IPAC2011 - List of Authors (Lu, P.N.)

Paper	Title	Page
MOPS034	Progress on Space Charge Compensation Study in Low Energy High Intense H⁺ Beam*	676
	P.N. Lu, Z.Y. Guo, S.X. Peng, Z.X. Yuan, J. Zhao PKU/IHIP, Beijing, People's Republic of China H.T. Ren Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China
	This article lays emphasis on the relationship between the Space Charge Compensation (SCC) and the beam quality in different conditions. Ar and Kr are used to compensate a 35keV/90mA H⁺ beam with the gas pressure from 3.7×10^-4 Pa to 6×10^-3 Pa. Experiments are conducted in different compensation states with three approaches. With an energy spectrometer, we have got the energy spectra of Extra Compensation Gas Ions (ECGI). By a beam profile meter, the beam profiles are obtained when the injection of compensation gas is gradually rising. In the meantime, the beam emittance is measured under different compensation conditions. After measurements of the above data, the potential and the rest charge distributions in the beam are calculated by analyzing the ECGI energy spectra and beam profiles. All experiments performed aimed to seek out the best circumstance for SCC dominated low energy high intensity ion beams.together to calculate the potential distribution are calculated by analyzing the energy spectra and beam profiles. All experiments performed aimed to seeking for the best circumstances in SCC dominated low energy high intensity ion beams.

THPS021	Methods to Obtain High Intensity Proton Ion Beams with Low Emittance from ECR Ion Source at Peking University	3463
	H.T. Ren Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China J.E. Chen, Z.Y. Guo, P.N. Lu, S.X. Peng, Z.Z. Song, J.X. Yu, M. Zhang, J. Zhao, Q.F. Zhou PKU/IHIP, Beijing, People's Republic of China
	Funding: Supported by the National Science Foundation of China 11075008. With the development of accelerator technology, to obtain an ion beam with high intensity and low emittance is becoming one of the main goals of research for ion sources. At Peking University we have developed several 2.45 GHz electron cyclotron resonance (ECR) ion sources for different projects and we paid close attention to the beam intensity increasing as well as the beam emittance reduction. Methods are adopted to improve beam intensity by increasing the density of plasma inside the discharge chamber, optimizing the geometry pinch effect and the perveance at the extraction aperture. To suppress the emmitance increasing of an extracted beam, the shape of the electrodes as well as the voltage of suppression electrode are carefully selected With these efforts, a 120 mA total proton beam has been extracted from the permanent magnet ECR ion source at 50 kV, and the measured normalized rms emittance is less than 0.2 pi.mm.mrad. The beam current density at the extraction aperture is about 420 mA/cm².

Paper

Title

Page

Progress on Space Charge Compensation Study in Low Energy High Intense H⁺ Beam*

676

P.N. Lu, Z.Y. Guo, S.X. Peng, Z.X. Yuan, J. Zhao
PKU/IHIP, Beijing, People's Republic of China
H.T. Ren
Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China

This article lays emphasis on the relationship between the Space Charge Compensation (SCC) and the beam quality in different conditions. Ar and Kr are used to compensate a 35keV/90mA H⁺ beam with the gas pressure from 3.7×10^-4 Pa to 6×10^-3 Pa. Experiments are conducted in different compensation states with three approaches. With an energy spectrometer, we have got the energy spectra of Extra Compensation Gas Ions (ECGI). By a beam profile meter, the beam profiles are obtained when the injection of compensation gas is gradually rising. In the meantime, the beam emittance is measured under different compensation conditions. After measurements of the above data, the potential and the rest charge distributions in the beam are calculated by analyzing the ECGI energy spectra and beam profiles. All experiments performed aimed to seek out the best circumstance for SCC dominated low energy high intensity ion beams.together to calculate the potential distribution are calculated by analyzing the energy spectra and beam profiles. All experiments performed aimed to seeking for the best circumstances in SCC dominated low energy high intensity ion beams.

THPS021

Methods to Obtain High Intensity Proton Ion Beams with Low Emittance from ECR Ion Source at Peking University

3463

H.T. Ren
Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China
J.E. Chen, Z.Y. Guo, P.N. Lu, S.X. Peng, Z.Z. Song, J.X. Yu, M. Zhang, J. Zhao, Q.F. Zhou
PKU/IHIP, Beijing, People's Republic of China

Funding: Supported by the National Science Foundation of China 11075008.
With the development of accelerator technology, to obtain an ion beam with high intensity and low emittance is becoming one of the main goals of research for ion sources. At Peking University we have developed several 2.45 GHz electron cyclotron resonance (ECR) ion sources for different projects and we paid close attention to the beam intensity increasing as well as the beam emittance reduction. Methods are adopted to improve beam intensity by increasing the density of plasma inside the discharge chamber, optimizing the geometry pinch effect and the perveance at the extraction aperture. To suppress the emmitance increasing of an extracted beam, the shape of the electrodes as well as the voltage of suppression electrode are carefully selected With these efforts, a 120 mA total proton beam has been extracted from the permanent magnet ECR ion source at 50 kV, and the measured normalized rms emittance is less than 0.2 pi.mm.mrad. The beam current density at the extraction aperture is about 420 mA/cm².