Abstract
Space charge effect (SCE) along the beam line will decrease beam quality. Space charge compensation (SCC) with extra gas injection is a high-efficiency method to reduce SCE. In this paper, we will report the experimental results on the beam profile, potential distribution, beam emittance, and beam transmission efficiency of a 35 keV90 mA H beam and a 40 keV10 mA He beam compensated by ArKr. The influence of gas type, gas flow, and injection location will be discussed. Emphasis is laid on the consideration of SCC when designing and commissioning a high intensity ion beam injector. Based on measured data, a new definition of space charge compensation degree is proposed.
| Original language | English |
|---|---|
| Article number | 033304 |
| Journal | Review of Scientific Instruments |
| Volume | 84 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 2013 |
| Externally published | Yes |
Funding
This work was supported by the National Science Foundation of China (NSFC) Nos. 91126004, 11075008, and 11175009. Supported by the National Science Foundation of China, the ion source group at Peking University (PKU) built up a LEBT test bench to study the high intensity low energy ion beam SCC since 2007. In this paper, we shall focus on the relationship between injected gas flow and the beam quality improvement on a LEBT with magnetic lenses, as well as the definition of space charge compensation degree concept. In Sec. , we are going to give a brief description of the LEBT bench. In Sec. , details will be given on the key factors of SCC for the beam quality improvement. In Sec. , we shall introduce a more critical and more accurate space charge compensation degree concept with a local compensation degree η(r) and a whole beam compensation degree η to replace the previous one. The conclusions will be given at the end of this paper.
| Funders | Funder number |
|---|---|
| National Natural Science Foundation of China | 11175009, 11075008, 91126004 |
| Peking University |