F. V. Moroz

Beta-decay energy measurements using total gamma-absorption spectroscopy

An application of the totalγ-absorption (TGA) spectroscopy to measurements of theβ-decay energies (Q) for nuclei far from stability is described. This approach provides theQ-values with accuracies up to 60 keV. TheQ values determined by this method at the IRIS facility for 64 nuclides in the mass region fromA=76 toA=165 are presented.

High temperature ion sources with ion confinement

Different types of high temperature ion sources such as surface, laser, and electron beam ionization ion sources have been developed and tested in off-line and on-line experiments. All types of developed ion sources have an essential common feature: an existence of the ion confinement inside the ion source cavity.

Fine-mesh photodetectors for CMS endcap electromagnetic calorimeter

The behaviour of fine-mesh vacuum phototriodes (VPTs) with the external diameters of 21 and 25 mm has been investigated in an axial magnetic field up to 4 T in view of their applications as readout devices for CMS Endcap Electromagnetic Calorimeter. The measured VPT parameters are: the photocathodes sensitivity and its homogeneity, the gain in zero and 4 T magnetic field at tilt angles corresponding to the pseudorapidity range of CMS ECAL Endcap 1.48–3.0 as a function of fine-mesh cell dimensions, excess noise factor and the stability of the photocathode response under the illumination by light emission diodes (LED) and the irradiation by 14 MeV neutrons. Phototriodes with 100 lines per mm fine-mesh and 25 mm external diameter are found to be the best candidates for coupling with rear PbWO4 crystals by dimensions of 30×30 mm, proposed to be used in CMS ECAL Endcaps. VPTs provide a gain of the order (6–8) in a 4 T magnetic field and an excess noise factor of 2–2.5 under illumination of a full photocathodes area.

Production of neutron rich nuclides from uranium carbide targets of different density

Abstract Online tests of uranium carbide targets of different density 11 and 1.25 g/cm3 coupled with a new type of high temperature electron beam ion source at a temperature of (2050–2300 °C) have been carried out. The yields of neutron rich isotopes of Mn, Fe, Co, Cu, Rh, Pd, Ag, Cd, In, Sn and isotopes of heavy elements such as Pb, Bi, Po and some others have been measured. Comparisons of the yields of Ag, In and Sn isotopes from tested targets are presented. In the temperature interval of (2100–2130 °C) the delay times for Ag and In were measured. The integral online production efficiency from the target – ion source unit estimated in the range (0.2–10%) for different nuclides.

Production of neutron-rich isotopes by one- and two-step processes in ISOL targets

The results are presented for an experiment that compares the difference between a one- and two-step reaction setup using 1 GeV protons. The rates of production from an on-line isotope separator target containing UCx are measured for isotopes in the neutron mass region of Rb and Cs. Some details about the measured results and predictions by the Monte Carlo models are discussed. The effects of the delayed release on the extracted efficiency are generalized using analytical models for application to a wide range of nuclear decay lifetimes.

Combined target-ion source unit for production of rare nuclides

A combined target-ion source unit (ionizing target) has been developed for the on-line production of radioactive single-charged ions. The target is able to withstand temperatures of up to 2500 °C and also acts as an ion source of surface, electron-beam, and laser ionizations. Using tantalum foil as a target material, the on-line combined target-ion source unit efficiency, which is the product of the ionization and release efficiencies, has been obtained for neutron-deficient isotopes of Eu, Gd, and Yb. These nuclides were ionized by the surface ionization inside a hot tungsten target container, holding tantalum foils as a target material. The results of the combined target-ion source unit use for on-line laser resonant ionization spectroscopy investigation of neutron-deficient Gd isotopes have been also presented. For neutron-rich isotopes produced from a high-density UC target, which were ionized by the surface ionization inside the target container, the ionization efficiency values have been obtained close to 100% for Rb and Cs and 10% for In. For Ag and Sn neutron-richisotopes, the values of the electron-beam ionization efficiency in the volume of the targetcontainer, correspondingly equal to 4% and 2%, have been obtained.

Development of high temperature targets at IRIS facility

Abstract High-temperature targets with different kind of target material, as tantalum foils, tungsten foils, NbC powder, TaC powder and UC powder have been developed and off-line and on-line tested. The yield and delay time measurements have been carried out for radioactive isotopes of Li, Rb and Cs.

High temperature electron beam ion source for the production of single charge ions of most elements of the Periodic Table

Abstract A new type of a high temperature electron beam ion source (HTEBIS) with a working temperature up to 2500 °C was developed for production of single charge ions of practically all elements. Off-line tests and on-line experiments making use of the developed ion source coupled with uranium carbide targets of different density, have been carried out. The ionization efficiency measured for stable atoms of many elements varied in the interval of 1–6%. Using the HTEBIS, the yields and on-line production efficiency of neutron rich isotopes of Mn, Fe, Co, Cu, Rh, Pd, Ag, Cd, In, Sn and isotopes of heavy elements Pb, Bi, Po and some others have been determined. The revealed confinement effect of the ions produced in the narrow electron beam inside a hot ion source cavity has been discussed.

Selective high temperature refractory target – laser ion source unit of IRIS facility

A high temperature refractory target (HTRT) specially designed for the suppression of the background of thermoion current coming from the target volume to the laser ion source has been off line and on line tested.

The radioisotope complex project “RIC-80” at the Petersburg Nuclear Physics Institute

The high current cyclotron C-80 capable of producing 40-80 MeV proton beams with a current of up to 200 μA has been constructed at Petersburg Nuclear Physics Institute. One of the main goals of the C-80 is the production of a wide spectrum of medical radionuclides for diagnostics and therapy. The project development of the radioisotope complex RIC-80 (radioisotopes at the cyclotron C-80) at the beam of C-80 has been completed. The RIC-80 complex is briefly discussed in this paper. The combination of the mass-separator with the target-ion source device, available at one of the new target stations for on-line or semi on-line production of a high purity separated radioisotopes, is explored in greater detail. The results of target and ion source tests for a mass-separator method for the production of high purity radioisotopes (82)Sr and (223,224)Ra are also presented.