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CIPE Home Exchanges and Programs International Exchange Activities Institutional Program for Young Researcher Overseas Visits Reports by Researchers HU Zhimin

HU Zhimin

Department & title:
Graduate Student, Dept. of Applied Physics and Chemistry
The Queen's University Belfast
From 15 NOV. 2010 to 16 Dec. 2010

Research theme:Collaborative research work on apparatus making highly charged ions.

Summary of research activities during your overseas visit

Electron beam ion traps (EBITs) have been successfully used to study the physics of highly charged ions in extensively. In these machines, a high energy and current density electron beam creates, traps and excites the ions under study. The high current density is achieved through magnetic compression of the electron beam by a pair of super-conducting Helmholtz coils, arranged to allow spectroscopic access to the trap. At our laboratory (Nakamura’s laboratory ), there are two EBIT facilities which are Tokyo-EBIT and CoBIT. 

More recently, permanent magnet EBITs have been developed , with the advantages of decreased cost and size although with considerably lower specifications in terms of the current density, beam energy and vacuum quality. The newly-developed EBIT facility named Belfast-EBIT is located on the center for plasma physics of Queen's University Belfast in United Kingdom, and supervised by Dr. Fred Currell . The Belfast-EBIT belongs to this kind of facility.

Till now, there are many collaborative researches between the two laboratories. One of the ongoing themes is to study the correlation between the two-photon emissions in the dielectronic recombination process of the hydrogen-like ions that is a very interesting viewpoint for the basic atomic physics. The Belfast-EBIT has a character that is the X-ray emissions can be detected in a wide polarization angle besides azimuth angle, and this facility is suitable to study the correlation of two-photon emissions.

The construction of the facility has been accomplished, entered the commissioning stage. In this collaborative work, I did the testing works along with Dr. Fred Currell in the whole month. We prepared the electrical cables and necessary Vacuum for the operations. During the testing operation, we found many problems and solved them, and accumulated the valued experiences for the next target that is to acquire a high-current electron beam.

Research outcome obtained

The highly charged ion group at Queen’s University, Belfast (QUB) constructed a permanent magnet based EBIT, which additionally seeks to take advantage of opportunities offered by the permanent magnet structure. Several of these new characters make the device particularly suitable for the study of electron-ion interactions, although the machine has been designed to be versatile and capable of performing a wide range of studies.

Since the magnets are located outside the vacuum vessel, the trap to window distance has been reduced markedly. Furthermore, the permanent magnets do not need to be continuous rings to produce the desired field. Accordingly, magnet rings are designed to allow for detection of emitted photons at a range of angles (40º~140º) with respect to the electron beam propagation direction. The reconfigurable trap can accommodate in-situ detectors and in-line charged particle analyzers including an online analyzer to detect electrons resulting from various collision processes. In this way, electron energy loss spectroscopy may be performed on highly charged ion targets, giving rise to a new and complementary spectroscopic technique and providing a bridge between EBIT technology and traditional electron scattering techniques.

In this program, we have performed some testing operations at the newly-developed Belfast-EBIT facility, and obtained much valuable experience on the principle of the new type of EBIT (electron beam ion trap) facility. It is benefit to study the concerned atomic physics problem using the both EBITs of UEC and QUB. The deeper knowledge on the cooperative partner will promote and strengthen the research collaboration.

Reflection and suggestion on the program, particularly from the viewpoint of internationalization of researchers and students.

Queen’s University, Belfast (by the abbreviation QUB)is a member of the Russell Group of the UK's 20 leading research intensive universities, the Association of Commonwealth Universities, the European University Association, Universities Ireland and Universities UK. There are many outstanding scientists who have various origins in this University. United kingdom is the cradle of modern science. For a physics researches or student of science and engineering, these people are familiar: Isaac Newton, Henry Cavendish, James Clerk Maxwell, Michael Faraday, and so on. They are all the English origins, and the founders of the modern science. This program is the excellent opportunity to have a research experience which will be useful for my future study at UEC. It gave me an opportunity to have a touch with the occident science and culture. The collision of different cultures will bring unexpected rewards.

By the exchange with the overseas universities, the reputation and influence of UEC will be promoted. It is consistent with UEC international Strategy.

Created: December 16, 2010 / Last modified:November 15, 2012