799 research outputs found

    Microwave Schottky diagnostic systems for the Fermilab Tevatron, Recycler, and CERN LHC

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    A means for non-invasive measurement of transverse and longitudinal characteristics of bunched beams in synchrotrons has been developed based on high sensitivity slotted waveguide pickups. The pickups allow for bandwidths exceeding hundreds of MHz while maintaining good beam sensitivity characteristics. Wide bandwidth is essential to allow bunch-by-bunch measurements by means of a fast gate. The Schottky detector system is installed and successfully commissioned in the Fermilab Tevatron, Recycler and CERN LHC synchrotrons. Measurement capabilities include tune, chromaticity, and momentum spread of single or multiple beam bunches in any combination. With appropriate calibrations, emittance can also be measured by integrating the area under the incoherent tune sidebands

    Scanning Electron Microscopy Application in Clinical Research

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    Our personal experience on the application of scanning electron microscopy in cardiology, gastroenterology and ophthalmology is reviewed. SEM has not yet significantly contributed to myocardium pathology. However, in the near future, SEM could be a reliable technique to complete the information available from other sources. As to atherosclerosis, SEM allowed us to improve our knowledge of the early stages of the disease; some pathological features, not always detected by conventional morphological examinations, can be documented. An important contribution to gastrointestinal pathology was made by SEM investigations both in the staging of some important diseases (i.e., coeliac disease, peptic ulcer, Crohn\u27s disease, ulcerative colitis) and in the follow-up of mucosal changes during therapy. In the ophthalmological field,SEM provided three-dimensional new information to clinicians, who are familiar with the biomicroscopic images. Our experience in hematology is still limited. However, in the lost few years SEM joined to immunocytochemistry allowed us to characterize cell populations in several blood diseases. Some procedures of particular interest in the management of human bioptic specimens are stressed in order to get to a complete correlative microscopy. We conclude that continuous and simultaneous correlations have to be carried out between SEM and other methods and instruments available for morphological investigation

    Performance Enhancement in CZTS Solar Cells by SCAPS-1D Software

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    This is the abstract, usually it does not have references. Usually the reader will read this part first to know what this paper is about and decide upon it to continue reading or not. The font of main text is 10 Times New Roman with single line spacing of 6 pt after and 0 pt before. The titles of sections are font 12, bold and they have single line spacing of 6pt before, 12 pt after, subsections are font 12, Italic and they have single line spacing of 6pt before, 12 pt after. Both upper line and lower line enclosing this part is paper-specific and changes according to the paper, usually it is very similar to the journal header background color, abstract contents are Times New Roman size 10, no line spacing

    Beam Voltage Effects in the Study of Embedded Biological Materials by Secondary Electron Detectors

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    Thin and semithin sections were extensively examined by the secondary electron (SE) detector in a conventional scanning electron microscope (SEM), and in a transmission electron microscope with a scanning attachment (STEM). Various para-meters, in particular the beam voltage, were shown to affect the final SE image (SEI). As for SEM observation, a surface contrast was imaged at low primary electron (PE) voltages (0.6-2 kV), whereas a subsurface contrast predominated at higher energies (15-30 kV). In STEM, significant differences were not detected by varying the PE in the 20-100 kV range. Surface and subsurface in-formation was simultaneously imaged even though the SEI were better resolved at the highest energy

    Progress with PXIE MEBT Chopper

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    A capability to provide a large variety of bunch patterns is crucial for the concept of the Project X serving MW-range beam to several experiments simultaneously. This capability will be realized by the Medium Energy Beam Transport's (MEBT) chopping system that will divert 80% of all bunches of the initially 5mA, 2.1 MeV CW 162.5 MHz beam to an absorber according to a pre-programmed bunch-by-bunch selection. Being considered one of the most challenging components, the chopping system will be tested at the Project X Injector Experiment (PXIE) facility that will be built at Fermilab as a prototype of the Project X front end. The bunch deflection will be made by two identical sets of travelling-wave kickers working in sync. Currently, two versions of the kickers are being investigated: a helical 200 Ohm structure with a switching-type 500 V driver and a planar 50 Ohm structure with a linear 250 V amplifier. This paper will describe the chopping system scheme and functional specifications for the kickers, present results of electromagnetic measurements of the models, discuss possible driver schemes, and show a conceptual mechanical design.Comment: 3 pp. 3rd International Particle Accelerator Conference (IPAC 2012) 20-25 May 2012. New Orleans, Louisian

    Status and specifications of a Project X front-end accelerator test facility at Fermilab

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    This paper describes the construction and operational status of an accelerator test facility for Project X. The purpose of this facility is for Project X component development activities that benefit from beam tests and any development activities that require 325 MHz or 650 MHz RF power. It presently includes an H- beam line, a 325 MHz superconducting cavity test facility, a 325 MHz (pulsed) RF power source, and a 650 MHz (CW) RF power source. The paper also discusses some specific Project X components that will be tested in the facility.Comment: 3 pp. Particle Accelerator, 24th Conference (PAC'11) 2011. 28 Mar - 1 Apr 2011. New York, US

    Conditions currently associated with erythema nodosum in Swiss children

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    A review was made of the 36 paediatric patients in whom the diagnosis of erythema nodosum had been established between 1977 and 1996 at the Department of Paediatrics, University of Bern, Switzerland. Infectious diseases were associated with erythema nodosum in 20 (including 10 streptococcal infections) and non-infectious inflammatory diseases in 8 patients. None of the 36 patients had tuberculosis or had been exposed to sulphonamides, phenytoin or hormonal contraceptives. There were eight patients in whom either the associated disease was not diagnosed, or there was no other disease. Conclusion Most cases of erythema nodosum are nowadays caused by non-mycobacterial infectious diseases or by non-infectious inflammatory disease
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