ECRIS2012 - List of Authors (Biri, S.)

Paper

Title

Page

Two-frequency Heating Technique for Stable ECR Plasma

10

A. Kitagawa, M. Muramatsu
NIRS, Chiba-shi, Japan
S. Biri, R. Rácz
ATOMKI, Debrecen, Hungary
T.F. Fujita
National Institute of Radiological Sciences, Chiba, Japan
Y. Kato
Osaka University, Graduate School of Engineering, Osaka, Japan
N. Sasaki, W. Takasugi
AEC, Chiba, Japan

As a method to improve highly charged ion production, a technique to feed multiple microwaves with different frequencies is well-known. However the reason is not made sufficiently clear. Our group studied with two frequencies close together with a power of 600 W over by 18 GHz NIRS-HEC ECR ion source installed in the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). As a result, it was revealed that the improvement of output beam current depends on the total power. In this case it seems that the two-frequency heating technique carries the advantage that the plasma instability at high microwave power is relieved. The effectiveness of an additional microwave depends on its frequency. It is necessary to optimize an additional frequency precisely; several tens MHz step against 18 GHz. The optimized frequency is directly influenced by the magnetic configuration. The necessary requirements for an additional microwave and the procedure of optimization in order to obtain a large advantage will be discussed.

Slides TUXO03 [1.590 MB]

WEXO02

Recent Developments and Electron Density Simulations at the ATOMKI 14.5 GHz ECRIS

77

S. Biri, R. Rácz
ATOMKI, Debrecen, Hungary
J. Pálinkás
University Debrecen, Debrecen, Hungary

The 14.5 GHz ECR ion source of ATOMKI is a standard room-temperature ECRIS devoted for plasma diagnostic studies, for atomic physics research and also serves as a particle source with wide range of elements for surface treatments. From the beginning lots of technical modifications and developments have been carried out on the ion source. The changes aimed the increasing of the beams charge, intensity and the widening of the ion choice. Other modifications were done to develop special, non-standard operation modes or to produce peculiar plasmas or beams. Recently the original NdFeB hexapole was exchanged by a new one and new iron plugs were calculated, designed and installed at the injection side of the source. The resulted stronger magnetic trap has shown significant effect on the beam intensity and on the charge states distribution. The new magnetic configuration was re-calculated by the TrapCAD code developed by our group. The spatial movement and energy evolution of a high number of electrons were followed in the calculation. A post-calculation energy filtering carried out for the lost and non-lost electrons reveals numerous interesting and important information in 3D.

Slides WEXO02 [11.678 MB]

Paper	Title	Page
TUXO03	Two-frequency Heating Technique for Stable ECR Plasma	10
	A. Kitagawa, M. Muramatsu NIRS, Chiba-shi, Japan S. Biri, R. Rácz ATOMKI, Debrecen, Hungary T.F. Fujita National Institute of Radiological Sciences, Chiba, Japan Y. Kato Osaka University, Graduate School of Engineering, Osaka, Japan N. Sasaki, W. Takasugi AEC, Chiba, Japan
	As a method to improve highly charged ion production, a technique to feed multiple microwaves with different frequencies is well-known. However the reason is not made sufficiently clear. Our group studied with two frequencies close together with a power of 600 W over by 18 GHz NIRS-HEC ECR ion source installed in the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). As a result, it was revealed that the improvement of output beam current depends on the total power. In this case it seems that the two-frequency heating technique carries the advantage that the plasma instability at high microwave power is relieved. The effectiveness of an additional microwave depends on its frequency. It is necessary to optimize an additional frequency precisely; several tens MHz step against 18 GHz. The optimized frequency is directly influenced by the magnetic configuration. The necessary requirements for an additional microwave and the procedure of optimization in order to obtain a large advantage will be discussed.
	Slides TUXO03 [1.590 MB]

WEXO02	Recent Developments and Electron Density Simulations at the ATOMKI 14.5 GHz ECRIS	77
	S. Biri, R. Rácz ATOMKI, Debrecen, Hungary J. Pálinkás University Debrecen, Debrecen, Hungary
	The 14.5 GHz ECR ion source of ATOMKI is a standard room-temperature ECRIS devoted for plasma diagnostic studies, for atomic physics research and also serves as a particle source with wide range of elements for surface treatments. From the beginning lots of technical modifications and developments have been carried out on the ion source. The changes aimed the increasing of the beams charge, intensity and the widening of the ion choice. Other modifications were done to develop special, non-standard operation modes or to produce peculiar plasmas or beams. Recently the original NdFeB hexapole was exchanged by a new one and new iron plugs were calculated, designed and installed at the injection side of the source. The resulted stronger magnetic trap has shown significant effect on the beam intensity and on the charge states distribution. The new magnetic configuration was re-calculated by the TrapCAD code developed by our group. The spatial movement and energy evolution of a high number of electrons were followed in the calculation. A post-calculation energy filtering carried out for the lost and non-lost electrons reveals numerous interesting and important information in 3D.
	Slides WEXO02 [11.678 MB]