Microwave generation for magnetic fusion energy applications. Progress report, July 15, 1992--July 14, 1993

This work strives to develop high average power FELs at voltages below I MV allowing for smaller and less costly power supplies. To achieve operation of an FEL with 100 GHZ {approx_lt} f {approx_lt} 150 GHz and with relatively modest voltage, we have been investigating the use of small period ({lambda}{sub {omega}} {approximately} 1 cm) planar wiggler magnets together with sheet electron beams. The sheet beam geometry allows for an FEL interaction region in the form of a narrow slit with high wiggler field at the center plane where the electrons are concentrated. The total current and power may then be increased without making current density excessive by increasing the wide dimension of the sheet beam. Sheet beam FEL design parameters for both a Proof-of-Principle (PoP) FEL experiment, which is current in progress, and an ITER relevant FEL design are shown. A central issue in the sheet beam FEL concept is propagation of the beam through the interaction region without excessive interception by the walls. In section 2 below we describe a successful experimental demonstration of sheet beam propagation through a 56 period uniform wiggler. Cold testing and initial hot test operation of the (PoP) FEL amplifier are also described. Finally, we present a theoretical investigation of the bandwidth of an FEL amplifier with a tapered wiggler operating in saturation is described

Financing of U.S. Biomedical Research and New Drug Approvals across Therapeutic Areas

We estimated U.S. biomedical research funding across therapeutic areas, determined the association with disease burden, and evaluated new drug approvals that resulted from this investment.We calculated funding from 1995 to 2005 and totaled Food and Drug Administration approvals in eight therapeutic areas (cardiovascular, endocrine, gastrointestinal, genitourinary, HIV/AIDS, infectious disease excluding HIV, oncology, and respiratory) primarily using public data. We then calculated correlations between funding, published estimates of disease burden, and drug approvals. Financial support for biomedical research from 1995 to 2005 increased across all therapeutic areas between 43% and 369%. Industry was the principal funder of all areas except HIV/AIDS, infectious disease, and oncology, which were chiefly sponsored by the National Institutes of Health (NIH). Total (rho = 0.70; P = .03) and industry funding (rho = 0.69; P = .04) were correlated with projected disease burden in high income countries while NIH support (rho = 0.80; P = .01) was correlated with projected disease burden globally. From 1995 to 2005 the number of new approvals was flat or declined across therapeutic areas, and over an 8-year lag period, neither total nor industry funding was correlated with future approvals.Across therapeutic areas, biomedical research funding increased substantially, appears aligned with disease burden in high income countries, but is not linked to new drug approvals. The translational gap between funding and new therapies is affecting all of medicine, and remedies must include changes beyond additional financial investment

The political economy of trade and migration: evidence from the U.S. Congress

We systematically examine the drivers of U.S. congressmen's votes on trade and migration reforms since the 1970's. Standard trade theory suggests that reforms that lower barriers to goods and migrants should have similar distributional effects, hurting low-skilled U.S. workers while benefiting high-skilled workers. In line with this prediction, we find that House members representing more skilled labor abundant districts are more likely to support both trade and migration liberalization. Still, important differences exist: Democrats favor trade reforms less than Republicans, while the opposite is true for immigration reforms; welfare state considerations and network effects shape support for immigration, but not for trade

DIPLOMACIA E POLÍTICA DOMÉSTICA: A LÓGICA DOS JOGOS DE DOIS NÍVEIS

A política doméstica e as relações internacionais com freqüência são inextricavelmente vinculadas; todavia,as teorias existentes (particularmente as estatocêntricas) não levam adequadamente em consideraçõestais vínculos. Quando os líderes nacionais devem obter as ratificações (formais ou informais) dos membrosde seus parlamentos para um acordo internacional, seus comportamentos em negociações refletem os imperativossimultâneos tanto de um jogo de política doméstica quanto de um jogo de política internacional.Usando exemplos de cúpulas econômicas ocidentais, das negociações do Canal do Panamá e do Tratado deVersalhes, dos programas de estabilização do Fundo Monetário Internacional, da Comunidade Européia ede muitos outros contextos diplomáticos, o artigo oferece uma teoria da ratificação. Ele enfatiza o papel daspreferências, coalizões, instituições e práticas domésticas, das estratégias e táticas dos negociadores, daincerteza, das reverberações domésticas das pressões externas e o papel dos interesses do negociador-chefe.Essa teoria de “jogos de dois níveis” também pode ser aplicável a muitos outros fenômenos políticos, taiscomo a dependência, os comitês legislativos e as coalizões multipartidárias

Microwave generation for magnetic fusion energy applications

This work strives to develop high average power FELs at voltages below I MV allowing for smaller and less costly power supplies. To achieve operation of an FEL with 100 GHZ [approx lt] f [approx lt] 150 GHz and with relatively modest voltage, we have been investigating the use of small period ([lambda][sub [omega]] [approximately] 1 cm) planar wiggler magnets together with sheet electron beams. The sheet beam geometry allows for an FEL interaction region in the form of a narrow slit with high wiggler field at the center plane where the electrons are concentrated. The total current and power may then be increased without making current density excessive by increasing the wide dimension of the sheet beam. Sheet beam FEL design parameters for both a Proof-of-Principle (PoP) FEL experiment, which is current in progress, and an ITER relevant FEL design are shown. A central issue in the sheet beam FEL concept is propagation of the beam through the interaction region without excessive interception by the walls. In section 2 below we describe a successful experimental demonstration of sheet beam propagation through a 56 period uniform wiggler. Cold testing and initial hot test operation of the (PoP) FEL amplifier are also described. Finally, we present a theoretical investigation of the bandwidth of an FEL amplifier with a tapered wiggler operating in saturation is described