Design and development of a linear travelling wave motor

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1990.Includes bibliographical references (leaves 117-119).by Ricardo J. Zemella.M.S

Simulation studies for dielectric wakefield programme at CLARA facility

Short, high charge electron bunches can drive high magnitude electric fields in dielectric lined structures. The interaction of the electron bunch with this field has several applications including high gradient dielectric wakefield acceleration (DWA) and passive beam manipulation. The simulations presented provide a prelude to the commencement of an experimental DWA programme at the CLARA accelerator at Daresbury Laboratory. The key goals of this program are: tunable generation of THz radiation, understanding of the impact of transverse wakes, and design of a dechirper for the CLARA FEL. Computations of longitudinal and transverse phase space evolution were made with Impact-T and VSim to support both of these goals.Comment: 10 Pages, 4 Figures, Proceedings of EAAC2017 Conferenc

The FLASHForward Facility at DESY

The FLASHForward project at DESY is a pioneering plasma-wakefield acceleration experiment that aims to produce, in a few centimetres of ionised hydrogen, beams with energy of order GeV that are of quality sufficient to be used in a free-electron laser. The plasma wave will be driven by high-current density electron beams from the FLASH linear accelerator and will explore both external and internal witness-beam injection techniques. The plasma is created by ionising a gas in a gas cell with a multi-TW laser system, which can also be used to provide optical diagnostics of the plasma and electron beams due to the <30 fs synchronisation between the laser and the driving electron beam. The operation parameters of the experiment are discussed, as well as the scientific program.Comment: 19 pages, 9 figure

Dilatação dos confins: caminhos, vilas e cidades na formação da Capitania de São Paulo (1532-1822)

Este ensaio analisa a formação da rede urbana das capitanias de São Vicente e Santo Amaro, depois unidas na Capitania de São Paulo. Discute o processo de apropriação do sertão, a pulsação e dilatação dos confins ao sabor dos deslocamentos humanos e de interesses políticos. Interpreta o papel de capelas, freguesias, vilas e cidades no controle e produção de territórios metropolitanos em solos ultramarinos.This essay analyzes the development of urban networks in the Captaincies of São Vicente and Santo Amaro, later merged into the Captaincy of São Paulo. It discusses the process of appropriation of the sertão (backcountry), the commotion and expansion beyond the confines to the tune of population movements and political interests. The paper also interprets the role of chapels, parishes, villages and towns in initiatives to create and control metropolitan areas on overseas soil

A História da Alimentação: balizas historiográficas

Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

Status Update of the Fast Energy Corrector Cavity at FLASH

Linear accelerator facilities driving a free-electron laser require femtosecond precision synchronization between external laser systems and the electron beam. Such high precision is required for pump-probe experiments and also for example for the electron bunch injection into a plasma bubble for laser plasma acceleration. An upgrade of the fast intra-train beam-based feedback system is planned at the Free-Electron Laser FLASH in Hamburg, Germany. This linear accelerator is based on superconducting (SRF) technology operating with pulse trains of maximum 1 MHz bunch repetition rate. Arrival time fluctuations of the electron beam are correctable by introducing small energy modulations prior to the magnetic bunch compressor. This contribution focuses on the design and the characterization of a normal-conducting RF (NRF) cavity with large bandwidth, mandatory to correct fast arrival time fluctuations. The cavity has recently been installed in the FLASH beamline. First measurements with the new cavity will be presented