LINAC2018 - List of Authors (Ohkoshi, K.)

Paper	Title	Page
TUPO079	Numerical and Experimental Study of H⁻ Beam Dynamics in J-PARC LEBT	519
TUOP10	use link to see paper's listing under its alternate paper code
	T. Shibata, K. Ikegami, Y. Liu, K. Ohkoshi, M. Otani J-PARC, KEK & JAEA, Ibaraki-ken, Japan A. Miura, H. Oguri, K. Shinto JAEA/J-PARC, Tokai-mura, Japan F. Naito, K. Nanmo, A. Takagi KEK, Tokai, Ibaraki, Japan
	Negative hydrogen ion (H⁻) beam dynamics in J-PARC Low Energy Beam Transport (LEBT) has been investigated by numerical modeling which calculates particle transport with effect of space charge and collision processes. Understandings of H⁻ beam transport in LEBT is important for high transmission rate from Ion Source (IS) to Radio Frequency Quadrupole (RFQ) in J-PARC in higher beam current in future. In 2017, 45 mA beam current of H⁻ has been extracted from IS in J-PARC user operation which has been increased from 30 mA in last 2 years. The beam current is planned to be increased to 50 mA in the next upgrade. As the beam current increase, IS/LEBT commissioning becomes more difficult because of the higher space charge (SC). Especially in J-PARC, vacuum pressure is around 10^-5 Pa by 15 mmf orifice located in the center of LEBT. The orifice prevents residual gas injection from IS to LEBT/RFQ and thus produces stronger SC effect. In the presentation, numerical results are compared with actual results from J-PARC Linac beam commissioning. A comparison of the results shows that location of the 15 mmf orifice results in two peaks of RFQ transmission rate against SOL currents.
	Slides TUPO079 [0.968 MB]
	Poster TUPO079 [1.699 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO079
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

TUPO079

Numerical and Experimental Study of H⁻ Beam Dynamics in J-PARC LEBT

519

TUOP10

use link to see paper's listing under its alternate paper code

T. Shibata, K. Ikegami, Y. Liu, K. Ohkoshi, M. Otani
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
A. Miura, H. Oguri, K. Shinto
JAEA/J-PARC, Tokai-mura, Japan
F. Naito, K. Nanmo, A. Takagi
KEK, Tokai, Ibaraki, Japan

Negative hydrogen ion (H⁻) beam dynamics in J-PARC Low Energy Beam Transport (LEBT) has been investigated by numerical modeling which calculates particle transport with effect of space charge and collision processes. Understandings of H⁻ beam transport in LEBT is important for high transmission rate from Ion Source (IS) to Radio Frequency Quadrupole (RFQ) in J-PARC in higher beam current in future. In 2017, 45 mA beam current of H⁻ has been extracted from IS in J-PARC user operation which has been increased from 30 mA in last 2 years. The beam current is planned to be increased to 50 mA in the next upgrade. As the beam current increase, IS/LEBT commissioning becomes more difficult because of the higher space charge (SC). Especially in J-PARC, vacuum pressure is around 10^-5 Pa by 15 mmf orifice located in the center of LEBT. The orifice prevents residual gas injection from IS to LEBT/RFQ and thus produces stronger SC effect. In the presentation, numerical results are compared with actual results from J-PARC Linac beam commissioning. A comparison of the results shows that location of the 15 mmf orifice results in two peaks of RFQ transmission rate against SOL currents.

Slides TUPO079 [0.968 MB]

Poster TUPO079 [1.699 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO079

About •

paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)