Xiaotang Ren

Improvements of PKUAMS for precision 14C analysis of the project of Xia–Shang–Zhou Chronology

To meet the requirements of the Xia‐Shang‐Zhou Chronology project, an upgrade of the AMS facility at Peking University has been carried out, commencing in 1996, and a new sample preparation system with high eAciency and low memory has been set up in the Department of Archaeology. A NEC MC-SNICS ion source has been installed and the injection system has been reconstructed. Computer control of the beam line has been implemented using Group 3 ControlNet, and a new data acquisition system has been developed. The alignment and vacuum of the beam line have also been improved. The upgraded system was commissioned in 1998. Subsequent experience has led to eAcient procedures for beam tuning and 14 C/ 13 C measurement. A precision of 0.5% in the 14 C/ 13 C ratio has been achieved. Many samples have now been measured for the Xia‐Shang‐Zhou Chronology project. ” 2000 Elsevier Science B.V. All

A discussion on the application and production of metal ion beams.

Metal ion beams, which are used in surface modification of metals and alloys as ion beam micrometallurgy, are promising candidates for advanced applications in semiconductors and insulators. Doping with transition metal and rare-earth metal ions in semiconductors and insulators to form metallic nanoclusters attracted much more attention recently, since their applications in diluted magnetic semiconductors, electroluminescent devices, giant magnetic resistance, etc. In this paper, some experiments for metal ion beams will be presented, and various methods and technologies for the production of metal ion beams will be discussed.

DUHOCAMIS: A dual hollow cathode ion source for metal ion beams

In this paper we describe a novel ion source named DUHOCAMIS for multiply charged metal ion beams. This ion source is derived from the hot cathode Penning ion gauge ion source (JINR, Dubna, 1957). A notable characteristic is the modified Penning geometry in the form of a hollow sputter electrode, coaxially positioned in a compact bottle-magnetic field along the central magnetic line of force. The interaction of the discharge geometry with the inhomogeneous but symmetrical magnetic field enables this device to be operated as hollow cathode discharge and Penning discharge as well. The main features of the ion source are the very high metal ion efficiency (up to 25%), good operational reproducibility, flexible and efficient operations for low charged as well as highly charged ions, compact setup, and easy maintenance. For light ions, e.g., up to titanium, well-collimated beams in the range of several tens of milliamperes of pulsed ion current (1 ms, 10/s) have been reliably performed in long time runs.

A universal pocket PIG ion source with a permanent magnet

A universal pocket PIG ion source with a permanent magnet has been developed by our institute. Usually the source can produce single and multiple charged ions of gas or metal elements. At 20–30 kV extraction voltage, milliamperes of gas ions, and tens of μA of metal ions can be extracted with less than 50 W of discharge power consumption. And negative ions of some elements with larger electron affinity can be extracted directly from the source. Thus far, using LaB6 as a cathode, more than 50 μA of H−, about 1.4 mA of O−, and 1.8 mA of F− ions in total beam have been extracted at 15–20 kV extraction voltage. The power consumptions are less than 40, 50, and 100 W, respectively.

A versatile pocket PIG ion source with permanent magnet

Abstract A versatile pocket PIG ion source with permanent magnet is described in this paper. The source can produce both gas or metal and some negative ion beams. Normally 1–2 mA gas ion beams can be extracted at 40 W discharge power. Using Ar as auxiliary gas, tens of μA of solid or metal ions from cathode material are produced by cathode sputtering. The negative ions of some elements with larger electron affinity can be extracted from the source directly, so far using LaB 6 as cathode, more than 50 μA of H − , 1–2 mA of O − and F − ion beams have been extracted at 15–20 kV extraction voltage, the power consumption are normally less than 40, 50 and 100 W, respectively.

Development of ion sources for materials processing in china

This article reviews the development of ion sources for materials processing and the progress of commercial product of ion sources in China. The various ion-beam processing and the relative needs to ion sources are mentioned and discussed, such as ion sources with ion implantation, plasma immersion ion implantation, ion-beam-assisted deposition, ion-beam deposition, and so on. The states of progress for different kinds of ion sources specially for electron cyclotron resonance∕microwave, metal vapor vacuum arc, radio frequency (rf) ion source, end-Hall ion source, and cluster ion source, are given and discussed.

Metal Ion Sources for Ion Beam Implantation

In this paper a theme touched upon the progress of metal ion sources devoted to metal ion beam implantation (MIBI) will be reviewed. A special emphasis will be given to some kinds of ion sources such as ECR, MEVVA and Cluster ion sources. A novel dual hollow cathode metal ion source named DUHOCAMIS will be introduced and discussed.

A side extraction PIG negative ion source with a permanent magnet

A side extraction PIG ion source with a permanent magnet is introduced, which can be used not only for producing miliampere positive ion beams, but also for direct extraction of negative ions of some elements with larger electron affinity. So far H, O, and F negative ions have been extracted from the source. At −15 kV extraction voltage, O− ion beams of 130 μA and a F− ion beam of 75 μA are extracted, and the discharge power consumption is 110 and 280 W, respectively.