V. B. Kutner

Production of intense 48Ca ion beam at the U-400 cyclotron

Production of the intense accelerated 48Ca ion beam is the key problem in the experiments on synthesizing of new heavy nuclei. For this purpose an axial injection system with the electron cyclotron resonance (ECR)-4M ion source was created for the U400 cyclotron. The task was to achieve an accelerated beam with an intensity of 0.5 pμA of 48Ca5+ at the 48Ca consumption of ∼0.5 mg/h. To solve this problem, a new method for the solid material feed into the ECR source was developed. The combination of a micro oven with a hot tantalum sheet inside the discharge chamber allowed the production of intense beams of ions of metals with relatively low melting point. The present article describes the method, technique, and experimental results on the production of 48Ca ion beam at the U-400 cyclotron from the ECR-4M ion source. The analysis of the working substance balance in the ion source including the ion beam extraction and material regeneration is performed. The analysis based on the experimental data has shown ...

Design aspects and status of construction of the mVINIS ion source

The mVINIS ion source is a multiply charged heavy ion source based on the electron cyclotron resonance effect. This machine is a part of the Tesla Accelerator Installation, an ion accelerator facility whose construction has been going on at the VINCA Institute of Nuclear Sciences in Belgrade, Yugoslavia. mVINIS is an advanced version of the Dubna electron cyclotron resonance ion source 14-2, constructed at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. It is a complete injector, consisting of an ECR ion source, focusing and steering elements, an analyzing magnet, a vacuum system, and an ion beam diagnostic system. The main parts of mVINIS have been designed and manufactured at JINR, while the vacuum equipment, power supplies, ion beam diagnostics, and control system were purchased elsewhere. The preliminary testing (magnetic field measurements, vacuum testing, testing of the ECR ion source) has been performed at JINR, and the final assembly of the mVINIS and measurement of the ion beam ...

Performance of the ion source DECRIS-14-2

The Dubna electron cyclotron resonance ion source DECRIS-14-2 was put into regular operation at the U-400M cyclotron in the beginning of 1995. During the past two years the source has produced a wide range of ion beams for physics experiments as well as for the testing of the beam transport lines and the cyclotron itself. Ions of gases, such as He, N, O, Ne, and Ar were successfully delivered and accelerated in the cyclotron. The ion source has shown good performance especially in the case of middle charge state ions (e.g., 600 eμA of Ar8+) as well as high operational reliability. Significant progress in metal ion production has been achieved by introducing a new microoven for the evaporation of metal samples. This microoven in combination with an additional tantalum sheet installed inside the discharge chamber has made it possible to obtain Li2+ ion beams in excess of 200 eμA.

The laser ion source of multiply charged ions for the U‐200 LNR JINR cyclotron

Some results on the ion acceleration at the U‐200 cyclotron from the laser source are presented. The normal to the target surface was situated at a 45° angle to the magnetic field lines. A possibility is considered to create an ion laser source with plasma transport from a target to emission slit along magnetic field lines.

The efficiency of consuming rare isotopes in a PIG ion source

The efficiency of consuming a working substance in the cyclotron arc ion source during operation at the LNR JINR cyclotrons is analyzed in comparison with the results obtained for the ECR ion source of GANIL and the Berkeley cyclotrons. The experimental results described have been obtained during the acceleration of rare isotopes ion beams (Mg‐Ge) at the U‐400 and U‐300 cyclotrons. Some features of solid working substances fed into the cyclotron ion source are described. The optimal conditions for the efficient use of working substances in the arc discharge are discussed. The results of producing and accelerating rare gas isotopes ion beams, including the radioactive isotope carbon‐14, are presented. Prospects for the future development of efficient ion sources for the LNR cyclotron complex consisting of the U‐400 and the U‐400M are also discussed.

Intense high charge state ion sources (invited)

A review of Penning ionization gauge (PIG), duoplasmatron (DP), laser‐plasma ion source (LPIS), Electron cyclotron resonance ion source (ECRIS), and electron beam ion source (EBIS) used for the production of intense and high charge state ion beams is given. The outputs of high charge states of different elements of the Periodic Table from ion sources of these types are compared. Bare nuclei up to Ar can be obtained from EBIS and ECR and Xe+54 from EBIS. Comparisons are made of compilations of the output (high average current of 107–1017 pps) for different charge states of Xe for PIG, DP, ECRIS, EBIS ion sources and Ta, Pb for different charge states of the LPIS. The present level and perspectives of development (a pulsed gas feed, stationary electric field) of the PIG ion source are presented. The beam performance and future development of these intense and high charge state ion sources are discussed from the point of view of the perspectives of the cyclotron programs at FLNR and JINR.

Calculating method for confinement time and charge distribution of ions in electron cyclotron resonance sources

It is common knowledge that the electrostatic pit in a core plasma of electron cyclotron resonance sources exerts strict control over generation of ions in high charge states. This work is aimed at finding a dependence of the lifetime of ions on their charge states in the core region and to elaborate a numerical model of ion charge dispersion not only for the core plasmas but for extracted beams as well. The calculated data are in good agreement with the experimental results on charge distributions and magnitudes for currents of beams extracted from the 14 GHz DECRIS source.

The production of ions of solids from the PIG source with an additional anode

In this paper we report the results of production of ions of solids from the PIG source with an additional anode and solid material feed by cathode sputtering. The investigations were performed at the test bench and at the U‐400 cyclotron. Two versions of the ion source with different dispositions of the sputtering electrode were studied. In the first version the sputtering electrode is introduced into the discharge chamber through the wall opposite to the emission slit, the second version has lateral disposition of the sputtering electrode. The influence of the potential of an additional anode on the total extracted current and charge state distribution was studied at the test bench for both versions. The results of the test of the ion source with lateral disposition of the sputtering electrode at the U‐400 cyclotron are reported.

Source of multiply charged calcium and zinc ions

For the production of ions from solids in gas-discharge ion sources designed for mass separators and mass analyzers, there are two basic methods of introducing the materials in the discharge: evaporation of the operating material in a heated crucible at high temperatures [I] and cathode sputtering [2, 3]. There is a cyclotron lithium ion source which uses lithium vapor supplied from a special evaporator. A source where multiply charged ions are obtained from metals introduced in the discharge by cathode sputtering has been developed for American linear accelerators of multiply charged ions [4]. Sources where the operating material in vapor form is supplied by cathode sputtering have been developed in the JqNR Laboratory for Nuclear Reactions. The basic advantages and disadvantages of these methods were considered in [5].

Dubna electron cyclotron resonance ion source (DECRIS)‐14‐2: Results of the first operation

The new electron cyclotron resonance (ECR) ion source, the Dubna electron cyclotron resonanceion source (DECRIS)‐14‐2, was designed and built for use with the isochronous cyclotron U‐400M. The source assembly was completely finished by the end of 1994 and in January of 1995 the source was tested on the ECR‐test bench. In February the source was installed in the cyclotron and in April the first physical experiment on the accelerated beam was carried out. Here we present some design aspects of this source and the results of the first operation on the cyclotron.