Design and high-power test of 800-kW UHF klystron for CEPC

To reduce the energy demand and operation cost for circular electron positron collider(CEPC), the high efficiency klystrons are being developed at Institute of High Energy Physics, Chinese Academy of Sciences. A 800-k W continuous wave(CW) klystron operating at frequency of 650-MHz has been designed. The results of beam–wave interaction simulation with several different codes are presented. The efficiency is optimized to be 65% with a second harmonic cavity in three-dimensional(3D) particle-in-cell code CST. The effect of cavity frequency error and mismatch load on efficiency of klystron have been investigated. The design and cold test of reentrant cavities are described, which meet the requirements of RF section design. So far, the manufacturing and high-power test of the first klystron prototype have been completed.When the gun operated at DC voltage of 80 k V and current of 15.4 A, the klystron peak power reached 804 k W with output efficiency of about 65.3% at 40% duty cycle. The 1-d B bandwidth is ±0.8 MHZ. Due to the crack of ceramic window, the CW power achieved about 700 kW. The high-power test results are in good agreement with 3D simulation.

Electron Beam Guns for High Energy Electron Accelerators: An Overview

Thermionic electron beam is a fundamental part of all types of linear accelerators around the world in the field of Experimental High Energy Physics. Thermionic beam is very inexpensive and simple to produce. In this work, we give an overview of generation, design and applications of the electron beam with particular reference to e-beam generation at high energy linear accelerators. Experimental data are presented in tabular form for ready reference. We also make an evaluation of these high energy sources with our in-house designed e-beam gun. Finally, a comparison has been presented in terms of characteristic parameters of all these high performance sources.

Magnetically treated water irrigation effect on turnip seed germination,seedling growth and enzymatic activities

Pre-sowing magnetic field seed treatment effects on biological characteristics of vegetables and crops have been studied well.However,studies reporting irrigation with magnetically treated water are scanty.Therefore,the effect of irrigation with magnetically treated water on turnip seed germination,seedling growth and enzymatic activities was evaluated.The tap water was treated at 211 mT for 30,45 and 60 min and used for irrigation of turnip seed and seedlings.Uniform and healthy turnip seed was sown under randomized complete block design(RCBD).The germination,emergence rate index,vigor index I and vigor index II increased up to 28.33%,11.54%,57.59%and 32.26%,respectively.The growth parameters such as seedling lengths,fresh&dry weights,chlorophyll content were also enhanced in response of irrigation with magnetically treated water.The seedlings irrigated with magnetically treated water showed 28.92%,11.36%and 14.76%higher protein content,alpha amylase and protease activities,respectively vs control.Results revealed that irrigation with magnetically treated water has potential to improve turnip germination,seedling growth and enzymatic activities and this study is also extendable to other vegetables and crops for the improvement of germination and growth.

Total phenolic,chromium contents and antioxidant activity of raw and processed sugars

Processing improves the visual quality of food;however,the ingredient and nutritional values may alter.In present study,the sugar samples(refined,raw,gur(Jaggery/jaggeree)and molasses)were collected from 20 different agro-climatic regions of Pakistan and analyzed for the chromium concentration,total phenolic and antioxidant activity,in order to evaluate the processing effect.The concentration of Cr was determined by digestion method using atomic absorption spectrophotometer,while antioxidant activity was determined by DPPH(1,1-diphenyl-2-picrylhydrazyl)and reducing power.It was observed that chromium content in Jaggery was 74%higher than raw sugar,while molasses showed 21.27%higher concentration versus jaggery.The total phenolic contents were found considerably higher in molasses(3751 lg GAE/g)followed by Jaggery(3285 lg GAE/g),raw sugar(27.75 lg GAE/g)and refined sugar(23.81 lg GAE/g).The DPPH scavenging activity and reducing power was also found dependent to sugar type.Form results,it can be concluded that processing significantly affected the chromium contents,total phenolics and antioxidant activity.

Effect of gravistimulation on amino acid profile of pea,rice,corn,wheat during early growth stages

The amino acids are one of the major cellular components of plants,which are involved in different metabolic pathways.In present study,effect of artificial gravistimulation on amino acid profiles of pea,rice,corn,wheat during early growth stages was investigated.One-axis clinostat was used for gravistimulation application,which was applied at embryonic stage.Amino acid profile was measured in 10-days old seedlings of pea,rice,corn and wheat cultivars.The effect of clinostat rotation was also evaluated under salt stress and MS medium supplement.Germinated pea,rice,corn and wheat seedlings were grown under the gravity condition for specific time interval.Corn and wheat seeds showed slowgermination as compared to pea and rice cultivars.The rate of amino acid formation under gravity condition was significantly higher than control(un-treated seedling).The variation in amino acid profile of pea,rice,corn and wheat cultivars vary deferentially.Results revealed that gravistimulation applied through clinostat has positive effect on amino acid profile in plant tissue and future studies should be focused on growth,biochemical,physiological at lateral stages of growth.

Production and characterization of organic manure from liquorice residues

In present investigation,organic manure was produced and characterized from liquorice residues using activated Effective Microoganism(AEM).The liquorice waste residues were fermented for the period of 6 months in the presence of activated AEM at the rate of 2.5%and 5%of total fermented mixture.Nitrogen(62.5 g)was used per 10 kg of liquorice and moister was maintained at 55–60%during fermentation.The AEM manure production efficiency was evaluated on the basis of pH,C/N ratio,electrical conductivity(EC)and mineral contents.The final pH of organic manure was 6.2,C/N ratio reduced from 13.5 to 6.5,EC and the mineral contents were increased of composted liquorice.Results revealed that the AEM are effective to produce organic manure from agricultural waste matter since the organic manure physico-chemical properties were within the permissible limit and AEM could be used for the production of compost liquorice.Moreover,this technique can also be extended to other agricultural waste materials for the production of organic manure.