M. Ohta
Keio University
8 Papers
42 Citations
M. Ohta is an academic researcher from Keio University. The author has contributed to research in topics: Ion source & Plasma. The author has an hindex of 7, co-authored 8 publications.
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Papers
Status and Operation of the Linac4 Ion Source Prototypes
J. Lettry,Davide Aguglia,P. Andersson,S. Bertolo,A. Butterworth,Y. Coutron,Alessandro Dallocchio,E. Chaudet,J. Gil-Flores,Roberto Guida,J. D. Hansen,Akiyoshi Hatayama,I. Koszar,E. Mahner,C. Mastrostefano,Serge Mathot,Stefano Mattei,O. Midttun,P. Moyret,D. Nisbet,K. Nishida,M. O’Neil,M. Ohta,M. Paoluzzi,C. Pasquino,H. Pereira,J. Rochez,J.-L. Sanchez Alvarez,J. Sanchez Arias,Richard Scrivens,T. Shibata,D. Steyaert,N. Thaus,Takashi Yamamoto +33 more
TL;DR: The volume source has produced a 45 keV H(-) beam of 16-22 mA which has successfully been used for the commissioning of the Low Energy Beam Transport (LEBT), Radio Frequency Quadrupole (RFQ) accelerator, and chopper of Linac4.
Plasma ignition and steady state simulations of the Linac4 H(-) ion source.
TL;DR: Plasma properties such as e(-)/ion densities and energies, sheath formation, and shielding effect are presented and provide insight to the plasma properties of the hydrogen plasma.
RF plasma modeling of the Linac4 H− ion source
S. Mattei,M. Ohta,Akiyoshi Hatayama,J. Lettry,Y. Kawamura,M. Yasumoto,Claus Schmitzer,Claus Schmitzer +7 more
- 11 Feb 2013
TL;DR: In this paper, a self-consistent model of the ICP RF-plasma in the Linac4 H− ion source currently being constructed at CERN was developed by a PIC-MCC method.
Numerical study of the inductive plasma coupling to ramp up the plasma density for the Linac4 H(-) ion source.
TL;DR: An Electromagnetic Particle in Cell model is employed, in which the collision processes have been calculated by a Monte Carlo method and the results have shown that the range of initial gas pressure from 2 to 3 Pa is suitable for ramping up plasma density via inductive coupling.
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Modeling of neutrals in the Linac4 H(-) ion source plasma: hydrogen atom production density profile and Hα intensity by collisional radiative model.
Takashi Yamamoto,T. Shibata,M. Ohta,M. Yasumoto,K. Nishida,Akiyoshi Hatayama,S. Mattei,Jacques Lettry,Keiji Sawada,Ursel Fantz +9 more
TL;DR: A collisional radiative model is constructed to calculate the effective production rate of H(0) atoms from H2 molecules in the model geometry of the radio-frequency (RF) H(-) ion source for Linac4 accelerator to validate the CR model by comparison with the experimental results from the optical emission spectroscopy.
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