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Studies of the relaxation and confinement of hot anisotropic ions are considered to be the key elements of the gas dynamic trap (GDT) experimental research programme. The method of confinement study described consists essentially in the comparison of measured ion parameters with those predicted by computer simulations. To realize this approach a set of diagnostics for the measurements of local and global parameters of the fast ions has been developed. In particular, this set includes diagnostics to measure the local energy and the angular distribution functions. For numerical studies of the fast ion dynamics a Monte Carlo code based on the theory of two body Coulomb collisions has been elaborated. Comparison of the experimental data with the results of the simulation clearly demonstrates that the fast ion characteristic relaxation times in the warm target plasma are close to those determined by binary Coulomb collisions. Significant anomalous energy losses or scattering of fast ions have not been observed as yet. The measurements provide a maximum density of the fast ions with mean energy of about 8 keV up to 10E+13/cm^3, in good agreement with computer simulations. The increase of the neutral beam power and improved vacuum conditions of GDT made possible the access to plasma ß of as high as 30%.

Fast Ti-deposition was applied in the gas-dynamic trap (GDT) facility in the regimes with 14–17.5 keV, 2.5–4 MW neutral beam (NB) injection to control gas recycling at the first wall and thereby reduce charge-exchange losses of energetic ions. The charge-exchange losses of the fast ions turned out to be much less than in former, non-conditioned discharges. The temporal and spatial variation of the neutral gas density was measured during typical shots and compared with the results obtained by means of a Monte Carlo transport code. The comparison of the numerical results with the experimental data shows that the recycling coefficient of the chamber wall which has been freshly coated by titanium is close to that of the pure metallic surface.

Within the framework of an Institutional Partnership of the Alexander von Humboldt Foundation, the Budker Institute of Nuclear Physics Novisibirsk (BINP) and Forschungszentrum Dresden-Rossendorf worked together in a joint project devoted to the research at the coupled GDT-SHIP facility of the BINP with the focus on the study of plasma phenomena within the SHIP mirror section. The project began at July 1st, 2005 and ended on August 30th, 2008. It included work packages of significant theoretical, computational and analyzing investigations. The focus of this final report is on the presentation of results achieved whereas the work that was done is described briefly only. Chapter 2 illustrates the GDT-SHIP facility and describes shortly the planned topics of the SHIP plasma research. Chapter 3 explains the main extensions and modifications of the Integrated Transport Code System (ITCS) which were necessary for the calculations of the fast ion and neutral gas particle fields in SHIP, describes briefly the scheme of computations and presents significant results of pre-calculations from which conclusions were drawn regarding the experimental program of SHIP. In chapter 4, the theoretical and computational investigations of self-organizing processes in two-component plasmas of the GDT-SHIP device are explained and the results hitherto achieved are presented. In chapter 5, significant results of several experiments with moderate and with enhanced plasma parameters are presented and compared with computational results obtained with the ITCS. Preparing neutron measurements which are planned for neutron producing experiments with deuterium injection, Monte Carlo neutron transport calculations with the MCNP code were also carried out. The results are presented. Finally, from the results obtained within the joint research project important conclusions are drawn in chapter 6.

In the last decade, a great progress was made in developing projects of sub-critical fission systems dedicated to transmutation of nuclear waste. In contrast to a fission reactor, such a device is fed with neutrons from an outer source in order to sustain a steady-state power generation. The Budker Institute of Nuclear Physics has made the proposal of a powerful 14 MeV neutron source based on a gas dynamic trap (GDT). This neutron source is primarily thought as irradiation facility for fusion material research. So, the question raises, whether the GDT based neutron source could be a candidate to efficiently drive such a sub-critical system too. The contribution pursues this question using results of first neutron transport calculations. The calculations were made for a simplified model of an actinides burner, which has been developed for an international benchmark exercise performed under the auspices of the Nuclear Energy Agency (NEA) of the Organization for Economic Cooperation and Development (OECD). Important parameters of the burner are compared for two cases - when driven by a spallation or by the GDT neutron source. From this comparison some advices for further improvements of the GDT neutron source are concluded.

The concept of the Synthesised Hot Ion Plasmoid (SHIP) experiment at the gas dynamic trap (GDT) facility of the Budker Institute Novosibirsk was already presented at the 29th EPS Conference. During the last year several numerical simulations were made by means of the Integrated Transport Code System (ITCS) to determine the best experimental scenario for getting high plasma parameters. This contribution presents important results of the recent numerical simulations of SHIP by means of the ITCS modules which had to be partly modified.

At present, the GDT facility of the Budker Institute Novosibirsk, which is an axially symmetric magnetic mirror device of gas dynamic trap type, is being upgraded. The first stage of the upgrade is the Synthesised Hot Ion Plasmoid (SHIP) experiment. The experiments will be performed in a small mirror section that is installed at one side of the GDT. The magnetic field on axis will be in the range of 1-7 T and the mirror ratio will amount 1.2-1.4. The mirror is filled with background plasma streaming in from the central cell. Two neutral beam injectors perpendicularly inject a total current up to 120 equ. Amperes of hydrogen atoms with an energy of 25 keV as pulse with a duration of about 1 ms. Ionisation of the beams generates the high-energetic ion component with the high density and mean energy about 17 keV. The plasma bata ~ 0.8. This contribution explains the concept of the SHIP experiment and presents the results of SHIP simulation. The first experimental activity is also presented., 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France)

Recently, a plasma with energetic deuterons has been produced in the gas dynamic trap (GDT) experiment under skew injection of 4 MW, 15–17 keV deuterium neutral beams. The GDT is a long, axially symmetric magnetic mirror device with a high mirror ratio. The deuterium neutral beams have been injected at the mid-plane of the device under 45° to the axis. High anisotropy of the fast ion angular distribution results in a strong peaking of the fast ion density at the turning points near the end mirrors. The axial profile of DD fusion product fluxes has been measured and found to be strongly peaked in the same regions. The characteristics of the profiles are consistent with the classical mechanism of fast ion relaxation caused by two-body Coulomb collisions with plasma particles. This observation validates an approach used in a GDT based neutron source, in which the regions of high neutron flux would be surrounded by the testing zones for fusion material irradiations.

GDT experiments of significance to a GDT based neutron source development are reported in the areas of generation of axially peaked neutron flux profile, stable confinement with on-axis plasma beta ~40%, and radial electric field control. Skew injection of 4 MW 15-17 keV deuterium neutral beams into central cell resulted in generation of strongly peaked axial profile of neutron flux density. This can be described by a model of fast ion relaxation, which involves classical mechanisms of electron drag and binary ion-ion collisions only. Experiments with the radial limiter biasing show that the plasma density profile and radial losses respond to the electric field profile. An increase of plasma energy was achieved with increased magnetic field in the central cell and optimised radial profile of electric field. In these regimes the on-axis plasma beta near the turning points of fast deuterons exceeded ~40%. The plans for future upgrade of the GDT device are discussed. It suggests considerable increase of NB injected power (up to 10 MW) and extension of the pulse duration from 1 ms up to 3-5 ms. After the upgrade, a significant increase of the electron temperature up to 250-300 eV could be obtained. Properties of the plasma with parameters approaching those in the full-scale neutron source are planned to study in experiments with NB injection into an additional mirror cell which will be installed near to one of the standard mirror coils.

At present, the GDT facility of the Budker Institute for Nuclear Physics Novosibirsk is being upgraded. The first stage of the upgrade is the Synthesised Hot Ion Plasmoid (SHIP) experiment. It aims, on the one hand, at the investigation of plasmas the parameters of which are expected to appear in the region of high neutron production in a GDT based fusion neutron source as proposed by the Budker Institute and, on the other hand, at the investigation of plasmas the parameters of which have never been achieved before in magnetic mirrors. The expected record values of plasma parameters and several peculiarities of the plasma offer a great field for interesting investigations. In order to simulate the particle fields inside the GDT device and later in a GDT based neutron source an Integrated Transport Code System (ITCS) is being developed in collaboration between Forschungszentrum Rossendorf and Budker Institute. It consists of modules which allow the calculations of neutral gas, background plasma and of the fast ion component considering their mutual interactions. This contribution explains the concept of the SHIP experiment and presents the results of first calculations by means of the ITCS modules.

The Budker Institute Novosibirsk made a proposal for a highly intense neutron source on the base of a gas dynamic trap. It is mainly intended for fusion material irradiation. The gas dynamic trap is an axisymmetric open system with a high mirror ratio for the confinement of a collision dominated plasma and a high-energetic ion component which is fed by an oblique neutral beam injection. In addition to research at the experimental facility of the Budker Institute an Integrated Transport Code System is under development in collaboration with the Forschungszentrum Rossendorf. It is to calculate the relevant physical effects connected with the target plasma, fast ions, neutral gas and the neutrons appearing inside the central cell of the device. The paper briefly describes the functions of the main modules and reports on the first exercise devoted to the planned upgrade of the facility.

The Budker Institute of Nuclear Physics Novosibirsk develops a project of an intense 14 MeV neutron source (NS) based on a gas dynamic trap (GDT) which is mainly intended for fusion material irradiation. Its actual disadvantage is the lack of data for the parameter range of the projected GDT-NS which does not yet allow a reliable interpolation from the parameters of the existing GDT experimental facility to the neutron source. At present, experimental and computational researches are carried out to complete the required data base. So far, rather promising results have been achieved concerning the main plasma-physical issues like MHD stability, longitudinal confinement, cross-field transport and the fast ion behaviour [1,2]. For the investigations in the latter field the Integrated Transport Code System (ITCS) has been used [3,4]. These investigations must be extended to a higher level of plasma parameters. To this end a substantial upgrade of the GDT facility is planned. The main subsystems which are to be upgraded are the neutral beam injection (NBI) system and the magnetic field power supply. The higher power and the longer duration of the injection will provide a substantially higher energy content of the fast ions and, consequently, will increase the electron temperature. During the last years several transport codes have been developed and applied for computational studies in parallel to the experimental research. They have been coupled by appropriate data file transfers to the ITCS. The report is focused on the application of the code system to study possible operation regimes of the upgraded GDT. The results of numerical simulations enable us to conclude that an electron temperature of 250-300 eV can be achieved in the GDT-Upgrade with a NBI of 10 MW and a duration of 3-6 ms. The maximum fast ion density in the region of their turning points is estimated at ~5x1013 cm-3.

Experiments with 3 MW deuterium injection have been carried out in the Gas Dynamic Trap (GDT) to simulate the axial profile of the fusion reaction intensity in the proposed neutron source based on the GDT. Quite narrow angular distribution function of the fast ions produced by an oblique neutral beam injection results in a peaked axial profile of the fusion yield. This strong peaking is essential to produce an intense neutron flux in the testing zones of the GDT-based neutron source. The scintillation counters were installed in the central cell of the device to monitor the DD fusion reaction products: neutrons (2.45 MeV) and protons (3,02 MeV). They were closely located to the plasma column inside of the vacuum chamber in oreder to avoid contribution from the scattered neutrons and to improve the spatial resolution of the measurements. The axial profiles of the fusion neutrons and protons have been measured in the high-beta regime of the GDT operation. In the paper the experimental data are compared with the results of numerical simulations. The conclusion may be drawn that the kinetics of the fast ion relaxation and scattering is determined by classical Coulomb collisions.

The Budker Institute of Nuclear Physics Novosibirsk proposed a highly intense 14 MeV neutron source on the base of a gas dynamic trap (GDT). The GDT is an axisymmetric mirror plasma device. In case of the complete effectiveness at the necessary parameters this type of neutron source promises several advantages in comparison to other proposals. Its actual disadvantage is the incomplete data basis which does not yet allow a reliable interpolation of its feasibility. To close this gap is the goal of the experimental and computational research presently being under way. Here the Monte Carlo codes TUBE for the hydrogen gas and MCFIT for the fast ions which have been developed by Forschungszentrum Rossendorf in collaboration with the Budker Institute take an important part. The paper shortly describes the MCFIT code, compares some numerical with measured results and draws certain conclusions.

The confinement of the fast, anisotropic ions is one of the basic objectives of the GDT experimental research program. The approach consists in comparing the measured ion parameters with those predicted by computer simulations based on the theory of Coulomb collisions. A broad set of diagnostics for measurements of fast ion parameters has been developed. In particular, it includes the measurement of the local energy distribution function. In parallel the Monte Carlo transport code FIT, which simulates fast ion histories in the frame of the lassical theory has been developed. The comparison of the measured and computed parameters clearly shows that the energy confinement time of the fast ions is governed by Coulomb collisions only and significant anomalous ion losses were not yet observed in GDT experiments up to the present plasma parameters.

The behaviour of the fast ion population is one of the crucial issues of the GDT based neutron generator project proposed by the Budker Institute Novosibirsk. Therefore, the study of the fast ion dynamics is one of the main research objectives at the GDT facility. This research is supported by computational investigations by means of codes that have been specially developed. The present paper briefly describes the fast ion code, demonstrates the capabilities of a fast ion and neutral gas code package and draws computational and physical conclusions from calculations of recent experiments.

The effect of wall conditioning on a plasma was studied in the Gas Dynamic Trap (GDT) facility by means of titanium coating of the containment wall. After depositing titanium on the inner surface of the vacuum chamber the charge-exchange losses of the fast ions turned out to be much less than in former, non-conditioned discharges. The temporal and spatial variation of the neutral gas density was measured during typical shots and calculated by means of a Monte Carlo transport code. The comparison of the results numerical simulation with the experimental data are presented.

Based on the Integral Transport Method the code NEUSI calculates the radial-, axial- and time-dependent distributions of fast and slow hydrogen atoms and hydrogen molecules in the plasma region of the GDT facility of the Budker Institute Novosibirsk. The presented poster briefly describes the basic features and approximations of the code and gives some calculation results.

The Gas Dynamic Trap (GDT) is an axisymmetric mirror device with a high mirror ratio to confine a collisional plasma and a minority of fast ions. The latter are produced in the trap by oblique, high-power neutral beam (NB) injection into the collisional target plasma. The recent upgrade of the NB system resulted in an increase of the power maximum during the pulse from 2.5 to almost 4.5 MW. Under the new experimental situation were studied: the transport and stability of the high-ß plasma, the cross-field tranport and the detailed energy balance of the fast ions. The paper reports on the measurement techniques used and on the results achieved.

This report summarizes the results of experimental investigations obtained during the last five years at the Gas Dynamic Trap experimental facility of the Budker Institute Novosibirsk. Due to an essential upgrade of the main components performed in this period, the following plasma parameters have been achieved: electron temperature - 90-110 eV, fast ion density - up to 0.8*10^13 cm^-3, mean energy of fast ions - 5-8 keV, plasma-ß - 15-20%. The paper describes the following investigations: effect of wall conditioning on neutral gas dynamics, longitudinal electron heat flux, confinement of the high-ß two-component plasma, fast ion parameters under high-ß conditions, fueling of the target plasma by gas puffing. It presents results of measurements and of calculations.

A system of electric arc evaporators for fast Ti-coating has been installed inside the gas dynamic trap (GDT) of the Budker Institute Novosibirsk. In this way the vacuum conditions could be substantially improved and consequently the plasma parameters especially those of the fast ions remarkably increased. The fast ion lifetime raised up by more than one order of magnitude. Under the new conditions special experiments were carried out to study the neutral gas dynamics inside the GDT and to compare with numerical results which were obtained by means of the Monte Carlo code TUBE.

By upgrading the high-energetic neutral beam injection system of the gas dynamic trap (GDT) experimental facility of the Budker Institute Novosibirsk the plasma heating could be substantially improved. Now an electron temperature up to 120 eV is attainable compared to 70 eV before. Under the new conditions various heating scenarios and the plasma confinement were studied.

The Gas Dynamic Trap (GDT) of the Budker Institute Novosibirsk is an axisymmetrical plasma mirror device with a mirror ration in the range of 12.5-100. It confines a cold and dense target plasma in a collisional regime and a minority of fast ions in a kinetic regime. The target plasma flows out of the central chamber into external MHD-stabilizers where the curvature of the magnetic field lines is favourable with respect to stability against curvature driven MHD flute modes. The research programme of the GDT facility is focused on the generation of the plasma physical data base that is necessary for the GDT based neutron source project proposed by the Budker Institute. The paper reports on the recent upgrade of the neutral beam injection system and on the new plasma parameters achieved by that.