21st Century COE of Flow Dynamics
F2004 International Internship Program
Achievement Report
Date: February 10, 2005　　　
Name: Sooseok Choi

Academic year: 2004

Department: Nuclear Engineering

Institutions: Seoul National University

Research topic in International Internship Program: Control of reactive plasma jet impinging onto the substrate by using applied magnetic field and background pressure

Accepting supervisor in Tohoku University: Professor Hideya Nishiyama

Period of Internship： 　　　　12　/　01　/　2005　 〜 　11　/　02　/　2005
　　　　　　　　　　　　　　　　 Day　 Month　 Year　　　　Day　 Month 　Year
Date
 　　Itinerary during your stay in Japan (places of visit, etc.)
Jan. 12
Jan. 13
Jan. 14
Jan. 15
Jan. 20
Jan. 21
Jan. 25
Jan. 29
Jan. 28
Jan. 31
Feb. 03
Feb. 04
Feb. 05
Feb. 07
Feb. 08
Feb. 09
Feb. 10
Feb. 11
Arrival at Sendai and welcome party with the Electronic intelligent fluid laboratory members
Attending on the JSME fluid engineering division meeting
Introduction of Tohoku Univ., IFS and the 21st COE program by Prof. Nishiyama and tour of his laboratory
Viewing the Donto festival in the Hachimangu shrine with Prof. Nishiyama’s students.
Nabe party in the associate Prof. Sato’s house with the students
Experimental collaboration about the plasma controlling with company
Listening to Prof. Kamijo’s lecture about the rocket development in Japan.
Experimental collaboration about the plasma controlling with company
Attending on the International space university symposium
Visit to some laboratories at Aobayama campus (Fracture and Reliability Research Institute, Department of Electrical Engineering, Department of Quantum Science and Energy Engineering) with research associate Dr. Takana
Attending on Prof. Nishiyama’s laboratory regular seminar
My Seminar about diagnostics of thermal plasma jet
Listening to doctoral degree presentation of ‘Optimization of a DC-RF Hybrid plasma flow system for particle processing’ from Mr. Kawajiri
Attending on Prof. Nishiyama’s laboratory regular seminar
Attending on Prof. Nishiyama’s laboratory seminar
An excursion to Matsushima with Prof. Nishiyama’s laboratory members
Experimental collaboration about the plasma controlling with company
Listening to master degree presentation from Ms. Doi
Experimental collaboration about the plasma controlling with company
Listening to master degree presentation from Mr. Sawada
Listening to master degree presentation from Mr. Genta
Visit to Prof. Samukawa’s laboratory
Fare-well party with the Electronic intelligent fluid laboratory members
Return to Seoul

Outline the scientific activities you conducted while in Tohoku University (e.g. experiments, discussions, research trips)
　I participated the experiment about controlling of nonequilibrium plasma jet impinging onto the substrate by adjusting background pressure and applied magnetic field. In this experiment, we measure a light intensity of plasma jet, especially from nitrogen atom, and we succeeded to maintain uniform light intensity by using PID control method. This experimental result imply that, by means of PID control system we can effectively confine the nitrogen atoms in the plasma jet impinging on the substrate. Therefore, in material nitrating, high quality of surface treated products is expected from this experiment results.
　During the 21st century program, I visited some laboratories at Aobayama campus. Those belong to fracture and reliability research institute, department of electrical engineering and department of quantum science and energy engineering. The facilities are well appointed and the researchers are in full activity in their research field. Especially, I was very impressed from the research activities of plasma spray coating in the fracture and reliability research institute, because it is one of my interesting research field and I studied about manufacture of solid fuel cell (SOFC) by using plasma spraying for 2 years in Korea.
　Beside, I gave a seminar of my recent work which subject is diagnostics of thermal plasma jet by using an enthalpy probe method. Since the electrical intelligence fluid laboratory members are interested in enthalpy probe diagnostic system, I was very pleased.
Give your impressions of the present state of science in Tohoku University in your field
　Two years ago, I met professor Nishiyama and associate professor Sato in the international conference held in Jeju, Korea. From that time I have taken a growing interest in their research activities, because they are famous of computational and experimental analysis of thermal plasmas.
　In this visit, I can find their progressive research activities in plasma application field not only thermal plasma but also nonequilibrium low temperature plasma. And the super computer in IFS and unique experimental devices give me a great sensation.
　They have well trained staffs, excellent manpowers and effectively organized research system. In my opinion, they can make more fruitful results in their research field by more supporting such as financial support to master and doctoral course student and equipment of more advanced experimental devices comparing those in now.
Give your future plan of submitting a paper
A paper is not planned this time.
Give 21st Century COE of Flow Dynamics your comments or suggestions particularly with regard to the internship program
　I express my regret, since the length of my visit is too short as only a month, I can’t make completely satisfied results for you. In my opinion, at least 3 months are needed for successful internship program that can produce a valuable research result and a creative paper.
　On the other hand, I’m very pleased, and thank to you for giving me a great chance of research and living in Japan as the 21st century COE international internship program. This program is well prepared and very useful for foreign student.
　If more stipends were given to me, I could more comfortably live in Sendai. Frankly, about 2,000 yen for a day was insufficient for me.
General impression you had of Sendai and Japan during your stay
　To begin with, all of Japanese are very kind. By their favor, I can comfortably live in Sendai for a month. During my stay in Sendai, I can see great natural objects and beautiful traditions. Especially, traditional festivals and sightseeing on the Matsushima are very interesting for me. Probably, I can’t forget the impression from Japan and Sendai.