The characteristics of an Elekta Precise treatment machine with a gating interface were investigated. Three detectors were used: a Farmer ionisation chamber; a MatriXX ionisation chamber array and an in-house, single pulse-measurement ionisation chamber (IVC). Measurements were made of dosimetric accuracy, flatness and symmetry characteristics and duty cycle for a range of beam-on times and gat...

A generic method to screen for new or unexpected contaminants at ppm levels in food has been developed. The method comprises an acidic acetonitrile extraction, detection with ultra-high-pressure liquid chromatography coupled to electrospray ionisation time-of-flight mass spectrometry and statistical evaluation using a metabolomics approach comparing suspected contaminated food with uncontaminat...

We calculate the ionisation fraction in protostellar disk models using a number of different chemical reaction networks, including gas–phase and gas–grain reaction schemes. The disk models we consider are conventional α–disks, which include viscous heating and radiative cooling. The primary source of ionisation is assumed to be X–ray irradiation from the central star. For most calculations we a...

Mass spectrometry imaging (MSI) is a powerful tool in metabolomics and proteomics for the spatial localization and identification of pharmaceuticals, metabolites, lipids, peptides and proteins in biological tissues. However, sample preparation remains a crucial variable in obtaining the most accurate distributions. Common washing steps used to remove salts, and solvent-based matrix application,...

The similarity between observed velocity structures of Al III and singly ionised species in damped Lyα systems (DLAs) suggests the presence of ionised gas in the regions where most metal absorption lines are formed. To explore the possible implications of ionisation effects we construct a simplified two-region model for DLAs consisting of an ionisation bounded region with an internal radiation ...

Electron-electron coincidence experiments have experienced over the past twenty years an increasingly rapid expansion and application to many different fields. Among them, the (e,2e) spectroscopy has been successfully used to investigate either the target electronic structure or the ionisation dynamics. The capability of this spectroscopy to investigate single particle properties in atoms, mole...

Two vertical cosmic ray telescopes for atmospheric cosmic ray ionisation event detection are compared. Counter A, designed for low power remote use, was deployed in the Welsh mountains; its event rate increased with altitude as expected from atmospheric cosmic ray absorption. Independently, Counter B’s event rate was found to vary with incoming particle acceptance angle. Simultaneous co-located...

The SPARC-EBIT (fig.1) is an Electron Beam Ion Trap (from DREEBIT, Dresden) that will be used for tests and offline measurements, firstly for HITRAP, and later for SPARC (Stored Particle Atomic physics Research Collaboration). In the EBIT the ions are produced by electron impact ionisation of gas atoms by an intense electron beam. The magnetic field of a permanent magnet arrangement focuses the...

The photoionisation spectrum of atomic phosphorus prepared by successive abstraction reactions involving H atoms and PH,, is presented from its ionisation threshold to 765 A. Prominent autoionisation structure is observed between the fine-structure limits 3P2-3P, near the ionisation threshold. In addition, a window resonance series is seen, involving inner s-shell excitation to. .. ('S)np 4P st...

A three dimensional Smoothed Particle Hydrodynamical (SPH) model has been extended to study the radiative driven implosion effect of massive stars on the dynamical evolutions of surrounding molecular clouds. The new elements in the upgraded code are the inclusion of Lyman continuum in the incident radiation flux and the treatment of hydrogen ionisation process; introducing ionisation heating & ...