433 research outputs found

    CLIC RF High Power Production Testing Program

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    The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and generate RF power for the main linac accelerating structure. The demands on the high power production (~ 150 MW) and the needs to transport the 100 A drive beam for about 1 km without losses, makes the PETS design rather unique and the operation very challenging. In the coming year, an intense PETS testing program will be implemented. The target is to demonstrate the full performance of the PETS operation. The testing program overview and test results available to date are presented

    A Multi-Moded RF Delay Line Distribution System for the Next Linear Collider

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    The Delay Line Distribution System (DLDS) is an alternative to conventional pulse compression, which enhances the peak power of rf sources while matching the long pulse of those sources to the shorter filling time of accelerator structures. We present an implementation of this scheme that combines pairs of parallel delay lines of the system into single lines. The power of several sources is combined into a single waveguide delay line using a multi-mode launcher. The output mode of the launcher is determined by the phase coding of the input signals. The combined power is extracted from the delay line using mode-selective extractors, each of which extracts a single mode. Hence, the phase coding of the sources controls the output port of the combined power. The power is then fed to the local accelerator structures. We present a detailed design of such a system, including several implementation methods for the launchers, extractors, and ancillary high power rf components. The system is designed so that it can handle the 600 MW peak power required by the NLC design while maintaining high efficiency.Comment: 25 pages, 11 figure

    An Overview of Challenges on Smallholder Agroforestry Farms in Jigawa State, Northern Nigeria

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    Under the threat from a cocktail of climate change, environmental and soil, degradation and present economic meltdown in the country and world over, the practice of agroforestry come under a myriad of challenges. This study looks at Jigawa state, which has an agrarian based economy. With an estimate of 0.8ha being the average size of farmlands in the state, this study attempts to outline the pressing challenges facing these smallholder farms. A multistage sampling was employed for the study. Using division of the state into 3 zones which include; Jigawa southwest, Jigawa northwest, Jigawa northeast and.  Out of each zone, 3LGA were selected out of which 50 respondents were purposively targeted from each community providing the study with sampling frame of 450 respondents. The analysis proceeded by using mean, percentages and use of table and figures. The results show that tenure insecurity, herder problems as challenges to the farmers. Laxity on part of the institutions adds to the list. The study recommends the revitalization of relevant bodies charged with maintenance and dissemination of information and incentives on use of modern agroforestry to ensure its sustainability. Keywords: Agroforestry, Smallholder, Tenure insecurity, Herder Proble

    An Assessment of Suitability of Climate for Tourism in Northwestern Nigeria

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    Tourism is vital to national economies and income of its individual citizens. This paper investigated the suitability of climate for tourism in Northwestern Nigeria using the tourism climate index developed by Mieczkowski (1985). Parameters used for calculating the index include monthly average maximum daily temperature, rainfall, mean daily relative humidity, minimum relative humidity, total wind speed and sunshine hours. The stations used for the calculation of TC index include Kaduna, Kano, Katsina and Sokoto. The result is presented in the form of charts using excel, while GIS is used for zoning of tourism climatic conditions in different months. Result shows that the study area is suitable for tourism throughout the year, as all the TCI scores ranges from 94 to 41 (‘ideal’ to ‘marginal') except for Kano in the month of June which has a TCI score of 39 (‘unfavorable’). The months of January, February, November and December are the best months for tourism as they recorded higher TCI values of 73 to 94 (‘very good’ to ‘ideal’). It is therefore concluded that the best time for tourist to visit Northwestern Nigeria is during the months of January, February, November and December. Keywords: Climate, Tourism, Tourism Climate Index, Nigeri

    Active RF Pulse Compression Using Electrically Controlled Semiconductor Switches

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    In this paper, we present the recent results of our research on the ultra-high power fast silicon RF switch and its application on active X-Band RF pulse compression systems. This switch is composed of a group of PIN diodes on a high purity silicon wafer and has achieved a switching time of 300ns. The wafer is inserted into a cylindrical waveguide operating in the TE01 mode. Switching is performed by injecting carriers into the bulk silicon through a high current pulse. The RF energy is stored in a room-temperature, high-Q 375 ns delay line; it is then extracted out of the line in a short time using the switch. The pulse compression system has achieved a gain of 8, which is the ratio between output and input power

    Knowledge-Based System for the Diagnosis of Flatulence

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    Diagnosing flatulence involves a thorough assessment of an individual's symptoms, medical history, and, if necessary, the use of diagnostic tests. Healthcare providers gather information about the patient's medical background and conduct a physical examination to identify any signs of gastrointestinal issues. Dietary habits are evaluated, and potential triggers are identified through an elimination diet. Diagnostic tests such as breath tests, stool analysis, or imaging studies may be performed to further investigate the underlying causes of excessive flatulence. Accurate diagnosis is crucial for effective management and treatment of flatulence, enabling individuals to gain control over their symptoms and address any underlying conditions

    Molybdenum sputtering film characterization for high gradient accelerating structures

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    Technological advancements are strongly required to fulfill the demands of new accelerator devices with the highest accelerating gradients and operation reliability for the future colliders. To this purpose an extensive R&D regarding molybdenum coatings on copper is in progress. In this contribution we describe chemical composition, deposition quality and resistivity properties of different molybdenum coatings obtained via sputtering. The deposited films are thick metallic disorder layers with different resistivity values above and below the molibdenum dioxide reference value. Chemical and electrical properties of these sputtered coatings have been characterized by Rutherford backscattering, XANES and photoemission spectroscopy. We will also present a three cells standing wave section coated by a molybdenum layer ∼\sim 500 nm thick designed to improve the performance of X-Band accelerating systems.Comment: manuscript has been submitted and accepted by Chinese Physics C (2012
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