High-current ion linac calculation

The research on multibeam ion accelerators has been carried. Full analysis of the oscillating system on example of a HCIL cell containing a pair of conducting rings (CR) with drift tubes (DT) and a central drift channel was carried out. High-current electronic beam is used as an electromagnetic power supply, which not exclude an external power source. Interaction factor of an electronic beam with a field of about 100%, kiloampere currents and megawatt power levels allows to produce a compact electron-beam pumping system with drift tubes shorter then wavelength

Shock-wave dynamics under expansion of the spark channel in gas

The process of formation of shock waves arising at a spark discharge is considered. According to analysis of experimental statistics the results of the various authors about dynamics of development of the spark channel are exposed to a doubt. The definition of a concept of time of formation of a shock wave is offered and its quantitative evaluation is carried out. It has allowed to distinguish the process of formation from the process of development of a shock wave, and also to explain the fact of formation of several shock waves at a spark discharge. The offered work can be put in a basis of a technique for evaluation of the intensity of a shock wave formed at a spark discharge

Study on radiation resistence of permanent NdFeB-base magnets under continuons radiation conditions

The development of present-day technologies and materials for creating permanent magnets (in particular, at NSC KIPT), and increasing demands for devices in which these materials are used for physics and technology of intense (10 to 40 MeV) electron beam forming have motivated the comprehensive study on characteristics of these materials under extreme conditions of their use

Analysis of the process of raising the temperature in the spark channel at a discharge in gas

Analysis of the process of raising the temperature in the spark channel at a discharge in gas is performed. The quantitative evaluation was made in main for the air. The effect of steadying a thermodynamic equilibrium in gas, as well as the influence of power discharge parameters on the process of temperature increasing was analyzed. The quantitative evaluation of time parameters of the processes of rotary, oscillatory relaxation, dissociation and ionization has allowed to reveal the influence of each of them on temperature increasing in the spark channel. The problems arising in the course of practical realization of a spark discharge which influence on the process of temperature raising are detected, and the ways for their solution are determined. The results obtained can be put in a basis of developing the methods to design devices for intensive increase of temperatures in gas media using the electrical discharge, as well as for analysis of a dependence of shock wave intensity on dynamic parameters of the electrical discharge

Cumulation and acceleration of ions by TW femtosecond laser pulse

A new method of ion cumulation and acceleration at three-dimensional compression of plasma in the ”light trap” created in the focal region of the high-power femtosecond laser is theoretically studied. The ”light trap” is formed by delay in time of the central part of the laser pulse being focused. The cumulation degree and maximum energy of acceleration ions depending on values of the high-power femtosecond laser pulse have been investigated by numerical methods. Physical mechanisms of ion density and energy increase in the paraxial plasma zone have been discussed. The proposed method of ion cumulation and acceleration allows one to create compact bright sources of fast neutrons, nuclei for x-ray and gamma lasers, and also provides the unique possibilities of nuclear reaction initiation and isotope production.Теоретично досліджен новий метод прискорення та кумуляції при трьохвимірному стисненні плазми в “світової пастці”, що утворюється в фокальної області потужного фемптосекундного лазера. “Світлова пастка” формується шляхом затримки центральної частини лазерного імпульсу. Чисельними методами вивчені степінь кумуляції та максимальна енергія іонів в залежності от параметрів потужного лазерного імпульсу. Запропонований метод кумуляції та прискорення іонів дозволяє розробити компактні джерела швидких нейтронів середовища для рентгенівського то гамма-лазерів, а також дає унікальні можливості ініціювання ядерних реакцій і отримання ізотопів.Теоретически исследован новый метод ускорения и кумуляции ионов при трехмерном обжатии плазмы в “световой ловушке”, создаваемой в фокальной области мощного фемтосекундного лазера. “Световая ловушка ” формируется путем задержки во времени центральной части фокусируемого импульса. Численными методами изучены степень кумуляции и максимальная энергия ускоренных ионов в зависимости от параметров мощного лазерного импульса. Обсуждены физические механизмы увеличения плотности и энергии ионов в приосевой области плазмы. Предложенный метод кумуляции и ускорения ионов позволяет создать компактные яркие источники быстрых нейтронов, среды для рентгеновского и гамма-лазеров, а также создает уникальные возможности инициирования ядерных реакций и получения изотопов

Optimization of initial gal distribution in plasma focus discharges

L'influence de #Meloidogyne arenaria sur le flétrissement, causé par #Pseudomonas solanacearum (E.F. Smith), de deux cultivars de tomate dont un très sensible au flétrissement (Floradel) et l'autre plus résistant (Caraïbo), a été étudiée. Deux souches de bactéries ont été inoculées avec 0, 100, 1000 et 10000 larves de #Meloidogyne. Une des souches de #P. solanacearum était peu pathogène (MT4) et l'autre très pathogène (MT1). La sensibilité du cultivar Floradel envers MT4 n'est pas modifiée par la présence des nématodes ; par contre la résistance du cultivar Caraïbo varie en fonction de la quantité de #Meloidogyne$inoculée. Quand le cultivar Caraïbo est inoculé avec la souche très pathogène MT1, les symptômes apparaissent plus tôt et la progression de la maladie est accélérée par l'action des nématodes. En absence de bactérie, 10$. A l'inverse, #P. solanacearum n'a pas d'influence sur la croissance des parties aériennes et le développement des galles de #Meloidogyne sur les racines. (Résumé d'auteur

The magnetic field effect on electron beam generation in magnetron injection guns with secondary-emission cathodes

Magnetron guns with secondary-emission cathodes appear promising for the use as electron sources in high-power microwave devices [1, 2]. For stable beam generation, the magnetic field in the gun is calculated to be between 0.5 to 5 kG, depending on the cathode voltage amplitude and the gun dimensions. On the other hand, the beam transport in the resonance system of the microwave device also calls for rather high magnetic fields. The generation of these fields of significant extent to produce and transport the beam is a rather grave problem. It is generally solved by using water-cooled solenoids [3], that gives rise to considerable difficulties. In recent years, constant magnets have been used [3] to generate extended solenoidal magnetic fields. So, it was of interest to investigate both the generation of such fields and their effect on beam production and parameters in the magnetron gun