Hall Probe Bench for Cryogenic In Vacuum Undulator

The Helmholtz Zentrum Berlin HZB builds a 2m long in vacuum Hall probe measuring bench for the characterization of several in vacuum cryogenic undulators currently under development. Aceurate local magnetic measurements need a positioning control of about 5 Jlll. Fabrication tolerances and potentially strong temperature gradients require an active correction of the Hall probe movement along a straight line. The HZBbench employs a system of Iaser interferometers and positionsensitive detectors, which are used in a feed back loop for the Hall probe position and orientatio

A Canted Double Undulator System with a Wide Energy Range for EMIL

At BESSY II a canted double undulator system for the Energy Materials In situ Laboratory EMIL is under construction. The energy regime is covered with two undulators, an APPLE II undulator for the soft and a cryogenic permanent magnet undulator CPMU 17 for the hard photons. The layout and the performance of the undulators are presented in detail. The minimum of the vertical betatron function is shifted to the center of the CPMU 17. The neighboring quadrupoles and an additional quadrupole between the undulators control the vertical betatron function. Prior to the undulator installation a testing chamber with four movable vertical scrapers has been implemented at the CPMU 17 location. Utilizing the scrapers the new asymmetric lattice optics will be tested and optimize

Cryogenic Design of a PrFeB Based Undulator

A PrFeB based cryogenic undulator has been built at Helmholtz Zentrum Berlin HZB in collaboration with the Ludwig Maximilian University München LMU . LMU will operate the undulator at a laser plasma accelerator at the Max Planck Institut für Quantenoptik in Garching. The 20 period device has a period length of 9mm and a fixed gap of 2.5mm. The operation of a small gap device at a high emittance electron beam requires stable magnetic material. A high coercivity is achieved with PrFeB material cooled down to 20 30K. In this paper we present the mechanic, magnetic and cryogenic design and compare predictions with measured dat

Governance von Arbeit im deutschen Erwerbssystem: Alte, neue oder keine Normalitäten?

Seit dem Ende der Industriegesellschaft lastet auf Unternehmen, Arbeitsmärkten, Sozialversicherungssystemen, Arbeits- und Beschäftigungsbedingungen in Deutschland ein anhaltend starker Veränderungsdruck; sie werden in hohem Tempo reformiert, modernisiert und 'umgebaut'. Die Organisation von Arbeit wird verstärkt an die Erfordernisse der Märkte angepasst, neue Segmente prekärer Beschäftigung entstehen, aber gleichzeitig wachsen in vielen Bereichen auch die Handlungsspielräume und die Ansprüche der ArbeitnehmerInnen. Der Beitrag analysiert den Wandel insbesondere unter dem Gesichtspunkt von institutionellen Reformprozessen und den darauf bezogenen Reaktionen gesellschaftlicher Akteure. In Anlehnung an institutionentheoretische Konzepte werden für das deutsche Erwerbssystem vor allem unzureichende institutionelle Anpassungen an gesellschaftlichen Wandel (Drift) und Anlagerungen 'neuer' an bestehende Institutionen (Layering) diagnostiziert; gemeinsam fügen sich diese Muster in eine Dynamik der Dezentralisierung von Regulierungs- und Entscheidungskompetenzen. Die reflexiven Reaktionen kollektiver und individueller Akteure wirken sich in Prozessen der Einkapselung traditioneller Beschäftigungsmuster, der Re-Organisation von Machtkonstellationen oder der Kompensation zusätzlicher Belastungen aus. Die sozialen Konsequenzen folgen einer Logik der bipolaren Heterogenisierung, d.h. neben dem fortbestehenden, aber schrumpfenden Kern der Erwerbsbevölkerung, dessen Lebenszusammenhänge weiterhin durch Normalarbeitsverhältnis, Normalfamilie und Normalbiographie bestimmt sind, entwickelt sich eine wachsende Divergenz von einerseits privilegierten, andererseits prekarisierten Lebensverhältnissen. Die Verteilung auf diese verschiedenen Segmente scheint dabei vor allem vom Bildungsstatus und der Familienform abzuhängen.Since the end of the industrial era, a pressure to change weighs heavily on companies, labour markets, social systems, working and employment conditions. The German system of labour organization and regulation experiences a lasting sequence of rapid reforms and modernisations. Labour organization becomes increasingly adopted to the requirements of labour markets, and new segments of precarious employment emerge. At the same time, the scope of action and the claims of many employees are expanding. These processes are examined under the aspect of institutional change and resulting reactions of different actors. Firstly, the dynamics of the german labour system are characterized by either insufficient adjustment to societal changes or by appending some new elements to traditional institutions. Both of these processes blend in to the decentralisation of competences and liability for decision making and regulation. Secondly, reflexive reactions of collective and individual actors result in encapsulation of segments of traditional employment, in an ongoing reconfiguration of power relations or in a compensation of additional risks and burdens. The social consequences of these changes in the labour system, thirdly, generate a tendency towards a bipolar heterogeneity: Beyond the persisting, but shrinking, segment of groups with employment patterns characterized by 'traditional normality', the labour system brings about an increasing divergence of privileged on the one hand and precarious living conditions on the other hand. The allocation of individuals to these segments by the mechanisms of the labour system seems to depend mainly on the educational status and the family constellation

From Prototyping to Allotyping. The invention of change of use and the crisis of building types

The chapter analyses the invention and the form of the discourse on building conversion as one particular instance of redefining what a technology is and how it operates. I describe a shift from expert defined closure to lay based openness and tinkering as a shift from prototyping to allotyping: Since the early 1970s, change of use and building conversion have become a central and fashionable discourse among architects and architectural theorists. Before the 1970s, buildings were understood as technologies, as ‘society made durable’. The notion of building type was central to link a building to a given use. A bank was a bank because architects applied existing templates, prototypes, to turn a building into a bank. In the 1970s, suddenly buildings became flexible – discursively, since building conversion always existed: ‘Building type’ no longer was a meaningful link between a building and its use. A bank should not stay a bank, but become a hotel, a theatre or a flat, in short: an allotype. The chapter elucidate this central shift in thinking about buildings and reflects on the special case of allotyping buildings and how it continues to vex thinking about buildings