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Oguri, Hidetomo
no journal, ,
no abstracts in English
Ueno, Akira
no journal, ,
In order to achieve the design beam power of 1 MW, a negative hydrogen ion source with a peak beam current of 60 mA within horizontal and vertical 1.5 
mm
mrad emittances is under development. The beam extraction system is the same with the J-PARC ion source, which is using a lanthanum hexaboride (LaB
) filament. The inner diameter of the plasma chamber is enlarged form 100 mm to 120 mm in order to install a water cooled plate attached to the plasma electrode (PE) and a cesium (Cs) injector. The end flange is modified to install the RF-antenna. A rod-filter flange is installed to produce a low-temperature plasma around the PE. For the conditions of the pulsed RF duty of 2.5% (1 ms 
25 Hz), the air cooled PE (PE temperature of 120 
C) and opening the Cs valve for 4 min/day, a negative hydrogen ion beam with a peak beam current of more than 60 mA within 1.5 mmmrad emittances is successfully produced for more than 100 hours.
Yamazaki, Saishun
no journal, ,
A cesium (Cs) seeded RF-driven H
ion source using an internal-antenna is under development for the Japan Proton Accelerator Research Complex (J-PARC). The J-PARC second stage requirements are an H ion beam of 60 mA within normalized emittances of 1.5 
mmmrad both horizontally and vertically, and a flat top beam duty factor of 1.25% (500 
s 25 Hz). An H ion beam current of 77.5 mA with a flat top duty factor of 2% (800 s 25 Hz), whose approximately 90% (corresponding to approximately 70 mA) of each emittance is within 1.5 mmmrad, is successfully extracted from it. The experimental results of axial magnetic field (AMF) optimization with an axial magnetic field correction (AMFC) coil, which significantly enhances the H ion beam current by 10% typically, are presented in this meeting.