The Quadratic Coefficient of the Electron Cloud Mapping

The Electron Cloud is an undesirable physical phenomenon which might produce single and multi-bunch instability, tune shift, increase of pressure ultimately limiting the performance of particle accelerators. We report our results on the analytical study of the electron dynamics.Comment: 5 pages, 7 figures, presented at ECLOUD12: Joint INFN-CERN-EuCARD-AccNet Workshop on Electron-Cloud Effects, La Biodola, Isola d Elba, Italy, 5-9 June 201

Coupling Impedances for Perforated Beam Pipes with General Shape from Impedance Boundary Condition

We introduce an equivalent wall impedance to describe the electromagnetic boundary conditions at perforated pipe walls. The new impedance boundary condition, together with our general formulae for computing longitudinal and transverse beam coupling impedances in complex heterogeneous pipes, provides a good trade-off between computational accuracy and ease

Maps for Electron Clouds: Application to LHC Conditioning

In this communication we present a generalization of the map formalism, introduced in [1] and [2], to the analysis of electron flux at the chamber wall with particular reference to the exploration of LHC conditioning scenarios.Comment: 3 pages, 4 figure

Economic reasoning and interaction in socially extended market institutions

An important part of what it means for agents to be situated in the everyday world of human affairs includes their engagement with economic practices. In this paper, we employ the concept of cognitive institutions in order to provide an enactive and interactive interpretation of market and economic reasoning. We challenge traditional views that understand markets in terms of market structures or as processors of distributed information. The alternative conception builds upon the notion of the market as a scaffolding institution. Introducing the concept of market as a socially extended cognitive institution we go beyond the notion of scaffolding to provide an enactive view of economic reasoning that understands the market participant in terms of social interactive processes and relational autonomy. Markets are more than inert devices for information processing; they can be viewed as highly scaffolded, where strong constraints and incentives predictably direct agents\u27 behavior. Building on this idea we argue that markets emerge from (a) the economic interaction of both supply and demand sides, in continual and mutual interplay, and (b) more basic social interactions. Consumer behavior in the marketplace is complex, not only contributing to determine the market price, but also extending the consumer\u27s cognitive processes to reliably attain a correct evaluation of the good. Moreover, this economic reasoning is socially situated and not something done in isolation from other consumers. From a socially situated, interactive point of view buying or not buying a good is something that enacts the market. This shifts the status of markets from external institutions that merely causally affect participants\u27 cognitive processes to social institutions that constitutively extend these cognitive processes. On this view the constraints imposed by social interactions, as well as the possibilities enabled by such interactions, are such that economic reasoning is never just an individual process carried out by an autonomous individual, classically understood. In this regard, understanding the concept of relational autonomy allows us to see how economic reasoning is always embodied, embedded in, and scaffolded by intersubjective interactions, and how such interactions make the market what it is

A Formula of the Electron Cloud Linear Map Coefficient in a Strong Dipole

Electron cloud effects have recognized as as one of the most serious bottleneck for reaching design performances in presently running and proposed future storage rings. The analysis of these effects is usually performed with very time consuming simulation codes. An alternative analytic approach, based on a cubic map model for the bunch-to-bunch evolution of the electron cloud density, could be useful to determine regions in parameters space compatible with safe machine operations. In this communication we derive a simple approximate formula relating the linear coefficient in the electron cloud density map to the parameters relevant for the electron cloud evolution with particular reference to the LHC dipoles.Comment: 3 pages, 5 figures. Proceeding of IPAC 201

Maps for electron clouds: application to LHC

In this communication we show that the cubic map formalism introduced in [1] to model electron cloud in RHIC is also reliable in the range of typical LHC parameters