Migration routes of the Grant's Zebra

This is where the abstract of this record would appear. This is only demonstration data

Selective Deuterium Ion Acceleration Using the Vulcan PW Laser

We report on the successful demonstration of selective acceleration of deuterium ions by target-normal sheath acceleration (TNSA) with a high-energy petawatt laser. TNSA typically produces a multi-species ion beam that originates from the intrinsic hydrocarbon and water vapor contaminants on the target surface. Using the method first developed by Morrison, et al.,$^{1}$ an ion beam with $>$99$\%$ deuterium ions and peak energy 14 MeV/nucleon is produced with a 200 J, 700 fs, $>10^{20} W/cm^{2}$ laser pulse by cryogenically freezing heavy water (D$_{2}$O) vapor onto the rear surface of the target prior to the shot. Within the range of our detectors (0-8.5$^{\circ}$), we find laser-to-deuterium-ion energy conversion efficiency of 4.3$\%$ above 0.7 MeV/nucleon while a conservative estimate of the total beam gives a conversion efficiency of 9.4$\%$.Comment: 5 pages, 5 figure

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C6+, O8+, etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented.Comment: 7 pages, 7 figure

Assessing community noise annoyance: a review of two decades of the international technical specification ISO/TS 15666:2003

The robust assessment of noise annoyance is of key importance given that it is the most prevalent community response in populations exposed to environmental noise. In 1993 the International Commission on Biological Effects of Noise Community Response to Noise team began formalizing a standardized methodology for assessing noise annoyance, which resulted in reporting guidelines and recommendations later published as a Technical Specification (TS) by the International Standards Organization in 2003 (ISO/TS 15666: 2003). This TS, intended to inform the international community on the quantification of the exposure-response relationship between noise exposure and annoyance, has been in circulation for nearly two decades and has been updated in 2021 (ISO/TS 15666: 2021) by an international working group (ISO TC43/SC1/WG62). This paper reviews use of the 2003 TS, identifies common adaptations in use and summarizes the revisions. Methodological issues arising from the use of the 5-point verbal and the 11-point numeric scale questions and the scoring of ‘highly annoyed’ are discussed. The revisions are designed to encourage further standardization in noise annoyance research. The paper highlights research needs that if addressed would strengthen the methodology underlying the assessment of noise annoyance including multidimensional assessments of annoyance

Known mutator alleles do not markedly increase mutation rate in clinical Saccharomyces cerevisiae strains

Natural selection has the potential to act on all phenotypes, including genomic mutation rate. Classic evolutionary theory predicts that in asexual populations, mutator alleles, which cause high mutation rates, can fix due to linkage with beneficial mutations. This phenomenon has been demonstrated experimentally and may explain the frequency of mutators found in bacterial pathogens. By contrast, in sexual populations, recombination decouples mutator alleles from beneficial mutations, preventing mutator fixation. In the facultatively sexual yeast Saccharomyces cerevisiae, segregating alleles of MLH1 and PMS1 have been shown to be incompatible, causing a high mutation rate when combined. These alleles had never been found together naturally, but were recently discovered in a cluster of clinical isolates. Here we report that the incompatible mutator allele combination only marginally elevates mutation rate in these clinical strains. Genomic and phylogenetic analyses provide no evidence of a historically elevated mutation rate. We conclude that the effect of the mutator alleles is dampened by background genetic modifiers. Thus, the relationship between mutation rate and microbial pathogenicity may be more complex than once thought. Our findings provide rare observational evidence that supports evolutionary theory suggesting that sexual organisms are unlikely to harbour alleles that increase their genomic mutation rate

Laser-driven X-ray and neutron source development for industrial applications of plasma accelerators

Pulsed beams of energetic X-rays and neutrons from intense laser interactions with solid foils are promising for applications where bright, small emission area sources, capable of multi-modal delivery are ideal. Possible end users of laser-driven multi-modal sources are those requiring advanced non-destructive inspection techniques in industry sectors of high value commerce such as aerospace, nuclear and advanced manufacturing. We report on experimental work that demonstrates multi-modal operation of high power laser-solid interactions for neutron and X-ray beam generation. Measurements and Monte-Carlo radiation transport simulations show that neutron yield is increased by a factor ~ 2 when a 1mm copper foil is placed behind a 2mm lithium foil, compared to using a 2cm block of lithium only. We explore X-ray generation with a 10 picosecond drive pulse in order to tailor the spectral content for radiography with medium density alloy metals. The impact of using >1ps pulse duration on laser-accelerated electron beam generation and transport is discussed alongside the optimisation of subsequent Bremsstrahlung emission in thin, high atomic number target foils. X-ray spectra are deconvolved from spectrometer measurements and simulation data generated using the GEANT4 Monte-Carlo code. We also demonstrate the unique capability of laser-driven X-rays in being able to deliver single pulse high spatial resolution projection imaging of thick metallic objects. Active detector radiographic imaging of industrially relevant sample objects with a 10ps drive pulse is presented for the first time, demonstrating that features of 200µm size are resolved when projected at high magnification