Investigation of possible csr induced energy spread effects with the A0 photoinjector bunch compressor

The bunch compressor of the A0 Photoinjector at Fermilab was removed this past spring to install a transverse to longitudinal emittance exchange experiment. Prior to its removal questions arose about the possibility of observing the effects of Coherent Synchrotron Radiation on the compressed beam. The energy spread of the beam with and without compression was measured to observe any changes. Various beam charges were used to look for square law effects associated with CSR. No direct observation of CSR in the compressor was attempted because the design of the vacuum chamber did not allow it. In this paper we report the results of these experiments and comparison with simulations using ASTRA and CSRTrack. The results are also compared with analytical approximations

Observations of underdense plasma lens focusing of relativistic electron beams

Focusing of a 15 MeV, 19 nC electron bunch by an underdense plasma lens operated just beyond the threshold of the underdense condition has been demonstrated in experiments at the Fermilab NICADD Photoinjector Laboratory (FNPL). The strong 1.9 cm focal-length plasma-lens focused both transverse directions simultaneously and reduced the minimum area of the beam spot by a factor of 23. Analysis of the beam-envelope evolution observed near the beam waist shows that the spherical aberrations of this underdense lens are lower than those of an overdense plasma lens, as predicted by theory. Correlations between the beam charge and the properties of the beam focus corroborate this conclusion

UCLA/FNPL Underdense Plasma Lens Experiment: Results and Analysis

Focusing of a 15 MeV, 16 nC electron bunch by a gaussian underdense plasma lens operated just beyond the threshold of the underdense condition has been demonstrated. The strong 1.9 cm focal length plasma lens focused both transverse directions simultaneously and reduced the minimum area of the beam spot by a factor of 23. Analysis of the beam envelope evolution observed near the beam waist shows that the spherical aberrations of this underdense lens are lower than those of an overdense plasma lens, as predicted by theory. Time resolved measurements of the focused electron bunch are also reported and compared to simulations

Results from the UCLA/FNPL underdense plasma lens experiment

A gaussian underdense plasma lens with peak density 5 x 10{sup 12} cm{sup -3} and a full width half maximum (FWHM) length of 2.2 cm has been used to focus a relativistic electron beam. This plasma lens is equivalent in strength to a quadrupole magnet with a 150 T/m field gradient. The lens focused a 15 MeV, 16 nC electron beam with initial dimensions {sigma}{sub x,y} {approx} 650 {micro}m and {sigma}{sub z} {approx} 6.5 mm onto an optical transition radiation (OTR) screen {approx}2 cm downstream of the lens. The average transverse area of the plasma focused electron beam was typically demagnified by a factor of 23. The evolution of the beam envelope in the area near the beam waist was measured for both round beams and asymmetric beams with x:y aspect ratios as large as 1:5. The light from the OTR screen in the round beam case was also imaged into a streak camera in order to directly measure the correlation between z and {sigma}{sub r} within the beam

Механизация полевой сушки трав: пути совершенствования

High-quality grass feeds (hay, haylage, silage) decrease cost price, improve consumer properties and increase competitiveness of cattle products significantly being the main component of agricultural export for the Republic of Belarus. An important issue of grass feed procurement is acceleration of mowed grass drying process. Reduction of drying time or drying process acceleration has a positive effect on feed quality. To achieve this goal, technique of laying the mowed grass on stubble, in rolls or spreading, turning and conditioning is applied. Based on practical experience of application and analysis, the relevance of repeated rolling (reconditioning) of mowed grasses in rolls is substantiated. Design and workflow of new device for such grass rolling has been developed. Its working unit is designed as a sawn-deck or roller flatting apparatus. The kinematic parameters of the upper and lower rollers have been determined experimentally: the rollers rotation ratio should make 1.01 m ωв / ωн m 1.03. Field tests of the device with legumes helped to determined that it accelerates drying by 15–20%, reduces protein loss by 10–15% compared to drying with no treatment. The presented research materials present the development of the theory of grass feeds procurement mechanization. Use of the materials in practice will improve the quality of grass feeds by accelerating the mowed grass drying process.Качественные травяные корма (сено, сенаж, силос) существенно снижают себестоимость, улучшают потребительские свойства и повышают конкурентоспособность продукции крупного рогатого скота, являющейся для Республики Беларусь основной составляющей аграрного экспорта. Важным элементом процесса заготовки травяных кормов является ускорение сушки скошенных трав. Сокращение времени сушки или ее ускорение положительно влияет на их качество. Для достижения этой цели применяют укладку скошенных трав на стерню, в валки или растил, ворошение и кондеционирование. На основе их практического опыта применения и анализа обоснована актуальность повторного плющения (рекондеционирование) скошенных трав в валках. Разработана конструкция и рабочий процесс нового устройства для такого плющения трав. Его рабочий орган выполнен как бильно-дековый или вальцевый плющильный аппарат. Экспериментально установлены кинематические параметры работы верхнего и нижнего вальцов: соотношение их вращения должно быть 1,01 m ωв / ωн m 1,03. Полевыми испытаниями устройства на бобовых травах определено, что его применение способствует ускорению сушки на 15–20 %, уменьшает потери протеина на 10–15 % по сравнению с сушкой без обработки. Представленные материалы исследования являются развитием теории механизации заготовки травяных кормов. Их использование на практике будет способствовать повышению качества травяных кормов благодаря ускорению сушки скошенной травы

Cytotoxicity and ion release of alloy nanoparticles

It is well-known that nanoparticles could cause toxic effects in cells. Alloy nanoparticles with yet unknown health risk may be released from cardiovascular implants made of Nickel–Titanium or Cobalt–Chromium due to abrasion or production failure. We show the bio-response of human primary endothelial and smooth muscle cells exposed to different concentrations of metal and alloy nanoparticles. Nanoparticles having primary particle sizes in the range of 5–250 nm were generated using laser ablation in three different solutions avoiding artificial chemical additives, and giving access to formulations containing nanoparticles only stabilized by biological ligands. Endothelial cells are found to be more sensitive to nanoparticle exposure than smooth muscle cells. Cobalt and Nickel nanoparticles caused the highest cytotoxicity. In contrast, Titanium, Nickel–Iron, and Nickel–Titanium nanoparticles had almost no influence on cells below a nanoparticle concentration of 10 μM. Nanoparticles in cysteine dissolved almost completely, whereas less ions are released when nanoparticles were stabilized in water or citrate solution. Nanoparticles stabilized by cysteine caused less inhibitory effects on cells suggesting cysteine to form metal complexes with bioactive ions in media