Time evolution of spin state of radical ion pair in microwave field: An analytical solution

The paper reports an exact solution for the problem of spin evolution of radical ion pair in static magnetic and resonant microwave field taking into account Zeeman and hyperfine interactions and spin relaxation. The values of parameters that provide one of the four possible types of solution are analysed. It is demonstrated that in the absence of spin relaxation, besides the zero field invariant an invariant at large amplitudes of the resonant microwave field can be found. The two invariants open the possibility for simple calculation of microwave pulses to control quantum state of the radical pair. The effect of relaxation on the invariants is analysed and it is shown that changes in the high field invariant are induced by phase relaxation.Comment: 18 pages, 7 figure

Study of high temperature and high density plasmoids in axially symmetrical magnetic fields

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

Auxiliary ECR heating system for the gas dynamic trap

Physics aspects of a new system for electron cyclotron resonance heating (ECRH) at the magnetic mirror device Gas Dynamic Trap (GDT, Budker Institute, Novosibirsk) are discussed. This system based on two 400 kW / 54.5 GHz gyrotrons is aimed at increasing the electron temperature up to the range 250…350 eV for improved confinement. The key issue of the GDT conditions is that conventional ECRH geometries are not accessible. The proposed solution is based on a peculiar effect of radiation trapping in inhomogeneous magnetized plasma. Under specific conditions oblique launch of gyrotron radiation results in right-hand-polarized electromagnetic waves propagating with high n|| in the vicinity of the cyclotron resonance, what provides effective single-pass absorption of the injected microwave power.Обсуждаются физические аспекты и возможные параметры новой системы дополнительного ЭЦР-нагрева для газодинамической магнитной ловушки ГДЛ (ИЯФ, Новосибирск). При использовании излучения двух 400 кВт / 54.5 ГГц гиротронов можно ожидать повышения температуры электронов до 250…350 эВ и улучшения времени удержания ионов. Трудности, связанные с невозможностью использования традиционных схем ЭЦР-нагрева в геометрии ГДЛ, предлагается преодолеть за счет эффекта захвата излучения, вводимого из вакуума в виде необыкновенной волны под определенным углом, в трехмерно-неоднородной магнитоактивной плазме.Обговорюються фізичні аспекти і можливі параметри нової системи додаткового ЕЦР-нагріву для газодинамічної магнітної пастки ГДП (ІЯФ, Новосибірськ). При використанні випромінювання двох 400 кВт/54.5 ГГц гіротронів можна чекати підвищення температури електронів до 250…350 еВ і поліпшення часу утримання іонів. Труднощі, пов'язані з неможливістю використання традиційних схем ЕЦР-нагрівання в геометрії ГДП, пропонується подолати за рахунок ефекту захоплення випромінювання, що вводиться з вакууму у вигляді незвичайною хвилі під певним кутом, в тривимірно-неоднорідній магнітоактивній плазмі

23rd IAEA Fusion Energy Conference: summary of sessions EX/C and ICC

An overview is given of recent experimental results in the areas of innovative confinement concepts, operational scenarios and confinement experiments as presented at the 2010 IAEA Fusion Energy Conference. Important new findings are presented from fusion devices worldwide, with a strong focus towards the scientific and technical issues associated with ITER and W7-X devices, presently under construction