US 7,544,952 B2
Multivalent ion generating source and charged particle beam apparatus using such ion generating source
Makoto Sakurai, Kobe (Japan); Fumiharu Nakajima, Kobe (Japan); Takunori Fukumoto, Kobe (Japan); Nobuyuki Nakamura, Chofu (Japan); Shunsuke Ohtani, Naka-gun (Japan); and Shinro Mashiko, Kobe (Japan)
Assigned to Japan Science and Technology Agency, (Japan)
Appl. No. 11/576,945
PCT Filed Apr. 08, 2005, PCT No. PCT/JP2005/007284
§ 371(c)(1), (2), (4) Date Apr. 09, 2007,
PCT Pub. No. WO2006/040850, PCT Pub. Date Apr. 20, 2006.
Claims priority of application No. 2004-296890 (JP), filed on Oct. 08, 2004.
Prior Publication US 2008/0087842 A1, Apr. 17, 2008
Int. Cl. H01J 27/20 (2006.01)
U.S. Cl. 250—427  [250/423 R; 250/424; 313/153; 313/160; 315/85] 9 Claims
OG exemplary drawing
 
1. A source of generating multicharged ions, including:
an ion source electrode comprising an electron source, a drift tube that constitutes an ion trapping region and a collector;
a superconducting magnet for ion entrapment; and
an ion infeed means,characterized in that it further includes:
a first vacuum chamber receiving said ion source electrode;
a second vacuum chamber receiving said superconducting magnet;
wherein said first vacuum chamber is disposed by being passed through said second vacuum chamber,
a vacuum pumping means are provided to said first and said second vacuum chambers, respectively,
a first magnetic shield is provided in a peripheral area of the second vacuum chamber on the first vacuum chamber side so that the magnetic field by said superconducting magnet does not leak to the electron source of said ion source electrode and said drift tube of the collector side,
at least the opposing surfaces of said first and second vacuum chambers are formed with a nonmagnetic material so that the magnetic field by said superconducting magnet is applied to said drift tube, and
the electron source of the ion source electrode in said first vacuum chamber is received in a second magnetic shield part.