CYCLOTRONS 2010 - List of Authors (Hu, C.D.)

Paper	Title	Page
MOPCP047	Analysis of Beam Quality Optimization of Bucket Ion Source	147
	Y.H. Xie, C.D. Hu, C.C. Jiang, L.Z. Liang, S. Liu, Y.L. Xie ASIPP, Hefei, People's Republic of China
	Funding: The National Nature Science Foundation of China (contract number: 10875146) The bucket ion source is widely used as the high energy beam source on the high power neutral beam injector system. A hot cathode bucket ion source is studied for the diagnostic neutral beam injector. The main parameters which influence the performance of bucket ion source are arc voltage, filament voltage, gas inlet rate and extracted voltage. In the experiment, only one parameter setting is varied when other parameter settings are fixed. The characteristics of ion source are got and the parameters setting valve are as follows: four filaments current from 500 A to 550 A, arc voltage from 120 V to 200 V, and ion source pressure during discharge is from 2.0 mTorr to 4.5 mTorr, extracted voltage from 40kV to 50kV. The arc current is higher than 100 A, and extracted beam current can reaches 6 A. Based on this, the arc efficiency, beam power deposition and beam proton ratio of ion source are analyzed and optimized. The proton ratio of extracted beam increased from 28 % to 40 %. It is very useful for the experimental operation and study about the bucket ion source.

MOPCP088	The Simulation on Beam Interaction with Background Particles	230
	C.D. Hu, L.Z. Liang, J.L. Wei ASIPP, Hefei, People's Republic of China
	Funding: Supported by the National Nature Science Foundation of China (10875146) and the Knowledge Innovation Program of the Chinese Academy of Sciences (Y05FCQ0128) A particle simulation with Monte Carlo was developed to study beam interaction with background particles in neutral beam injector. The collision processes associated with charge state change and reaction cross-section were analyzed for neutralization and re-ionization. Take the neutralization processes as a reference, for the positive arc discharge ion source, there are three different original ion species in the energetic ion beam. In evolution, a fast particle will suffer kinds of collisions decided by the collision cross-section or no impact within the target gas. Classify those collisions and their cross-sections according the change of charge state and momentum. Discretize the distribution of target gas density along the neutralizer properly. As a result, the neutralizer is divided into many extremely short segments averagely. So the gas density quantity at middle point can be regarded as that of each segment. According to the collision cross-section, select a random number to determine the evolution of particle states in each segments. With that particle simulation, the neutralization efficiency is estimated.

Paper

Title

Page

Analysis of Beam Quality Optimization of Bucket Ion Source

147

Y.H. Xie, C.D. Hu, C.C. Jiang, L.Z. Liang, S. Liu, Y.L. Xie
ASIPP, Hefei, People's Republic of China

Funding: The National Nature Science Foundation of China (contract number: 10875146)
The bucket ion source is widely used as the high energy beam source on the high power neutral beam injector system. A hot cathode bucket ion source is studied for the diagnostic neutral beam injector. The main parameters which influence the performance of bucket ion source are arc voltage, filament voltage, gas inlet rate and extracted voltage. In the experiment, only one parameter setting is varied when other parameter settings are fixed. The characteristics of ion source are got and the parameters setting valve are as follows: four filaments current from 500 A to 550 A, arc voltage from 120 V to 200 V, and ion source pressure during discharge is from 2.0 mTorr to 4.5 mTorr, extracted voltage from 40kV to 50kV. The arc current is higher than 100 A, and extracted beam current can reaches 6 A. Based on this, the arc efficiency, beam power deposition and beam proton ratio of ion source are analyzed and optimized. The proton ratio of extracted beam increased from 28 % to 40 %. It is very useful for the experimental operation and study about the bucket ion source.

MOPCP088

The Simulation on Beam Interaction with Background Particles

230

C.D. Hu, L.Z. Liang, J.L. Wei
ASIPP, Hefei, People's Republic of China

Funding: Supported by the National Nature Science Foundation of China (10875146) and the Knowledge Innovation Program of the Chinese Academy of Sciences (Y05FCQ0128)
A particle simulation with Monte Carlo was developed to study beam interaction with background particles in neutral beam injector. The collision processes associated with charge state change and reaction cross-section were analyzed for neutralization and re-ionization. Take the neutralization processes as a reference, for the positive arc discharge ion source, there are three different original ion species in the energetic ion beam. In evolution, a fast particle will suffer kinds of collisions decided by the collision cross-section or no impact within the target gas. Classify those collisions and their cross-sections according the change of charge state and momentum. Discretize the distribution of target gas density along the neutralizer properly. As a result, the neutralizer is divided into many extremely short segments averagely. So the gas density quantity at middle point can be regarded as that of each segment. According to the collision cross-section, select a random number to determine the evolution of particle states in each segments. With that particle simulation, the neutralization efficiency is estimated.