The paper describes the design and operating principle of a valve designed for testing the prototypes of key elements of a massive gas injection system: a seat and a supersonic nozzle. The calculation results for supersonic nozzle parameters close to optimal for the selected valve design have been presented. The simulation of gas flows through the seat and nozzle was carried out, the parameters of the formed jet at the injection system outlet in the nozzle near field were calculated. The choice of the "stepped" nozzle profile for the first tests was justified. An assessment was made of the requirements for the accuracy of manufacturing prototype nozzles.

The diagnostic of the peripheral plasma parameters in terms of the relation of lines of neutral helium is included in the diagnostic complex of the tokamak Globus-M2. The first measurements of the peripheral plasma parameters are performed near the lower X point. The measured spatial distributions of the electron temperature and density are in satisfactory agreement with the simulation with the SOLPS-ITER code.

The report presents the results of simulations of plasma disruption in the T-10 tokamak using the ASTRA code, including discharges with a disruption being initiated by the massive gas injection (MGI). This study focuses on the development phase of thermal quench, and the effect of different channels of heat loss during quench evolution is examined. It is shown that the initial phase of the slow phase of thermal quench can be described by the selection of sources and transport coefficients.

Precursor recognition methods in vector signals of plasma diagnostics are presented. Their requirements and possible options for their development are considered. In particular, the variants of using symbolic regression for building a plasma disruption prediction system are discussed. The initial data preparation using correlation analysis and symbolic regression is discussed. Special attention is paid to the possibility of using algorithms in real time.

In this paper, we present the first, after replacing a graphite limiter with a tungsten limiter, experimental results of the regimes of improved plasma confinement in the T-10 tokamak when injecting deuterium pellets. Comparison with the results of previous experiments with a graphite limiter shows the preservation of the improved confinement effect. Preliminary results of the experiments on the change in poloidal angle of injection of pellets allow us to say that with the central injection, the maximum effect of improved confinement is observed.

The article presents the results of experimental studies and modelling of chord pellet injection in the T-10 tokamak plasmas. The deviation of pellets at different angles up to the peripheral injection does not result in their substantial degradation for speeds of approximately 600 m/s. The concepts of co- and counter-pellet-injection relative to the direction of rotation of the tokamak plasma are introduced. With an increase of the angle of pellet deviation, a substantial increase in the front duration and in the decay of bursts of radiation intensity of the deuterium D alpha atom line was observed experimentally, and the simulations demonstrate an increase in the amplitude of the occurring radial electric field.

Cрывы разряда в крупных токамаках и будущих реакторах являются серьёзной проблемой, ограничивающей срок их службы.Представлены результаты исследований влияния напуска благородных газов на динамику развития срыва разряда в токамаке Т-10.Срывы разряда вызывались разными способами: наращиванием плотности плазмы до предельной и/или инжекцией дейтериевой или примесной (углеродной) макрочастицы.Инжекция благородных газов (гелия, аргона или ксенона) проводилась как в стационарной стадии для инициации срыва разряда, так и во время спада тока.Обнаружено, что спад тока при срыве разряда в Т-10 происходит в две фазы (медленную и быструю), отличающиеся существенно разным характерным временем.Инжекция дейтериевых макрочастиц при параметрах имеющегося инжектора не влияет на динамику спада тока, а массивный напуск благородных газов при выcоком давлении приводит к переходу спада тока из медленной фазы

Cylindrical cryogenic targets are required to carry out the Laboratory Planetary Science scheme of the experiments of the High Energy Density matter Generated by Heavy Ion Beams collaboration at FAIR. In this paper, for the first time a thorough analysis of the problem of such targets' fabrication, delivery and positioning in the center of the experimental chamber has been made. Particular attention is paid to the issue of a specialized cryogenic system creation intended for rep-rate supply of the High Energy Density matter Generated by Heavy Ion Beams experiments with the cylindrical cryogenic targets.

The paper addresses the issue of a specialized cryogenic system (SCS) creation for carrying out the experiments in the field of High Energy Density matter generated by heavy ion beams (HEDgeHOB). Theoretical and experimental studies have been performed in the following directions: target fabrication, target manipulation, and target survival. As a result, a reliable way for the SCS creation has been proposed.

Two separate topics on a pellet injection activity at the multimirror trap GOL-3 are presented. The first topic is connected with studies of influence of a high-energy-density plasma on solids. A carbon pellet of 2-mm diameter was injected into the plasma for this purpose. The second discussed topic is a status of works on a cryogenic pellet injector for plasma fueling at GOL-3.

Introduction This paper describes effects of neutral beam injection (NBI) into the spherical tokamak Globus-M [1,2]. First NBI experiments [3] demonstrated significant, by a factor of 3, increase of the ion temperature in the plasma bulk at moderate values of the plasma average density. The neutral beam heating experiment was continued in 2004 – 2005 campaign with the NB power comparable with the Ohmic one. The experiments were performed in extended range of the plasma densities and beam energies. The target plasma had following parameters: toroidal magnetic field B0 = 0.4 T; plasma major radius R = 0.33–0.35 m; minor radius a = 0.22–0.23 m; vertical elongation k = 1.5– 1.8. New experimental data were obtained by means of improved diagnostics (Thomson scattering, magnetic measurement reconstruction, etc.). The neutral beam was co-injected tangentially to a circumference of the radius Rs = 30 cm. The typical output power varied in the range of 0.3 to 0.7 MW and depended on the beam energy. The injector construction made possible to change the beam energy step by step in the range of 20–30 keV. The experimental equipment layout is shown in fig. 1.

This contribution presents recent results obtained with a pyroelectric bolometer installed on the Globus-M spherical tokamak. By results of processing signals, the information about a time lag between signals of different channels was received, using a correlation analysis. This part of work is aimed to estimate a velocity of macroscopic movements of radiation sources. Radiation losses during recent experiments with NBI and ICRH operation are presented and considered as well.

A pellet injection technique is used at GOL-3 multimirror trap for the solution of several physical problems. Earlier use of small impurity pellets (CH 2, LiD) for the purposes of plasma diagnostics and for formation of de ns plasma bunch inside the main plasma column was already discussed (see, e.g. [1]). Here two other topics of the pellet injection activity are presented. The first topic is connected with continuing reacto r-relevant studies of influence of a highpower pulsed stream of electron-hot plasma on solids (see, e.g., [2]). The new problem of expansion of dense target plasma along the magnetic field through a distance of several meters was investigated. A carbon pellet of 2-mm diameter was injected into the plasma for this purpose. The pellet was large enough that no full evaporation of graphite occured. Specific energy load was ~50 MJ/m . Parameters of the carbon plasma during its expansion were studied. Similar behaviour of surface plasma can be in reactor-class tokamaks at fast dump of energy during ELM events. Other physical problem for pellet injection is th e increase in plasma density near the axis of GOL-3. The status of works on cryogenic pelle t injector, which is developed jointly by BINP and SPbSPU is presented.

Fig.1. L-H transition in the NBI heated Globus-M shot # 19518 First results on H-mode generation in the Globus-M spherical tokamak V.K. Gusev 1 , B.B. Ayushin 1 , F.V. Chernyshev 1 , V.V. Dyachenko 1 , V.G. Kapralov 2 , G.S. Kurskiev 1 , R.G. Levin 1 , V.B. Minaev 1 , A.B. Mineev 3 , M.I. Mironov 1 , M.I. Patrov 1 , Yu.V. Petrov 1 , V.A. Rozhansky 2 , N.V. Sakharov 1 , I.Yu. Senichenkov 2 , O.N. Shcherbinin 1 , S.Yu. Tolstyakov 1 , V.I. Varfolomeev 1 , A.V. Voronin 1 , E.G. Zhilin 4

This contribution presents recent results of pellet technologies development for plasma fuelling in magnetic confinement machines with open or closed magnetic configuration. The current status of ITV7 pellet injector for GOL3 multimirror linear machine, PGS2.2 pellet guide system of ITV4 in-situ pellet injector for TUMAN-3M tokamak and ITV5 centrifuge pellet injector for Globus-M spherical tokamak is reported New results on modeling of tangential pellet injection into TUMAN-3M tokamak are discussed as well.

The Globus-M spherical tokamak is a low aspect ratio (R/a~1.5) device. It is equipped with the neutral beam injection system for the auxiliary plasma heating. In the 2004 campaign the investigation of the neutral beam heated plasmas in Globus-M was continued. To increase the output neutral beam power the upgrade of the injector was made. As a result the injector is able to produce 0.5-0.7 MW neutral beam (up to 30 keV, 30 ms). The aim of the program was to optimize target plasma parameters in order to increase the absorbed beam power. The experiments were performed in the range of plasma current 0.18- 0.22 MA, and the plasma density (1-4)× 1019 m-3 in a low toroidal magnetic field ~ 0.4 T near the plasma axes. The experiments were preceded by installation of additional graphite tiles in the divertor region. Vacuum vessel boronization was performed before the second series of experiment. The experimental data from routine (D-alpha, interferometer, NPA, SXR and HXR monitors, magnetic probes, EFIT) and advanced (radar-reflectometer, SXR array) diagnostics are presented in the paper as well as the results of the numerical simulation.