Surface electrons at plasma walls

In this chapter we introduce a microscopic modelling of the surplus electrons on the plasma wall which complements the classical description of the plasma sheath. First we introduce a model for the electron surface layer to study the quasistationary electron distribution and the potential at an unbiased plasma wall. Then we calculate sticking coefficients and desorption times for electron trapping in the image states. Finally we study how surplus electrons affect light scattering and how charge signatures offer the possibility of a novel charge measurement for dust grains.Comment: To appear in Complex Plasmas: Scientific Challenges and Technological Opportunities, Editors: M. Bonitz, K. Becker, J. Lopez and H. Thomse

Understanding residents’ capacities to support evacuated populations : A study of earthquake and tsunami evacuation for Napier Hill, Napier, Aotearoa New Zealand.

Due to a large regional subduction zone (the Hikurangi subduction zone) and localised faults, Napier City located on the East Coast of Aotearoa/New Zealand is vulnerable to earthquake and tsunami events. On feeling a long or strong earthquake people will need to evacuate immediately inland or to higher ground to avoid being impacted by a tsunami, of which the first waves could start to arrive within 20 minutes (based on the Hikurangi earthquake and tsunami scenario presented in Power et al., 2018). Napier Hill is one such area of higher land, and it is estimated that up to 12,000 people could evacuate there in the 20 minutes following a long or strong earthquake. To understand the capacity of Napier Hill residents to support evacuees, three focus groups were held with a diverse sample of residents from Napier Hill on 21 and 22 July 2019. A follow up email was sent to all participants a week after the focus groups, containing a link to a short six question survey, which was completed by 68 people, most of whom were additional to the focus group attendees. Data from the focus groups and the survey was analysed qualitatively using thematic analysis. The findings highlight that in general people were happy to host evacuees and offer support if they were in a position to do so. However, key issues in being able to offer support included the likely lack of resources available after a disaster, ranging from basic needs though to agency support. The research findings will directly inform Napier City Council and Hawke’s Bay Civil Defence Emergency Management Group’s planning for future readiness and response by providing valuable insights for evacuation planningfalseWellingtonHawke's Bay Civil Defence Emergency Management Grou

Challenges in QCD matter physics --The scientific programme of the Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sNN= 2.7--4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (μB> 500 MeV), effects of chiral symmetry, and the equation of state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2024, in the context of the worldwide efforts to explore high-density QCD matter

On the empirical content of the Beckerian marriage model

This note studies the empirical content of a simple marriage matching model with transferable utility, based on Becker (J Polit Econ 81:813–846, 1973). Under Becker’s conditions, the equilibrium matching is unique and assortative. However, this note shows that when the researcher only observes a subset of relevant characteristics, the unique assortative matching does not uniquely determine a distribution of observed characteristics. This precludes standard approaches to point estimation of the underlying model parameters. We propose a solution to this problem, based on the idea of “random matching.

Quasiconformal extensions, Loewner chains, and the lambda-Lemma

Becker (J Reine Angew Math 255: 23-43, 1972) discovered a sufficient condition for quasiconformal extendibility of Loewner chains. Many known conditions for quasiconformal extendibility of holomorphic functions in the unit disk can be deduced from his result. We give a new proof of (a generalization of) Becker's result based on Slodkowski's Extended.-Lemma. Moreover, we characterize all quasiconformal extensions produced by Becker's (classical) construction and use that to obtain examples in which Becker's extension is extremal (i. e. optimal in the sense of maximal dilatation) or, on the contrary, fails to be extremal.Peer reviewe