, S. Al Said et autres

Mechanisms of increasing of the magnetic alloy core shunt impedance by applying a transverse magnetic field during annealing

M. Nomura, Taihei Shimada, Fumihiko Tamura, Masanobu Yamamoto et autres

jp (code pays fourni par la source)

Ribbon thickness dependence of the Magnetic Alloy core characteristics in the accelerating frequency region of the J-PARC synchrotrons

Masahiro Nomura, Taihei Shimada, Fumihiko Tamura, Masanobu Yamamoto et autres

jp, de (code pays fourni par la source)

INFLUENCE OF CORE WINDING TENSION AND RIBBON QUALITY ON THE MA CORE RF CHARACTERISTICS

M. Nomura, A. Schnase, T. Shimada, Fumihiko Tamura et autres

During the development of Magnetic Alloy (MA) cores for RF cavities in J-PARC synchrotrons, we found that the core shunt impedance was increased by lowering the core winding tension to improve the electrical insulation between MA ribbon layers. The lower winding tension …