Volume 71, Issue 2, February 2000
Index of content:
- ECR ION SOURCES (II)
71(2000); http://dx.doi.org/10.1063/1.1150333View Description Hide Description
The availability of highly charged ion sources (electron cyclotron resonance or electron beamion source) led in the last decade to many new scientific discoveries in various fields of atomic, solid state, and plasma physics. This article will review some of the most exciting results obtained in the field of the interaction of highly charged ions on surfaces in fundamental physics (hollow atom properties, mechanisms of electron captures and losses above, below, or at surfaceinteractions…) as well as in applied physics (surface modifications, lithography, etc.). The deceleration and monochromatization of the ion beams delivered by the ion sources will be discussed in the framework of their use in the study of the ion surfaceinteractions.
The contribution of the INFN-LNS to the development of electron cyclotron resonance ion sources (invited)71(2000); http://dx.doi.org/10.1063/1.1150334View Description Hide Description
The study of the axial injector for the superconducting cyclotron of the Laboratori Nazionali del Sud (LNS) began in 1989, with the aim of replacing the radial injection from a 15 MV Tandem with the injection by a modern electron cyclotron resonanceion source (ECRIS) which could be able to produce beams of highly charged ions to the same extent. The design of a superconducting ECRIS, named SERSE, was established in the two following years and funded since 1993, 2 yr before the extraction of the first beam from the cyclotron; the construction took more than 4 yr and in August 1997 SERSE, was ready in the test bench of CEA/DRFMC in Grenoble. The source was moved to LNS in May 1998 and since then it is operating with excellent results. During 1993–95, the concept of High B mode, on which SERSE was based, was tested at MSU-NSCL and the results have been applied to other sources, including the room temperature CAESAR that will share with SERSE the duty of the production of ions for the cyclotron. Even though the performances of this source are not comparable to the ones of SERSE, CAESAR is able to perfectly fulfill the ordinary request of our accelerator complex. The last project of LNS concerns the design of a scaled version of SERSE with higher field, to be operated at the gyrotron frequency (28 GHz or higher). The results of the existing sources will be reviewed, along with the main features of the new project.
71(2000); http://dx.doi.org/10.1063/1.1150335View Description Hide Description
Since the first Japanese electron cyclotron resonanceion sources (ECRISs) constructed, several tens of ECRISs have been used in many Japanese laboratories. Even if we choose the ECRIS which has an operational frequency higher than 6 GHz, 20 ECRISs are used for various purposes. At the end of the 1990s, three 18 GHz ECRISs were successfully operated and produced an intense beam of highly charged ions at JAERI Takasaki, NIRS and RIKEN; i.e., 1 mA of and of Various improvements to increase the beam intensity have been done, concerning the aluminum cylinder, biased electrode method. In the last decade, over 50 kinds of metallic ions have been produced from ECRIS using various methods. In 1998, we started to construct new superconducting ECRIS and to perform new experiments of mass spectrometry using ECRIS. This article will review the ECRIS progress and discuss the mechanism to increase the beam intensity of highly charged ions. We also describe a future plan and its new application in Japan.
Design of an electron cyclotron resonance ion source for the isotope separator and accelerator at TRIUMF71(2000); http://dx.doi.org/10.1063/1.1150336View Description Hide Description
A 2.45 GHz electron cyclotron resonanceion source has been designed and built to ionize radioactive atoms and produce single charged ion beams for the isotope separator and accelerator at TRIUMF. The source is characterized by its short axial length (8 cm) and the small pair of magnetic coils placed adjacent to the source cavity. A small diameter quartz tube is inserted in the cavity to confine the plasma to a small volume and to shorten total ion transient time for the exotic gaseous elements with short and intermediate half life. The computer code POISSON is used to design the magnetic coils. A three-electrode extraction system simulated with the code IGUNE is used to study the beam extraction efficiency. In this article the design of the source, extraction system, and the preliminary results on beam emittance and energy spread are presented; the results on ion transient time, ionization efficiency, and beam extraction efficiency are presented in a separate article.
71(2000); http://dx.doi.org/10.1063/1.1150337View Description Hide Description
Recent development of electron cyclotron resonance (ECR) ion sources in China is reviewed. Emphasis is put on high charge state ECR ion sources which have been mainly developed in China by Institute of Modern Physics (IMP). Presently two ECR ion sources built by IMP for highly charged ion beams are put into operation for cyclotrons and atomic physics research. The development of high charge state ECR ion sources at IMP has progressed with a new magnetic field configuration, better condition for extraction of highly charged ions, high mirrormagnetic field, large plasma volume, and special techniques to provide extra cold electrons. These techniques greatly enhance the production of highly charged ions from IMP ECR ion sources. So far more than of and of were produced by the IMP ECR ion sources. The metallic ion beam production was tested and the first beam was provided to the cyclotrons at IMP. The beam intensity of could reach The next part of this article will report the latest progress of 2.45 GHz ECR ion sources in China. A 2.45 GHz compact permanent magnetprotonion source was designed and constructed by IMP. A new microwave feeding system is applied on this ion source. The ion source is able to deliver 90 mA of mixed ion beam after preliminary commissioning. The article also mentions a small 2.45 GHz ECR ion source which was built by Sichuan University and used for industry applications. The dependence of plasma density and electron temperature on radio frequency power, neutral gas pressure, and different microwave windows was measured by a Langmuir probe on this ion source.