* Corresponding author. Tel.: #36-52-417266/1088; fax: #36-52-416181. E-mail address: szabocs@moon.atomki.hu (C. Szabo H ). Vacuum 61 (2001) 391}396 Diagnostic research of highly ionized plasma generated by an ECR ion source Cs. Szabo H *, S. Biri, L. Kene H z, T. Suta, A. Valek University of Debrecen, DEBRECEN, Egyetem te & r 1, H-4031, Hungary Institute of Nuclear Research (ATOMKI), DEBRECEN, Bem te & r 18/C, H-4026, Hungary Babes-Bolyai University Cluj-Napoca, 3400, Str. Kogalniceanu Nr. 1, Romania Abstract One of the research directions of the ATOMKI-ECRIS is the systematic investigation of the con"ned plasma. In our laboratory we have the instrumentation background for two plasma research methods: X-ray and visible light diagnostics is possible outside the plasma chamber and the plasma can be investigated directly by movable Langmuir probes. Recently, a new research direction was started in order to produce plasmas and beams from high vapour pressure solid state samples. A special crucible was designed for the evaporation of the solid Zn, which can be moved along the axis of the plasma chamber. The position of the crucible in the plasma de"nes its temperature and thus the amount of the material injected into the plasma. In this paper we investigate the connection between the amount of the injected material into the plasma and the ion currents of the extracted ion beam. Further investigation of the plasma was carried out by taking numerous X-ray spectra and Langmuir probe characteristics.  2001 Elsevier Science Ltd. All rights reserved. Keywords: ECRIS; ECR plasma; Metallic plasma; Fullerene; Ion source; HCI 1. Introduction Research of metallic ECR plasmas is important for di!erent reasons. Our investigations of Zn plas- mas prepare the way for further metallic plasma investigations and later fullerene experiments, where gigantic molecules of 60 or more carbon atoms can be ionised and observed in the ECR plasma. Our aim was to "nd experimental methods for monitoring the appearance of massive particles in the plasma. A second goal was to compare the composition of the extracted beam with the com- position of the plasma. Zinc can be regarded as a massive particle in a pure nitrogen plasma. The injection of Zn into the plasma can be performed from a crucible heated by the plasma itself. This is the "rst time we have used this method in the ATOMKI-ECRIS. Earlier me- tallic plasmas were produced using a ferrocene con- tainer [1]. Among the new directions of applications of heavy ion sources, the investigation of fullerene (e.g. C  ,C  2 and other) ions is one of the most promising "elds. ECR ion sources can play an important role in the research of the properties of these big molecules and by possible production of endohedral fullerenes (X  C  where the fullerene 0042-207X/01/$-see front matter  2001 Elsevier Science Ltd. All rights reserved. PII:S0042-207X(01)00153-1