University of Chinese Academy of Sciences, Beijing, People's Republic of China
PKU, Beijing, People's Republic of China
Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China
The multi-component ion beam is very common in nuclear physics, materials physics and most kind of ion source. But the diagnosis of multi-component ion beam [1] can be difficult because of its complex composition and irregular energy-dispersion. We need an effective way to analyzing the multi-component ion beam. There is a multi-component ion beam whose total beam current varies from 1 mA to 50mA and the beam energy can be 20keV to 150keV. In this paper, four methods to analyzing this multi-component ion beam are described, which are Faraday cup array method, fluorescent screen with Faraday cup, movable aperture with conductive fluorescent screen, and current calibration method, respectively. The distributions and currents of the separated ion beams are obtained by means of the four methods, and the current and energy-dispersion of each component might be measured at the same time. This is of special interest for beams with multi-components. Detailed description and comparison of the four methods are discussed in this paper.
Correspondence Author:Peng ShiXiang.
Email: sxpeng@pku.edu.cn
PKU, Beijing, People's Republic of China
IMP, Lanzhou, People's Republic of China
The beam dynamic design of a 100 mA, 162.5 MHz Radio Frequency Quadrupole (RFQ) is presented in this paper. The RFQ will accelerate protons from 85 keV to 3 MeV under the operation mode of continuous-wave (CW). The code PARMTEQM is used to carry out the beam dynamics design and the transmission efficiency has been optimized and improved to more than 99%. In the design of this high-current linac, the space charge effect is analyzed as it can cause emittance growth, nonuniform particle density distribution and resonance effect. The electrode structure parameters generated by PARMTEQM also be adopted by the code of Toutatis to verify the result’s veracity.
PKU, Beijing, People's Republic of China
A new combined accelerator that couples radio frequency quadrupole (RFQ) and separated function radio frequency quadrupole (SFRFQ) in a single cavity has been designed and manufactured. Recently, the performance of the cavity under high RF power was tested with an upgraded RF power source. The inter-vane voltages of both RFQ section and SFRFQ section were measured by using high purity germanium detector and the corresponding measurement system. The measured shunt impedance is about 546.9 kΩ•m, which means the cavity needs 19.5 kW for the designed inter-vane voltage of 65 kV. The results are well consistent with the cavity design.
PKU, Beijing, People's Republic of China
University of Chinese Academy of Sciences, Beijing, People's Republic of China
In a high intensity volume-produced H− ion source, H− ion production processes are great affected by electron temperature and gas pressure distribution within the discharge chamber. The H-/e ratio within an extracted H− ion beam is much depended on the electron absorption within the extraction system. At Peking University (PKU), lots of experiments were carried out for better understanding H− processes and electron dump on our 2.45 GHz microwave driven Cs-free permanent magnet volume-produced H− source. Detail will be given in this paper.
Author to whom correspondence should be addressed. Electronic mail:
sxpeng@pku.edu.cn.