ECRIS2012 - List of Authors (Takayama, K.)

Paper

Title

Page

The Einzel Lens Longitudinal Chopper

95

K. Takayama, T. Adachi
KEK, Ibaraki, Japan
T. Adachi, K.W. Leo
Sokendai, Ibaraki, Japan

The Einzel lens longitudinal chopper [1] placed just after the ECRIS has been developed for the KEK digital accelerator [2] and is being operated without trouble over more than 1 year. Propagation of a msec-long ion pulse extracted with the ECRIS extraction voltage V1, is fully controlled by superimposing a rectangular-shape pulse voltage V2 (<0) on the fixed Einzel lens voltage V3 (V3 > V1). For most of time region (~msec), beam propagation is blocked, meanwhile for a time region (~5 μs), where V2 is on and V2 + V3 < V1, the beam can propagate downstream under the optimized transverse matching condition. Namely, the superimposed voltage V2 + V3 works as a gate voltage. This negative pulse voltage is produced by the solid-state switch driven Marx Generator, promising a fast rising/falling feature in the pulse profile. This chopper enjoys a lot of figure of merits originated from the fact that the beam can be handled at its minimum energy region:

low electron emission,
low voltage,
low energy X-ray, and
low cost.

This type chopper should be expected in a wide variety of ion beam applications. Comparison with other type choppers will be discussed.
[1] T. Adachi, K.W. Leo et al., "A Solid-state Marx Generator driven Einzel Lens Chopper", Rev. Sci. Inst. 82, 083305 (2011).
[2] T.Iwashita et al., "KEK Digital Accelerator", Phys. Rev. ST-AB 14, 071301 (2011).

Slides WEYO01 [5.566 MB]

Paper	Title	Page
WEYO01	The Einzel Lens Longitudinal Chopper	95
	K. Takayama, T. Adachi KEK, Ibaraki, Japan T. Adachi, K.W. Leo Sokendai, Ibaraki, Japan
	The Einzel lens longitudinal chopper [1] placed just after the ECRIS has been developed for the KEK digital accelerator [2] and is being operated without trouble over more than 1 year. Propagation of a msec-long ion pulse extracted with the ECRIS extraction voltage V1, is fully controlled by superimposing a rectangular-shape pulse voltage V2 (<0) on the fixed Einzel lens voltage V3 (V3 > V1). For most of time region (~msec), beam propagation is blocked, meanwhile for a time region (~5 μs), where V2 is on and V2 + V3 < V1, the beam can propagate downstream under the optimized transverse matching condition. Namely, the superimposed voltage V2 + V3 works as a gate voltage. This negative pulse voltage is produced by the solid-state switch driven Marx Generator, promising a fast rising/falling feature in the pulse profile. This chopper enjoys a lot of figure of merits originated from the fact that the beam can be handled at its minimum energy region: low electron emission, low voltage, low energy X-ray, and low cost. This type chopper should be expected in a wide variety of ion beam applications. Comparison with other type choppers will be discussed. [1] T. Adachi, K.W. Leo et al., "A Solid-state Marx Generator driven Einzel Lens Chopper", Rev. Sci. Inst. 82, 083305 (2011). [2] T.Iwashita et al., "KEK Digital Accelerator", Phys. Rev. ST-AB 14, 071301 (2011).
	Slides WEYO01 [5.566 MB]