Multiply charged ions from solid substances with the mVINIS Ion Source

We have used the well known metal-ions-from-volatile-compounds (MIVOC) method at the mVINIS Ion Source to produce the multiply charged ion beams form solid substances. Based on this method the very intense and stable multiply charged ion beams of several solid substances having the high melting points were extracted. The ion yields and the spectra of multiply charged ion beams obtained from solid materials like Fe and Hf will be presented. We have utilized the multiply charged ion beams from solid substances to irradiate the polymers, fullerenes and glassy carbon at the low energy channel for modification of materials.13th International Conference on Physics of Highly Charged Ions, Aug 28-Sep 01, 2006, Queens Univ, Belfast, Irelan

Effects of the Ar ions pre-amorphization of Si substrateon interface mixing of Fe/Si bilayers

Ion beam mixing of Fe/Si bilayers, induced by 100 keV (40)Arions at room temperature was investigated. Rutherford backscattering spectroscopy (RBS), atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were applied for structural characterization. The main focus of this study was on the influence of the substrate structure on interface mixing. The influence of the substrate structure is due to the two classes of irradiated bilayers, Fe thin films deposited on crystalline or pre-amorphized Si substrates. An about 76% higher efficiency of atomic transport across the pre-amorphized Fe/a-Si interface as compared to that of Fe/c-Si bilayers was observed

Structural deformation in Hf2Ni observed by TDPAC method

The electric quadrupole interaction in Hf2Ni was measured at 181Ta probe using the time-differential perturbed angular correlation method (TDPAC) in the temperature range 78 to 1314 K. Analysis of the obtained spectra revealed the presence of a single nuclear quadrupole interaction (NQI) and its linear descending dependence with increasing temperature. In the region 1134 to 1314 K, the presence of structural deformation is evident from the coincidence spectra.YUCOMAT 2007 : 9th Annual Conference YUCOMAT 2007 : Programme and the book of abstracts; September 10-14, 2007; Herceg Novi, Montenegr

Hyperfine interactions at 181Ta solute in ferromagnetic Hf-Ni alloys with low concentration of Hf atoms

We have measured hyperfine interactions of 181Ta probe in the polycrystalline 0.2at.%Hf-Ni, 2at.%Hf-Ni and 5at.%Hf-Ni alloys, by the time differential perturbed angular correlation (TDPAC) method at room temperature (RT). The hyperfine magnetic field (Hhf) in 0.2at.%Hf-Ni alloy at the 181Ta probe is 8.66(1)T, where the small atomic concentrations of Hf atoms mainly substitute on Ni host lattice sites. Three hyperfine interactions were detected in two other alloys. In the 2at.%Hf-Ni alloy, we found existence of Larmor precession frequency ωL (1)=536(2)Mrad/s at the 181Ta probe surrounded by Ni atoms and the second electric quadrupole interaction (EQI) ωQ (2)=2.20(2)Mrad/s at the 181Ta probe in new formed HfNi5 intermetallic phase. The third EQI ωQ (3)=137.4(1)Mrad/s corresponds to the small amount of monoclinic HfO2 phase contamination at T<900K. In the 5at%Hf-Ni alloy, magnetic dipole interaction (MDI) at the 181Ta probe is ωL (1)=536(6)Mrad/s, while the second EQI at the site of the same probe in HfNi5 is ωQ (2)=2.24(2)Mrad/s. The presence of ωQ (3)=128(1)Mrad/s at the 181Ta probe originating from HfO2 contamination is in good accordance with earlier published results for this phase.52. konferencija ETRAN-a : Jun 8-12, Palić, 2008

Hyperfine interactions at 181Ta solute in ferromagnetic Hf-Ni alloys with low concentration of Hf atoms

We have measured hyperfine interactions of 181Ta probe in the polycrystalline 0.2at.%Hf-Ni, 2at.%Hf-Ni and 5at.%Hf-Ni alloys, by the time differential perturbed angular correlation (TDPAC) method at room temperature (RT). The hyperfine magnetic field (Hhf) in 0.2at.%Hf-Ni alloy at the 181Ta probe is 8.66(1)T, where the small atomic concentrations of Hf atoms mainly substitute on Ni host lattice sites. Three hyperfine interactions were detected in two other alloys. In the 2at.%Hf-Ni alloy, we found existence of Larmor precession frequency ωL (1)=536(2)Mrad/s at the 181Ta probe surrounded by Ni atoms and the second electric quadrupole interaction (EQI) ωQ (2)=2.20(2)Mrad/s at the 181Ta probe in new formed HfNi5 intermetallic phase. The third EQI ωQ (3)=137.4(1)Mrad/s corresponds to the small amount of monoclinic HfO2 phase contamination at T<900K. In the 5at%Hf-Ni alloy, magnetic dipole interaction (MDI) at the 181Ta probe is ωL (1)=536(6)Mrad/s, while the second EQI at the site of the same probe in HfNi5 is ωQ (2)=2.24(2)Mrad/s. The presence of ωQ (3)=128(1)Mrad/s at the 181Ta probe originating from HfO2 contamination is in good accordance with earlier published results for this phase.52. konferencija ETRAN-a : Jun 8-12, Palić, 2008

Optimization of the mVINIS ion source extraction system

The ion-optical properties of the single gap extraction system of the mVINIS ion source are investigated. The pepper-pot method was used to measure the effective emittances of the ion beams extracted from the plasma. The emittances have been analyzed as functions of the extraction electrode position for various charge states of the ion species. (C) 2004 American Institute of Physics.10th International Conference on Ion Sources, Sep 08-13, 2003, Dubna, Russi

Acceptance of the channel for modification of materials (L3A) of the Tesla accelerator installation

The channel for modification of materials (L3A) of the Tesla Accelerator Installation, in the Vinca Institute of Nuclear Sciences, connected to the mVINIS ion source, consists of an ion beam transport line and an interaction chamber enabling the ion beam assisted deposition. The 8.4 m long beam line, starting at an analyzing slit after an analyzing magnet, contains two electrostatic quadrupole triplet lenses: a 90degrees bending magnet and an electrostatic beam scanner. The maximal beam transmission coefficient, e.g., for 60 keV N4+ beam, has not exceeded 30%. At the time the beam line was designed, the mVINIS ion source was not commissioned, so that the emittances of the beams it delivered were underestimated. This is one of the reasons for the low transmission performance of the beam line. In this article the results of the beam line acceptance calculations are presented and compared with the measured beam emittances. The calculations are based on the transfer matrix formalism with no space charge taken into account. The suggestions for improving the beam transmission performance of the beam line are given. (C) 2004 American Institute of Physics.10th International Conference on Ion Sources, Sep 08-13, 2003, Dubna, Russi

Recent results with the mVINIS ion source

The mVINIS ion source is a part of the TESLA Accelerator Installation, in Belgrade. It is an ECR ion source used as a stand-alone machine delivering multiply charged ion beams to a low energy experimental channel for modification of materials (the L3A channel). In the future, it will be also used as a heavy ion injector for the VINCY Cyclotron. In this article we present the recently introduced hardware and software changes resulting in an improved operation of the mVINIS: the emittance measurement system, the inlet system for precious gases, the improved control system of the microwave generator, a new power supply for the injection stage coil, and the improved program for recording and analysis of the ion beam spectra. (C) 2004 American Institute of Physics.10th International Conference on Ion Sources, Sep 08-13, 2003, Dubna, Russi

Effects of 200 keV argon ions irradiation on microstructural properties of titanium nitride films

This paper reports on a study of microstructrual changes in TiN/Si bilayers due to 200 key Ar+ ions irradiation at room temperature. The 240 nm TiN/Si bilayers were prepared by d.c. reactive sputtering on crystalline Si (100) substrates. The TiN films were deposited at the substrate temperature of 150 degrees C. After deposition the TiN/Si bilayers were irradiated to the fluences of 5 x 10(15) and 2 x 10(16) ions/cm(2). The structural changes induced by ion irradiation in the TiN/Si bilayers were analyzed by Rutherford Backscattering Spectroscopy (RBS), X-ray diffraction analyses (XRD) and Transmission Electron Microscopy (TEM). The irradiations caused the microstructrual changes in TiN layers, but no amorphization even at the highest argon fluence of 2 x 10(16) ions/cm(2). It is also observed that the mean crystallite size decreases with the increasing ion fluence. (C) 2011 Elsevier B.V. All rights reserved.5th International Conference on Elementary Processes in Atomic Systems (CEPAS), Jun 21-25, 2011, Belgrade, Serbi

Production of multiply charged ion beams from solid substances with the mVINIS ion source

The mVINIS ion source has enabled us to obtain multiply charged ion beams from gases as well as from solid materials. The solid substance ion beams were produced by using two techniques: (a) the evaporation of metals by using the inlet system based on a minioven and (b) the metal-ions-from-volatile-compounds method (MIVOC) by using the modified gas inlet system. Great efforts were made in the production of high current stable ion beams of solids with relatively C ion-beam current of over 300 mu A was one of the most high melting points (over 1000 degrees C). The B3+ intensive beams extracted until now. The obtained multiply charged ion-beam spectra of solid substances (B, Fe, and Zn) are presented as well as some of the corresponding experimental results achieved during the modification of polymers, carbon materials, and fullerenes. (c) 2006 American Institute of Physics.11th International Conference on Ion Sources, Sep 12-16, 2005, Caen, Franc