중이온 가속기용 낮은 에너지 빔 광학계 설계 연구: The design of low energy beam transport for heavy ion accelerator

by Jungbae Bahng (MS Candidate)

Wednesday May 8, 2013, 9:00 AM → 11:00 AM Asia/Seoul

201-4호 (제1과학관)

The design of low energy beam transport system (LEBT) which is the between electron cyclotron resonance (ECR) ion source and acceleration system for heavy ion accelerator was studied. ECR ion source at the front of the LEBT system is a device for generation of multi-charged ion beams using magnetic mirror effect.
When beams are generated from ECR ion source, unexpected charged particles produced at the same time. Therefore, beams are required to be separated and selected for accelerating through the LEBT system. Low energy beam in the LEBT system has a large emittance and space-charge effect due to the slow velocity.
The space charge effect is caused by the charged particles distributions. which make the electrical repulsion by coulomb force. So beam size becomes bigger.
Using TRANSPORT code, designed beam envelope was within 4 cm and the magnet's length, radius, strength, arrangement and array are optimized. In order to check beam transport including space charge effect, beam tracking was simulated by using IMPACT-Z code. The emittance growth of lithium and uranium beam as a result of tracking simulation were little changed 4.4 % and 0.06 %, respectively and transmission is 100 %. Designed the LEBT system has many characteristics such as good beam selection by using a dipole magnets and slits, high transmission.
The LEBT system design and matching acceptance of RFQ(Radio Frequency Quadrupole) accelerator was simulated by using TRANSPORT code and IMPACT-Z code.

Thesis Advisor: Prof. Eun-San Kim