Weibel-induced filamentation during an ultrafast, laser-driven plasma expansion

The development of current instabilities behind the front of a cylindrically expanding plasma has been investigated experimentally via proton probing techniques. A multitude of tubelike filamentary structures is observed to form behind the front of a plasma created by irradiating solid-density wire targets with a high-intensity (I~1019??W/cm2), picosecond-duration laser pulse. These filaments exhibit a remarkable degree of stability, persisting for several tens of picoseconds, and appear to be magnetized over a filament length corresponding to several filament radii. Particle-in-cell simulations indicate that their formation can be attributed to a Weibel instability driven by a thermal anisotropy of the electron population. We suggest that these results may have implications in astrophysical scenarios, particularly concerning the problem of the generation of strong, spatially extended and sustained magnetic fields in astrophysical jets.

Sheath dynamics observed in a 13.56 MHz-driven plasma

We have established, through time correlated plasma emission and electrode and plasma potential measurements, that the near electrode emission observed in asymmetric capacitively coupled 13.56 MHz-driven hydrogen plasmas is caused by field reversal that leads to sheath collapse. Near-electrode emission has now been observed in Ar and He. The field reversal appears to be due to collision-induced electron drag. (C) 1997 American Institute of Physics.

Biological effectiveness on live cells of laser driven protons at dose rates exceeding 109 Gy/s

The ultrashort duration of laser-driven multi-MeV ion bursts offers the possibility of radiobiological studies at extremely high dose rates. Employing the TARANIS Terawatt laser at Queen's University, the effect of proton irradiation at MeV-range energies on live cells has been investigated at dose rates exceeding 109 Gy/s as a single exposure. A clonogenic assay showed consistent lethal effects on V-79 live cells, which, even at these dose rates, appear to be in line with previously published results employing conventional sources. A Relative Biological Effectiveness (RBE) of 1.4±0.2 at 10% survival is estimated from a comparison with a 225 kVp X-ray source.

Music in mind, a randomized controlled trial of music therapy for young people with behavioural and emotional problems: study protocol

Aims. This article is a report of a trial protocol to determine if improvizational music therapy leads to clinically significant improvement in communication and interaction skills for young people experiencing social, emotional or behavioural problems. Background. Music therapy is often considered an effective intervention for young people experiencing social, emotional or behavioural difficulties. However, this assumption lacks empirical evidence. Study design. Musicinmindisamulti-centredsingle-blindrandomizedcontrolledtrial involving 200 young people (aged 8–16 years) and their parents. Eligible participants willhaveaworkingdiagnosiswithintheambitofInternational ClassificationofDisease 10 Mental and Behavioural Disorders and will be recruited over 15 months from six centres within the Child and Adolescent Mental Health Services of a large health and social care trust in Northern Ireland. Participants will be randomly allocated in a 1:1 ratio to receive standard care alone or standard care plus 12 weekly music therapy sessions delivered by the Northern Ireland Music Therapy Trust. Baseline data will be collectedfromyoungpeopleandtheirparentsusingstandardizedoutcomemeasuresfor communicative and interaction skills (primary endpoint), self-esteem, social functioning, depressionandfamilyfunctioning.Follow-updatawillbecollected1and13 weeks afterthefinalmusictherapysession.Acost-effectivenessanalysiswillalsobecarriedout. Discussion. This study will be the largest trial to date examining the effect of music therapy on young people experiencing social, emotional or behavioural difficulties and will provide empirical evidence for the use of music therapy among this population. Trial registration. This study is registered in theISRCTNRegister,ISRCTN96352204. Ethical approval was gained in October 2010.

Compost city: underground music, collapsoscapes and urban regeneration

This paper looks at the recent history of Hulme, Manchester, which during the 1980s was home to many of the most successful bands of the post-punk era. This flourishing of underground music was not planned, however. It emerged, through a complex network of urban forces, some physical, some social. The paper develops the concept of the ‘compost city’ a laissez-faire approach to the management of urban culture, which is oppositional to the current vogue for more hands-on cultural industries management.

The Sound of Becoming: Moving Towards a Virtual Music

In 1985 Jacques Attali proposed a new modality for music. He suggests that there be “not a new music, but a new way of making music... a radically new form of the insertion of music into communication” (Attali 134). What Attali foretold has become a firm reality in contemporary musical practice. One has only to look at any current musical activity to encounter work that relies heavily on real-time interaction and dynamic generation and/or modification of materials. But why is this ontologically different ‘mode of essentially interactive and transformative existence’ (Ziarek 195), this ‘new way of making music’, so attractive to contemporary artists? What is motivating artists to abandon a production model in favor of a model of real-time interactive exploration? I will argue that at the foundation of this new artistic ontology lies Deleuze’s concept of the virtual. It is a recognition of the virtual power of music, that music making can be an act of invention, a process where one can discover something never before experienced.