Abstract: An ionising particle analyser comprises a source of ionising particles, a charged particle detector, and an ionisable gas located between the source and the detector. The analyser further comprises a charged particle impeding device located between the source and the detector. The charged particle impeding device is arranged to be maintained in a first configuration at a potential to impede the passage of charged particles and pass uncharged particles.

Abstract: An ionising particle analyser comprises a source of ionising particles, a charged particle detector, and an ionisable gas located between the source and the detector. The analyser further comprises a charged particle impeding device located between the source and the detector. The charged particle impeding device is arranged to be maintained in a first configuration at a potential to impede the passage of charged particles and pass uncharged particles.

Abstract: A detection system comprising modulation means for applying a circular polarisation modulation to an incident beam of radiation, sample holding means through which the modulated beam is passed, a grating to diffract the beam of radiation, an array of solid state detectors arranged to receive different wavelengths of the beam, and processing means arranged to synchronise detected signals with the modulation applied by the modulation means, in order to measure the spectral circular dichroism of the sample.

Abstract: A method of identifying radiation detected in a wall-less proportional gas counter providing a stable pulse height spectrum. The method comprises i) transforming the detected pulse height spectrum (dn/dx) in accordance with the transform u=x1/2 where x represents the energy of the detected pulses in the original pulse height spectrum; ii) generating a normalized spectrum in u-space comprising a representation of dn/du as a function of u, where n is the detected pulse count as a function of x; iii) deconvoluting the normalized spectrum in u-space to enhance the spectrum; and iv) determining from the enhanced spectrum the energy (or energies) and/or the intensity (or intensities) of the detected radiation.

Abstract: A detection device for analyzing charged particles. The charged particle analyzer comprises a source of charged particles and a charged particle detector spaced from the source and immersed within the source in an ionizable gas. The detector comprises at least one pair of electrodes, characterized in that the electrodes of the pair are spaced apart by a distance that is substantialy less than the spacing between the source and detector. The electrodes of the pair are maintained at different potentials, and the source is maintained at a potential different from the potentials of the electrodes. The potentials are selected such that charged particles emitted by the source are attracted from the source toward each of the pair of electrodes and such that charged particles adjacent the detector are accelerated to energies sufficient to ionize the gas.