RF system of the race-track microtron – recuperator for high power free electron laser

A brief description of the RF system of 100 MeV race-track microtron-recuperator being built in Novosibirsk for the Free Electron Laser project at Siberian center of Photochemistry research is presented. The frequency of RF system is 180.4 MHz. The RF system consists of 2 parts: the RF system of 2 MeV injector and the RF system of microtron. The injector RF system includes 3 RF cavities - one buncher cavity and two accelerating cavities. RF cavities are driven by a 2.5 kW amplifier and two high power single-tube 130 kW RF amplifiers respectively. The RF system of microtron includes 16 RF cavities operating at a gap voltage of 850kV each. Two 4-tubes power amplifiers supply the RF power of 600 kW each to the cavities via distribution feeders. In the high power amplifier stages the tetrodes GU-101A are used. The control system controls the amplitude and phase of RF voltage in the cavities and provides signals for synchronization of the electron gun. The results of the operation of the injector RF system and status of large RF system for the microtron are discussed

First experimental results obtained using the highpower free electron laser at the siberian center for photochemical research

The first lasing near the wavelength of 140 µm was achieved in April 2003 using a high-power free electron laser (FEL) constructed at the Siberian Center for Photochemical Research. In this paper we briefly describe the design of the FEL driven by an accelerator–recuperator. Characteristics of the electron beam and terahertz laser radiation, obtained in the first experiments, are also presented in the paper.У Сибірському центрі фотохімічних досліджень навесні 2003 року отримана генерація випромінювання з довжиною хвилі 140 мкм на потужному лазері на вільних електронах (ЛВЕ). У роботі коротко описана конструкція ЛВЕ на базі прискорювача рекуператора і представлені результати вимірювання деяких параметрів електронного пучка і терагерцового випромінювання.В Сибирском центре фотохимических исследований весной 2003 года получена генерация излучения с длиной волны 140 мкм на мощном лазере на свободных электронах (ЛСЭ). В работе кратко описана конструкция ЛСЭ на базе ускорителя рекуператора и представлены результаты измерения некоторых параметров электронного пучка и терагерцового излучения

Response of wild Avena species to fungal infection of grain

Sixty-six accessions belonging to Avena species (A. atlantica, A. canariensis, A. clauda, A. damascena, A. hirtula, A. longiglumis, A. wiestii, A. agadiriana, A. barbata, A. vaviloviana, A. insularis, A. magna, A. murphyi, A. fatua, A. ludoviciana, A. occidentalis, A. sterilis, A. sativa, and A. byzantina) obtained from the N. I. Vavilov Institute of Plant Genetic Resources (VIR) were tested for the infection of grain by Alternaria and Cladosporium at the genus level and by a group of trichothecene-producing Fusarium fungi. Real-time PCR was performed to quantify fungal abundance and ELISA was performed for mycotoxin analysis in grain. The average amounts of all tested fungi in tetraploid Avena species were higher than those in diploid and hexaploid species. Low amounts of deoxynivalenol (DON) were detected in seven hexaploid genotypes (A. sterilis, A. byzantina, A. sativa, and A. fatua) and one diploid genotype (A. wiestii). The relationship between some morphological traits (1000-grain weight, percent of husk, trichome density, and plant height) of Avena species and grain infection by fungi and mycotoxins was investigated. Alternaria and Cladosporium fungi could not penetrate the husk. A highly negative correlation of the amounts of their DNA with the proportions of husk in grain as well as with trichome density was found. In contrast, a significant positive correlation between the amount of Fusarium DNA and these traits was found. A strong negative correlation between plant height and DNA of the analyzed fungi was found. The oats least infected by Alternaria, Cladosporium, and Fusarium fungi and containing low amounts of DON were accessions of the hexaploids A. byzantina, A. fatua, A. sativa, A. sterilis, and the diploid A. wiestii. Keywords: Avena species, Grain, Fungal DNA, Mycotoxi