Proton Probing Measurement of Electric and Magnetic Fields Generated by ns and ps Laser-Matter Interactions

The use of laser-accelerated protons as a particle probe for the detection of electric fields in plasmas has led in recent years to a wealth of novel information regarding the ultrafast plasma dynamics following high intensity laser-matter interactions. The high spatial quality and short duration of these beams have been essential to this purpose. We will discuss some of the most recent results obtained with this diagnostic at the Rutherford Appleton Laboratory (UK) and at LULI - Ecole Polytechnique (France), also applied to conditions of interest to conventional Inertial Confinement Fusion. In particular, the technique has been used to measure electric fields responsible for proton acceleration from solid targets irradiated with ps pulses, magnetic fields formed by ns pulse irradiation of solid targets, and electric fields associated with the ponderomotive channelling of ps laser pulses in under-dense plasmas.

Accountability and its Metaphors: From Forum to Agora and Bazaar

In this paper we seek to develop a ‘relational’ perspective on accountability and on so-called ‘unaccountability.’. We focus on Mark Bovens’s use of the forum metaphor in his accountability model, arguing that his relational perspective is too narrow. We advocate instead a far broader and more fundamental engagement with the idea of relational accountability. Expanding the metaphors, we point to two other accountability spaces: ‘agora,’ a primordial accountability space and ‘bazaar,’ an emergent accountability space rooted in ground-level exchange between different actors. Assertions about ‘unaccountability,’ we argue, very often reflect a failure to appreciate the fundamentally relational nature of accountability: those who use such assertions as bases for action aimed at making situations, processes or people ‘more accountable’ in fact seek to assert or impose a certain form of relationship – one that is hierarchical and monopolistic – and reflect therefore a drive to power and domination.

Reframing the Favela, Remapping the City: Territorial Embeddedness and (Trans)locality in “Framing Content” on Brazilian Favela Blogs

In recent years, the internet has become a key site for the portrayal of Rio de Janeiro’s favelas. This article examines blogging by favela residents and argues that digital culture constitutes a vital, and as yet not systematically explored, arena of research on the representation of Rio de Janeiro and its favelas. Based on ethnographically inspired research carried out in 2009–2010, this article examines two examples of blog ‘framing content’ (a sidebar and a static page) encountered during fieldwork, which functioned to establish a concrete link between the posts on the blogs in question, their authors, and a named favela, even when the posts were not explicitly about that favela. At the same time, the framing content also made visible, and affirmed, the translocal connections between that favela, other favelas, and the city as a whole. These illustrative examples from a wider study show how favela bloggers are engaged in resignifying and remapping the relationships between different empirical scales of locality (and associated identities) in Rio de Janeiro, demonstrating the contribution an interdisciplinary approach to the digital texts and practices of favela residents can make to an understanding of the contemporary city and its representational conundrums, from the perspective of ‘ordinary practitioners’.