A. Droździel

Arc discharge ion source for europium and other refractory metals implantation

The best method for the impurity doping to the host material is the ion implantation. Due to high melting point of the rare earth standard metal ion sources are useless. One of the solution is to use chemical compounds of rare earths characterized by low melting point. In this paper we describe the novel design of the ion source suitable for refractory metal (e.g., rare earths) ion implantation. The dependencies of Eu(+) current on cathode and arc currents as well as on hydrogen flow are presented. Europium (III) chloride as the source of the europium atoms was used. Europium ions were produced during collisions of evaporated and decomposed EuCl(3) molecules with fast electrons. The typical current of the europium ion beam extracted from the ion source was 25 microA for the extraction voltage of 25 kV. The ion source works without maintenance breaks for approximately 50 h, which enables high dose implantation. The presented ion source needs neither advanced high power supplies nor high vacuum regime.

Extraction of ions from a plasma source and formation of beams

The current of ions extracted from a plasma source has been measured as a function of extraction voltage Ue. Comparison of the obtained characteristics to theoretical predictions has shown that the experimental data agree with the Child-Langmuir theory only within a certain range of Ue. The results of our measurements and computer simulation of the ion-beam profile allowed the assessment of the parameters of the ion-emitting surface and the average ion energy in the plasma of the source under study.

Simulations of ionization in a hot cavity surface ion source

A new numerical Monte Carlo method based model of a hot cavity surface ionization ion source is presented in this paper. The model, intended to support the studies on ionization phenomena in a widely used class of ion sources, takes into account geometry of the ion source and extraction system, ionizer temperature and other features. The results of ion source efficiency calculations for various configurations of the extraction field are reviewed. The dominant role of the ionizer region near the extraction opening is described. Simulated dependences of ionization efficiency on the working parameters like ionizer length and temperature, ionization potential of the substance, and extraction voltage are discussed. A good agreement of the experimental data (e.g., influence of ionizer temperature, current-voltage curve) and the predictions of the model is found. It is also shown that the contribution to the ionization yield from impact of thermionic electrons accelerated by the extraction field may be significant, especially for the substances of small surface ionization coefficient. The simulation results are compared to the predictions of different theoretical models of the ion source--the obtained simulation data are in accordance both with a well-known Kirchner formula and the so called spherical ionizer model.

Plasma ion source with hollow cathode

Abstract The paper describes a plasma ion source for ionization of low-volatile elements of a high ionization potential. The source is characterized by a high operation temperature and relatively effective ionization. Plasma in a closed volume of the hollow cathode is produced by thermoemission electrons and ionized atoms dosed to the source or diffused from the walls of heated cathode. The construction of the source makes its operation possible in electromagnetic isotope separators on-line, e.g. on a beam of highly energetic protons of YASNAPP facility (Nucl. Instrum. Methods B70 (1992) 62).

Production of Molybdenum and Tantalum Ion Beams using CCl2F2

Conformal Invariance and Conserved Quantities for Lagrange Equation of Thin Elastic Rod Peng Wanga,∗, Hui-Rong Feng and Zhi-Mei Lou School of Civil Engineering and Architecture, University of Jinan, Jinan, Shangdong, 250022, P.R. China College of Transportation and Civil Engineering, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, P.R. China Department of Physics, Shaoxing University, Shaoxing, Zhejiang, 312000, P.R. China

Negative ion beams from a plasma type source with additional surface ionization

The universal variant of the ion source is now operational in the mass separator of the Institute of Physics, M Curie-Sklodowska University. The source produces a wide range of ion beams, both negative and positive. Special emphasis has been given to the ionization processes taking place in the device. The source design and selected examples of its characteristics are given.