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The BEMS-2 on-line isotope separator operated in a heavy-ion beam employs a high-temperature surface-ionization ion source. The design features of the ion source with an external target are described. The recoil effect occuring in heavy-ion reactions is used to transport the radioactive isotopes under investigation into the source cavity through a 1.4 μm tantalum entrance foil. The operational characteristics of the ion source for Cs and Ba isotopes are studied. The average hold-up time of the activity in the ion source, τ, which is determined by the diffusion of recoils from the catcher, is measured. The value of τ depends on the temperature and type of the catcher used. For a tantalum catcher τ ≈ 1.0s at T = 2500°C, and the value of τ increases with decreasing temperature. In the case of a tungsten catcher, the hold-up time is several times longer. The ion source efficiency for Ba is equal to 30–50%.

Let us consider a function $$\begin{gathered} \varphi (z) = \min \max f_{ij} (z), \hfill \\ \begin{array}{*{20}c} --- \\ {j \in 1,N} \\ \end{array} \begin{array}{*{20}c} --- \\ {j \in 1,N_j } \\ \end{array} \hfill \\ \end{gathered} $$ where the functionsfij(z) are supposed to be continuously differentiable and real-valued on a set Ω ofEn,z∂En. The problem is to find maxzɛΩϕ(z). In this paper, it is proved that ϕ(z) is directionally differentiable. A necessary condition for a maximum is derived, and some numerical algorithms for maximizing ϕ are suggested. The results obtained can be applied for solving some problems in mathematical programming and control theory.

The report gives the calculation and the description of the mass separator of the LNR-JINR. The mass separator is made on the basis of a commercially available electromagnet with magnetic shims at the entrance and at the exit of the analyzer. The mass separator is designated to analyze nuclear reaction products with mass number up to M = 260. The report presents the ionoptical characteristics of the mass separator and the experimental results in a 205 Tl and 203 Tl isotope separation.

Most of the authors who admit the existence of a latent form of malaria require the following conditions to prove it: 1) intermittency of seizures, 2) their rapid disappearance from quinine, and 3) signs of chronic malaria preceding or accompanying the disease, with Laveran considering microscopic examination of the blood the best means for diagnosis.