Measurements of wake-induced electron beam deflection in a dechirper at the Linac Coherent Light Source

The RadiaBeam/SLAC dechirper, a structure consisting of pairs of flat, metallic, corrugated plates, %a corrugated structure in flat geometry, has been installed just upstream of the undulators in the Linac Coherent Light Source (LCLS). As a dechirper, with the beam passing between the plates on axis, longitudinal wakefields are induced that can remove unwanted energy chirp in the beam. However, with the beam passing off axis, strong transverse wakes are also induced. This mode of operation has already been used for the production of intense, multi-color photon beams using the Fresh-Slice technique, and is being used to develop a diagnostic for attosecond bunch length measurements. Here we measure, as function of offset, the strength of the transverse wakefields that are excited between the two plates, and also for the case of the beam passing near to a single plate. We compare with analytical formulas from the literature, and find good agreement. This report presents the first systematic measurements of the transverse wake strength in a dechirper, one that has been excited by a bunch with the short pulse duration and high energy found in an X-ray free electron laser.Comment: 8 pages, double column, 6 figure

Análisis de la situación económica y financiera de la empresa H.K. Distribuciones S.R.L. de la ciudad de Puno en los periodos 2014 – 2015

TesisEl trabajo de investigación que lleva por título: “Análisis de la Situación Económica y Financiera de la Empresa H.K. Distribuciones S.R.L. de la ciudad de Puno en los periodos 2014 – 2015”; Se ejecutó en la ciudad de Puno, de la región del mismo nombre y cuya población de estudio es la empresa mencionada; Esta investigación nos ha permitido analizar la información que contienen los estados financieros de esta empresa y que sirven para tomar decisiones gerenciales acertadas por parte de sus directivos; El objetivo de la investigación fue: Analizar y evaluar la influencia de la situación económica y financiera en las decisiones gerenciales de la empresa HK distribuciones S.R.L. de la ciudad de Puno en los periodos 2014 - 2015; La metodología aplicada para su desarrollo estuvo establecido a través de los métodos descriptivo y deductivo, los que nos permitieron establecer nuestras conclusiones de la investigación: Según el análisis del Estado de situación financiera de la Empresa “HK Distribuciones S.R.L.” podemos deducir que se muestra una desmejora en la gestión y resultados en el periodo 2015, mostrando un aumento en las Cuentas por cobrar comerciales a los clientes en un 1,304% y también un incremento de sus Cuentas por pagar comerciales de sus proveedores en un 158,028.00; Así mismo se muestra que la empresa cuenta con endeudamiento contraído de las entidades financieras que los viene amortizando periódicamente pero que generan gastos financieros; Respecto al capital de la empresa se mantiene constante y se ve una disminución significativa de las utilidades netas en el año 2015 en 10.15% respecto al ejercicio anterior. Según el Análisis del Estado de Resultados se observa que las ventas de la empresa disminuyeron significativamente en el año 2015 en S/. 166,237.00 que representa el 6% respecto al periodo anterior; Los gastos de administración favorablemente tuvieron una tendencia a la baja en un 37.18%; Por lo que la utilidad operativa mejoró en un 2.83%, Pero sin embargo la Utilidad Neta disminuyó significativamente en S/. -37,671.00 y que representa el -35.05, lo que nos es favorable para la empresa. Según el análisis a través de los indicadores financieros, el índice de liquidez corriente nos muestra que la empresa cuenta con capacidad financiera de S/. 4.10 en el año 2015 y S/. 21.67 para cubrir sus obligaciones de corto plazo; Sin embargo el capital de trabajo disminuyó significativamente lo que no es favorable para la empresa; La Rotación del activo total es constante y las políticas aplicadas respecto a las Cuentas por cobrar no son las adecuadas siendo de 67 veces en el año 2014 y sólo 4 veces en el año 2015 los que no permiten generar efectivo en el corto plazo; La rentabilidad sobre capitales propios fue de 12.74% en el año 2014 y 8.01% en el año 2015, Y, La rentabilidad sobre la inversión muestra tendencia negativa ya que solo se obtuvo el 4.31% en el año 2014 y 3.20% en el año 2015, resultados muy bajos a los esperados por la empresa. En consecuencia del trabajo de investigación se divide en Cinco capítulos el cual son los siguientes: CAPITULO I: Planteamiento del problema de Investigación, antecedentes, y objetivos de la investigación, en donde se especifica el origen, el porqué de la investigación en base a los antecedentes existentes, para luego formular los objetivos de la investigación. CAPITULO II: Marco teórico, Marco Conceptual, e Hipótesis de la Investigación, en donde se conceptúan definiciones relacionadas al problema de investigación, para luego formular las hipótesis de la investigación. CAPITULO III: Método de Investigación, en el cual se muestran los métodos y técnicas para el análisis de los datos obtenidos. CAPITULO IV: Características del Área de Investigación: En el cual esta las características del ámbito de estudio CAPITULO V: Exposición y análisis de los Resultados; Muestra los resultados mediante cuadros y figuras, los que fueron analizados y discutidos como resultado de la aplicación de los Indicadores Financieros para llegar a dar las conclusiones y recomendaciones finale

Strongly tapered helical undulator system for FAST-GREENS installation

International audienceRadiaBeam, in collaboration with UCLA and Fermilab, is developing a strongly tapered helical undulator system for the Tapering Enhanced Stimulated Superradiant Amplification experiment at 515 nm (TESSA-515). The experiment will be carried out at the FAST facility at Fermilab as a Gamma-Ray high Efficiency ENhanced Source (FAST-GREENS). The undulator system was designed by UCLA, engineered by RadiaBeam, and will be installed on the beamline at Fermilab. The design is based on a permanent magnet Halbach scheme of four 1-meter long undulator sections; two of which have been completed and installed. The undulator period is fixed at 32 mm and the magnetic field amplitude can be tapered by tuning the gap along the interaction. Each magnet can be individually adjusted by 1 mm, offering up to 25% magnetic field tunability with a minimum gap of 5.58 mm. This paper discusses the design and engineering of the undulator system and the stage 0 installation status

Técnicas Básicas de Administración de Empresas

El objetivo principal es preparar a los participantes en el uso de una serie de técnicas que les permitan administrar una empresa pequeña, define los conceptos básicos y teorías sobre el proceso administrativo, con ejercicios y ejemplo

FAST-GREENS: A High Efficiency Free Electron Laser Driven by Superconducting RF Accelerator

International audienceIn this paper we’ll describe the FAST-GREENS experimental program where a 4 m-long strongly tapered helical undulator with a seeded prebuncher is used in the high gain TESSA regime to convert a significant fraction (up to 10 %) of energy from the 240 MeV electron beam from the FAST linac to coherent 515 nm radiation. We’ll also discuss the longer term plans for the setup where by embedding the undulator in an optical cavity matched with the high repetition rate from the superconducting accelerator (3,9 MHz), a very high average power laser source can be obtained. Eventually, the laser pulses can be redirected onto the relativistic electrons to generate by inverse compton scattering a very high flux of circularly polarized gamma rays for polarized positron production

FAST-GREENS: A High Efficiency Free Electron Laser Driven by Superconducting RF Accelerator

International audienceIn this paper we’ll describe the FAST-GREENS experimental program where a 4 m-long strongly tapered helical undulator with a seeded prebuncher is used in the high gain TESSA regime to convert a significant fraction (up to 10 %) of energy from the 240 MeV electron beam from the FAST linac to coherent 515 nm radiation. We’ll also discuss the longer term plans for the setup where by embedding the undulator in an optical cavity matched with the high repetition rate from the superconducting accelerator (3,9 MHz), a very high average power laser source can be obtained. Eventually, the laser pulses can be redirected onto the relativistic electrons to generate by inverse compton scattering a very high flux of circularly polarized gamma rays for polarized positron production

First Results of the IOTA Ring Research at Fermilab

The IOTA ring at Fermilab is a unique machine exclusively dedicated to accelerator beam physics R&D. The research conducted at IOTA includes topics such as nonlinear integrable optics, suppression of coherent beam instabilities, optical stochastic cooling and quantum science experiments. In this talk we report on the first results of experiments with implementations of nonlinear integrable beam optics. The first of its kind practical realization of a two-dimensional integrable system in a strongly-focusing storage ring was demonstrated allowing among other things for stable beam circulation near or at the integer resonance. Also presented will be the highlights of the world’s first demonstration of optical stochastic beam cooling and other selected results of IOTA’s broad experimental program

Neotropical ornithology: Reckoning with historical assumptions, removing systemic barriers, and reimagining the future

A major barrier to advancing ornithology is the systemic exclusion of professionals from the Global South. A recent special feature, Advances in Neotropical Ornithology, and a shortfalls analysis therein, unintentionally followed a long-standing pattern of highlighting individuals, knowledge, and views from the Global North, while largely omitting the perspectives of people based within the Neotropics. Here, we review current strengths and opportunities in the practice of Neotropical ornithology. Further, we discuss problems with assessing the state of Neotropical ornithology through a northern lens, including discovery narratives, incomplete (and biased) understanding of history and advances, and the promotion of agendas that, while currently popular in the north, may not fit the needs and realities of Neotropical research. We argue that future advances in Neotropical ornithology will critically depend on identifying and addressing the systemic barriers that hold back ornithologists who live and work in the Neotropics: unreliable and limited funding, exclusion from international research leadership, restricted dissemination of knowledge (e.g., through language hegemony and citation bias), and logistical barriers. Moving forward, we must examine and acknowledge the colonial roots of our discipline, and explicitly promote anti-colonial agendas for research, training, and conservation. We invite our colleagues within and beyond the Neotropics to join us in creating new models of governance that establish research priorities with vigorous participation of ornithologists and communities within the Neotropical region. To include a diversity of perspectives, we must systemically address discrimination and bias rooted in the socioeconomic class system, anti-Blackness, anti-Brownness, anti-Indigeneity, misogyny, homophobia, tokenism, and ableism. Instead of seeking individual excellence and rewarding top-down leadership, institutions in the North and South can promote collective leadership. In adopting these approaches, we, ornithologists, will join a community of researchers across academia building new paradigms that can reconcile our relationships and transform science. Spanish and Portuguese translations are available in the Supplementary Material.• Research conducted by ornithologists living and working in Latin America and the Caribbean has been historically and systemically excluded from global scientific paradigms, ultimately holding back ornithology as a discipline.• To avoid replicating systems of exclusion in ornithology, authors, editors, reviewers, journals, scientific societies, and research institutions need to interrupt long-held assumptions, improve research practices, and change policies around funding and publication.• To advance Neotropical ornithology and conserve birds across the Americas, institutions should invest directly in basic field biology research, reward collective leadership, and strengthen funding and professional development opportunities for people affected by current research policies.Peer reviewe