The modified 200 keV pulsed electron beam source for the VEPP-5 injection complex

The modified pulsed electron beam source on voltage 200 kV and current 10 A with half-height pulse duration 2.5 ns and repetition rate 50 Hz is described. The source gun has been performed on the base of impregnated cathode with 20 mm diameter. The cathode pulse voltage is formed by storage capacitance discharge through IGBT switch and pulse transformer. The gun control unit located at the high voltage potential produces cathode heat voltage and control grid voltage. The source test results are presented.Описан модифицированный источник электронного пучка на напряжение 200 кВ, импульсный ток до 10 А, длительность импульса на полувысоте 2,5 нс при частоте следования 50 Гц. Источник выполнен на базе импрегнированного катода диаметром 20 мм. Импульсное напряжение на катоде пушки формируется путем разряда накопительной емкости через IGBT-ключ и импульсный трансформатор. Блок управления пушкой, расположенный под высоким потенциалом, формирует напряжение накала и сеточное напряжение. Приведены результаты испытаний источника.Описано модифіковане джерело електронного пучка на напругу 200 кВ, імпульсний струм до 10 А, тривалість імпульсу на напіввисоті 2,5 нс при частоті проходження 50 Гц. Джерело виконане на базі імпрегнуваного катоду діаметром 20 мм. Імпульсна напруга на катоді гармати формується шляхом розряду накопичувальної ємності через ІGBT-ключ і імпульсний трансформатор. Блок керування гарматою, розташований під високим потенціалом, формує напругу накалу і сіткову напругу. Наведено результати випробувань джерела

Electron accelerator for energy up to 5.0 MeV and beam power up to 50 kW with Х-ray converter

The paper describes the industrial electron accelerator ILU-10 for electron energy up to 5 MeV and beam power up to 50 kW specially designed for use in industrial applications. The ILU-10 accelerator generates the vertical electron beam. The beam line turns the beam through an angle of 90° and transports the beam to the vertically posed Xray converter to generate the horizontal beam of X-rays.Приводиться опис прискорювача електронів ІЛУ-10 на енергію 5 МеВ потужністю 50 кВт, спеціально розробленого для таких комплексів. Для спрощення конструкції конвеєрної системи подачі оброблюваної продукції в зону опромінення використовується випускний пристрій з поворотом пучка на 90 градусів інаступною конвертацією електронного пучка в гамма-випромінювання на вертикально розташованій мішені.Приводится описание ускорителя электронов ИЛУ-10 на энергию 5 МэВ мощностью 50 кВт, специально разработанного для таких комплексов. Для упрощения конструкции конвейерной системы подачи обрабатываемой продукции в зону облучения используется выпускное устройство с поворотом пучка на 90 градусов и последующей конвертацией электронного пучка в гамма-излучение на вертикально расположенной мишени

Work status of 5 MeV 300 kW electron accelerator

Design work has been completed for the accelerating structure of high-power electron accelerator with 5 MeV, 300 kW, 176 MHz parameters. The structure is being produced in BINP workshop. The paper presents the design of the accelerating structure which consists of a chain of coaxial cavities, and block diagram of experimental workbench. Structure of the main accelerator blocks and their degree of fabrication are viewed.Закончены проектные работы по ускоряющей структуре мощного электронного ускорителя 5 МэВ, 300 кВт, 176 МГц и ведется ее изготовление в опытном производстве Института. Дается описание конструкции ускоряющей структуры, состоящей из цепочки связанных коаксиальных резонаторов. Приводится блок-схема испытательного стенда, рассматривается устройство отдельных узлов ускорителя и состояние их готовности.Закінчено проектні роботи із прискорювальної структури потужного електронного прискорювача 5 МеВ, 300 кВт, 176 МГц і ведеться її виготовлення в дослідному виробництві інституту. Дається опис конструкції прискорювальної структури, що складається з ланцюжка зв'язаних коаксіальних резонаторів. Приводиться блок-схема іспитового стенда, розглядається будова окремих вузлів прискорювача і стан їх готовності

Structure of mandibles in relation to trophic niche differentiation in a tropical millipede community

Isotopic composition of nitrogen in 19 species of Diplopoda from a tropical monsoon forest (Cat Tien National Park, southern Vietnam) which supports one of the most diverse millipede faunules globally (no less than 36 species from 17 families and 11 orders) forms a wide continuum of δ15N values ranging from -2.4 to +6.8‰. This suggests a trophic niche differentiation among species. Variation in mouthpart structure could presumably reflect the different foods consumed by species representing at least higher taxa (families and orders). The fine structure of the mandibles in ten sympatric, mostly even syntopic species of Diplopoda does differ considerably between the higher taxa, but neither at the generic nor species level. Neither clear-cut trends in nor evident morphological patterns of, nor significant correlations between the structure of mandibles in Diplopoda species that have different isotopic compositions of nitrogen and presumably exploit different food resources, have been revealed

EFFECT OF MACROPLASTIC ON SOIL INVERTEBRATES: A CASE STUDY USING MORPHOLOGICAL AND MOLECULAR APPROACHES

Soil contamination by plastic is a global problem. Most experimental studies focus on microplastics, but large fragments, such as a variety of packaging and plastic bags, make up a significant component of plastic pollution. The effects of large fragments of household plastic debris on soil invertebrate communities are largely unexplored. The use of metabarcoding can greatly simplify the assessment of the taxonomic composition of soil invertebrates as well as their symbionts and parasites. However, the method is still underdeveloped and requires verification by classical approaches. We used metabarcoding and the traditional approach based on the morphological identification of invertebrates in assessing the effect of macroplastics on soil animal communities. Fragments of transparent or black polyethylene film measuring 40 × 40 cm were fixed on the soil surface in four forest ecosystems. After 9 months, the total abundance of mesofauna in general and individual groups of invertebrates (Collembola, Mesostigmata) was significantly reduced in the soil under the film compared to the control plots. The presence of the film did not affect the abundance of macrofauna, but in some biotopes the abundance of Isopoda, Hemiptera and Chilopoda increased and the number of Coleoptera and Diptera larvae decreased under the plastic film. The applied modification of metabarcoding revealed a significantly lower diversity of invertebrates (66 families, 105 genera) compared to the morphological method of identification (95 families, 127 genera). Wolbachia and Rickettsia, typical endosymbionts of invertebrates, but not other common parasites, were noted. In contrast to the morphological method of determination, metabarcoding revealed no significant differences in the taxonomic composition of invertebrates in the soil under the film and in the control soil. However, the significant correlation between the results of morphological identification and metabarcoding confirms the ability of metabarcoding to detect even small changes in the taxonomic composition of soil invertebrate communities

Interactions of juvenile Lumbricus terrestris with adults and their burrow systems in a two-dimensional microcosm

The objective of this work was to evaluate interactions of Lumbricus terrestris juveniles with adults and with inherited burrow systems. An experiment was set up using a two dimensional Evans' boxes microcosm. Adult L. terrestris were added to 16 boxes (one individual per box) and kept in darkness at 17ºC along with eight unoccupied boxes for two months. The adult L. terrestris were removed from eight randomly selected boxes, and L. terrestris juveniles were added (one juvenile per box), composing three treatments with eight replicates: 1, with an adult in an inherited burrow (ABJ); 2, alone in an inherited burrow (BJ); and 3, alone in a previously uninhabited box (J). The proportion of juveniles occupying adult burrows observed was significantly different in treatments ABJ (48%) and BJ (75%). The mean mass of juveniles at experimental termination differed significantly among treatments and was greater in treatment J (4.04±0.39 g) in comparison to the BJ (3.09±0.93 g) and ABJ treatments (2.13±0.64 g). Results suggest a negative influence of both the presence of an adult and its burrow system on juvenile growth. Intraspecific competition partially explained this, but further investigation is required to examine how an inherited environment (i.e. burrow) could negatively affect the growth of juveniles.<br>O objetivo deste trabalho foi avaliar as interações de juvenis de Lumbricus terrestris com indivíduos adultos e com sistemas de galerias herdados. O experimento foi realizado usando microcosmos bidimensionais de Evans como unidades experimentais. Adultos de L. terrestris foram colocados em 16 unidades experimentais (um indivíduo por unidade) e mantidos no escuro a 17ºC juntamente com oito unidades experimentais inabitadas, por dois meses. Os adultos foram removidos de oito unidades selecionadas aleatoriamente e juvenis foram adicionados a todas as unidades experimentais (um indivíduo por unidade), em três tratamentos, com oito repetições: 1, com um adulto em um sistema de galerias herdado (ABJ); 2, sozinho em um sistema de galerias herdado (BJ); e 3, sozinho em uma unidade experimental inabitada (J). A proporção de juvenis observados ocupando as galerias feitas pelos adultos foi significativamente diferente nos tratamentos ABJ (48%) e BJ (75%). A biomassa média dos juvenis ao final do experimento diferiu significativamente entre os tratamentos e foi maior no tratamento J (4.04±0.39 g) em comparação com os tratamentos BJ (3.09±0.93 g) e ABJ (2.13±0.64 g). Os resultados sugerem uma influência negativa tanto da presença de um adulto quanto do seu sistema de galerias no crescimento dos juvenis. A competição intraespecífica explica parcialmente este fenômeno, porém novas investigações devem ser feitas para examinar como um ambiente herdado (galerias) pode afetar negativamente o crescimento de juvenis