V. N. Loginov

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.

Experimental Tests of the Modernized VASSILISSA Separator (SHELS) with the Use of Accelerated 50 Ti Ions

A high intensity ion beam of 50Ti ions was obtained using the ECR ion source on the U400 cyclotron. The experimental tests using accelerated 50Ti ions were performed with a modernized VASSILISSA separator (SHELS). Data has been obtained on the transmission coefficients of recoil nuclei synthesized in complete fusion reactions. Estimates from ion optical calculations performed in the design phase of the project of modernizing the separator are completely confirmed.

PRODUCTION AND ACCELERATION OF TRITIUM ION BEAM AT THE U-400M CYCLOTRON

The tritium ion beam was required for study of 4H and 5H resonance states in neutron transfer reactions t+t→5H+p and t+t→4H+d. Experiments were performed at the separator ACCULINNA [1]. In the report the main aspects of the tritium ion beam production and the result of the cyclotron operation are presented.

Electron cyclotron resonance ion source DECRIS-4 for the U400 cyclotron

The electron cyclotron resonance ion source DECRIS-4 has been designed and constructed at the FLNR to be used as a second injector of heavy multiply charged ions for the U-400 cyclotron. After the modification of the injection side this source can be also used as a “charge breeder” (the “1+→n+” method) for the second phase of the Dubna radioactive ion beams project. The main feature of the ion source design is the creation of the extended resonance zone in a comparatively compact electron cyclotron resonance ion source. For this purpose the axial magnetic field is formed with a flat minimum. In this case the superposition of the axial magnetic field and the radial field of the permanent-magnet hexapole, made from NdFeB, allows one to create a larger resonance volume. For the plasma heating a microwave frequency of 14 GHz is used. In this paper we will present the basic design features of the ion source, including the results of the magnetic-field measurements. Some preliminary results of ion source tests ...

Results of the ECR ion sources operation at the FLNR (JINR) cyclotrons

In the report the main results on production of ion beams from the ECR4M and DECRIS-14-2 ion sources will be presented. Many of the elements required for acceleration at the FLNR cyclotrons are available in the solid state. For production of these beams the evaporator and MIVOC technique were used. In the report the main emphasis is given to production of ions of enriched isotopes, such as 26Mg, 48Ca, 58Fe.

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.

Development of ECR multicharged ion sources for accelerators

Several types of ECR ion sources for production of intense multicharged ion beams of gaseous and solid materials in the mass range He - Bi with the intensity more than 1mA (for Ar8+) are described. The axial magnetic field is created by the water cooled copper coils, or superconducting coils. The radial magnetic field is created by the permanent magnet (NdFeB) system. For the plasma heating a microwave generators with the frequency of 14 GHz or 18GHz are used.

Status report on electron cyclotron resonance ion source operation at the Flerov Laboratory of Nuclear Reactions (Joint Institute for Nuclear Research) cyclotrons

Two electron cyclotron resonance (ECR) sources, DECRIS-14-2 and ECR4M, are presently in permanent operation at the Flerov Laboratory of Nuclear Reactions cyclotrons, U400M and U400, respectively. A wide range of ions of gases from He up to Xe was delivered by the sources and accelerated in the cyclotrons. Major efforts were made in the production of high current stable ion beams of solids with relatively low melting points in mass ranges from Li up to Bi. Both the evaporator and the MIVOC technique were used. Among the solids a beam as exotic as 48Ca was produced at the U400 cyclotron with high efficiency. The main results on production of ion beams of gases and solids are reported. For further development of ECR ion sources a test bench was designed and built. The test bench is equipped with the new DECRIS-3 ion source. The parameters of the test bench and ECR source are described.