In Situ Characterization of Ultraintense Laser Pulses

We present a method for determining the characteristics of an intense laser pulse by probing it with a relativistic electron beam. After an initial burst of very high-energy $\gamma$-radiation the electrons proceed to emit a series of attosecond duration X-ray pulses as they leave the field. These flashes provide detailed information about the interaction, allowing us to determine properties of the laser pulse: something that is currently a challenge for ultra-high intensity laser systems.Comment: 9 pages, 8 figure

Marx's Economy and Beyond

Following renewed interest in Marx?s political economy in the wake of the financial crisis, the paper aims to make a contribution to debates re-evaluating Marx?s theory of capitalism and his conceptualisation of the relationship between the polity and economy. We bring together our approaches from political philosophy, economic sociology, and political economy, making the case for a renewal of historical materialism. We develop a perspective of a radically politicised economy, rather than treating polity and economy as separate spheres. The political implications of this perspective involve an insistence on political and economic democratisation and human rights as an integral part of any socially egalitarian alternatives to capitalist political economies. The paper, written without the full academic paraphernalia, engages with current defences of the classical Marxist understanding of exploitation, especially the labour theory of value, and presents an alternative, neo-Polanyian analysi

Natio et gens: Venice biennale 2009

The following is an informal reflection on the changing place of nationality and national consciousness in cultural life with reference to last year’s Biennale. Having drawn tentative inferences regarding the roles of these, we offer a selective review of what appear to us to be the most memorable national representations. These in turn suggest a paradoxical benefit which an awareness of localised histories may bring to artistic production

Transverse spreading of electrons in high-intensity laser fields

We show that for collisions of electrons with a high-intensity laser, discrete photon emissions introduce a transverse beam spread which is distinct from that due to classical (or beam shape) effects. Via numerical simulations, we show that this quantum induced transverse momentum gain of the electron is manifest in collisions with a realistic laser pulse of intensity within reach of current technology, and we propose it as a measurable signature of strong-field quantum electrodynamics.Comment: 5 pages, 3 figures. Accepted for publication in Physical Review Letter

SIMLA: Simulating laser-particle interactions via classical and quantum electrodynamics

We present the Fortran code SIMLA, which is designed for the study of charged particle dynamics in laser and other background fields. This can be done classically via the Landau-Lifshitz equation, or alternatively, via the simulation of photon emission events determined by strong-field quantum-electrodynamics amplitudes and implemented using Monte-Carlo type routines. Multiple laser fields can be included in the simulation and the propagation direction, beam shape (plane wave, focussed paraxial, constant crossed, or constant magnetic), and time envelope of each can be independently specified.Comment: Submitted to Comp. Phys. Comm. The associated computer program and corresponding manual will be made available on the CPC librar

Non-equilibrium phenomena and molecular reaction dynamics: mode space, energy space and conformer space

status: publishe

A Q-methodology study of parental understandings of infant immunisation : implications for health-care advice.

This study used Q-methodology to explore systematically parental judgements about infant immunisation. A total of 45 parents completed a 31-statement Q-sort. Data were collected after vaccination in general practitioner practices or a private day nursery. Q factor analysis revealed four distinct viewpoints: a duty to immunise based on medical benefits, child-orientated protection based on parental belief, concern and distress and surprise at non-compliance. Additionally, there was a common view among parents that they did not regret immunising their children. Implications of these results are discussed in terms of health-care policy and future research