Neutralization principles for the Extraction and Transport of Ion Beams

The strict application of conventional extraction techniques of ion beams from a plasma source is characterized by a natural intensity limit determined by space charge.The extracted current may be enhanced far beyond this limit by neutralizing the space charge of the extracted ions in the first extraction gap of the source with electrons injected from the opposite side. The transverse and longitudinal emittances of a neutralized ion beam, hence its brightness, are preserved. Results of beam compensation experiments, which have been carried out with a laser ion source, are resumed for proposing a general scheme of neutralizing ion sources and their adjacent low-energy beam transport channels with electron beams. Many technical applications of high-mass ion beam neutralization technology may be identified: the enhancement of ion source output for injection into high-intensity, low-and high-energy accelerators, or ion thrusters in space technology, for the neutral beams needed for plasma heating of magnetic confinement fusion devices, and for future accelerator-driven systems for fusion, fission and nuclear waste incineration

Charge and Current Compensation of Intense Charged Beams in Future Accelerators

Proposals for future high-energy accelerators are characterized by demands for increasingly intense and energetic beams. The classical operation of high-current accelerators is severely constrained by collective electrodynamic phenomena, such as problems related to space-charge, to high-current flow, to beamstrahlung and pair production. These detrimental electrodynamic effects dominate the dynamic s and the collision interactions of high-intensity beams. With the introduction of soft space-charge and current compensation techniques utilizing low- to medium-energy lepton beams with charge polari ty opposite to that of the beams to be neutralized, all electromagnetic high-intensity limitations may be removed. The application of beam compensation is proposed for various sections of different ty pes of classical accelerator systems, such as for ion sources and the low-energy beam transport sections of ion linacs, for the crossing points of circular and linear colliders and for the final focii of ion beam fusion drivers. The design and the operation of partially compensated accelerators becomes much more comfortable and design goals can be reached more easily without any significant electro magnetic perturbation. The ingredients of neutralization technology low-energy electron and positron beams are state-of-the-art and, as such, applicable today. Several methods of smooth beam compe nsation can be identified and must be studied and selected for each specific case. Practical experience has to be gained in dedicated pilot experiments

Biomolecular imaging and electronic damage using X-ray free-electron lasers

Proposals to determine biomolecular structures from diffraction experiments using femtosecond X-ray free-electron laser (XFEL) pulses involve a conflict between the incident brightness required to achieve diffraction-limited atomic resolution and the electronic and structural damage induced by the illumination. Here we show that previous estimates of the conditions under which biomolecular structures may be obtained in this manner are unduly restrictive, because they are based on a coherent diffraction model that is not appropriate to the proposed interaction conditions. A more detailed imaging model derived from optical coherence theory and quantum electrodynamics is shown to be far more tolerant of electronic damage. The nuclear density is employed as the principal descriptor of molecular structure. The foundations of the approach may also be used to characterize electrodynamical processes by performing scattering experiments on complex molecules of known structure.Comment: 16 pages, 2 figure

Geschäftsanalyse im Kontext der Unternehmensarchitektur

Zusammenfassung: Die Wandlungsfähigkeit von Organisationen ist ein wesentlicher Erfolgsfaktor, zu dem die Unternehmensarchitektur einen wichtigen Beitrag leisten kann. Geschäftsanalysen liefern die Voraussetzungen für das Verständnis und die transparente Weiterentwicklung des Geschäftsmodells und die dafür notwendige Ausrichtung der Informationstechnologie. Vor diesem Hintergrund wird am Beispiel eines Schweizerischen Versicherungsunternehmens gezeigt, wie durch Geschäftsanalyse einerseits das Verständnis des Geschäftsmodells gefördert und andererseits die Abstimmung zwischen Geschäfts- und IT-Architektur unterstützt wird. Ferner wird ein Ansatz vorgestellt, der verschiedene Ziele und Typen der Geschäftsanalyse im Kontext von Unternehmensarchitekturen zusammenführ

Ion Beam Neutralization with Ferroelectrically Generated Electron Beams

A technique for ion beam space-charge neutralization with pulsed electron beams is described. The intensity of multiply-charged ions produced with a laser ion source can be enhanced or decreased separately with electron beam trains of MHz repetition rate. These are generated with ferroelectric cathodes, which are pulsed in synchronization with the laser ion source. The pulsed electron beams guide the ion beam in a similar way to the alternating gradient focusing of charged particle beams in circular accelerators such as synchrotrons. This new neutralization technology overcomes the Langmuir Child space-charge limit and may in future allow ion beam currents to be transported with intensities by orders of magnitude higher than those which can be accelerated today in a single vacuum tube

Knowledge transfer between globally dispersed units at BMW

Purpose - Building on the social network view and new product development perspective, the purpose of this paper is to examine how knowledge is transferred between identical, yet geographically distant units within a multinational corporation. Design/methodology/approach - An embedded case study of Bayerische Motoren Werke (BMW) examining core drivers that impact on inter-unit knowledge transfers between six events and exhibitions (E&E) units located in Europe, Asia, and Australasia. Findings - The data highlight that effective knowledge transfer between E&E units depends on a combination of key drivers, such as social network ties, absorptive capacity, learning adaptiveness, and communication channels. The findings suggest that the search for and transfer of knowledge depends foremost on the applicability of context-specific knowledge rather than its complexity. Research limitations/implications - The focus is on one specific manufacturing sector and specific drivers to knowledge transfer in this sector, limiting the generalisation of the findings. Also, the findings were drawn from a limited sample of in-depth practitioner interviews and did not integrate any outcome measures to successful knowledge transfer in their approach. Practical implications - The paper offers guidelines for firms and specifically E&E managers to observe the specificity of knowledge and how this affects its limited applicability for other identical units. Originality/value - Managers foremost need is to examine the unique context under which knowledge is acquired; only then are they in a position to decide how much knowledge transfer via different network and communication channels is needed between geographically dispersed E&E units.Griffith Business School, Department of International Business and Asian StudiesNo Full Tex

Sykepleierens erfaringer som pårørende : Hvilke personlige erfaringer har sykepleiere som er pårørende til et nært familiemedlem?

Bakgrunn: Litteraturen skiller mellom ulike typer av roller, og viser at det kan være et dilemma å inneha flere roller samtidig. Disse dilemmaene kan føre til rollekonflikter. Det er relativt lite kunnskap på feltet om det å ha rollen som både profesjonell helsearbeider og nær pårørende. Den manglende kunnskapen på feltet og egen opplevd erfaring som pårørende og sykepleier er derfor bakgrunnen for arbeidet med denne tematikken. Formål: Formål med studien er å undersøke hvilke erfaringer sykepleiere har i rollen som pårørende. Metode: Oppgaven er en kvalitativ studie. Det er utført kvalitative forskningsintervju med 7 sykepleiere som har pårørendeerfaring til et nært familiemedlem. Det empiriske materialet er analysert ved hjelp av meningsfortetting innenfor en fortolkende tradisjon. Teoretisk perspektiv: Den teoretiske referanserammen er hentet fra både sosiologien og sykepleiefaget. Sosiologien er opptatt av å analysere samhandlingen mellom mennesker innenfor ulike sosiale systemer. Hvordan relasjonene er mellom mennesker og hvilke forventninger man har til rollene avgjør hvordan mennesker håndterer å ha flere roller samtidig. For å belyse pårørendeperspektivet er tema som hvem den pårørende er, pårørendes erfaringer og opplevelsen av avmakt sett nærmere på. For å belyse sykepleierperspektivet er omsorg, skjønnet, sykepleiefokus og sykepleiernes erfaringer løftet frem. Det benyttes også forskningsartikler for å belyse sykepleieres erfaringer som pårørende og sykepleier. Resultater: Sykepleiere med pårørendeerfaring er ofte kritiske pårørende og ikke alltid enige i behandlingen av pasienten. De sier samtidig at de har opplevd mye god pleie av pasienten, men savner initiativ fra personalet i forhold til informasjon og tiltak. Flere informanter opplevde situasjoner hvor de stilte spørsmålstegn ved fagkunnskapen til personalet, og hvordan de tilegnet seg ny kunnskap. Hvis noe ikke er bra sier de fra på en forsiktig måte, med faglige argument. Om forholdet til søsken hadde informantene ulike erfaringer, noen opplevde det som problematisk, andre ikke. Alle la vekt på viktigheten av støtte fra søsken. Konklusjon: Sykepleiere med pårørendeerfaring greier ikke å være enten 100 % pårørende eller 100 % sykepleier, de er i en spenning mellom rollene. Det er vanskelig å være profesjonell, de har en dobbeltrolle som gir konsekvenser for hver av rollene. De opplever en rollekonflikt. De bruker egne erfaringer til beste for pasienten, både i rollen som pårørende og i rollen som sykepleier, og legger vekt på å ta både pasient og pårørende på alvor. Nøkkelord: Sykepleier, sykepleie, pårørende, omsorg, rolle, rolleteori, rollekonflikt, dobbeltrolle, pårørenderolle, sykepleierrolle, nurse, nursing, nursing role, caregivers, double duty caregivers, relatives