Abstract: A method of introducing ions into an ion trap and an ion storage apparatus are described. Introduction means are used to introduce first ions into an ion trap through an entrance aperture to the ion trap. An operating condition of the introduction means is adjusted to cause second ions, of different polarity to the first ions to be introduced into the ion trap through the same entrance aperture.

Abstract: A method of introducing ions into an ion trap and an ion storage apparatus are described. Introduction means are used to introduce first ions into an ion trap through an entrance aperture to the ion trap. An operating condition of the introduction means is adjusted to cause second ions, of different polarity to the first ions to be introduced into the ion trap through the same entrance aperture.

Abstract: An apparatus for measuring decay in intensity of electromagnetic radiation passing through a radiation-absorbent sample due to absorption of radiation by the sample is disclosed which includes a source of electromagnetic radiation having a wavelength within an absorption band of the sample and a plurality of partially-reflective specular surfaces which are spaced apart from each other along a predetermined path through the sample, each specular surface separating the incident radiation into a reflected part which follows the predetermined path and an unreflected path, the value of the decay being derived from intensity measurements of the unreflected parts made at different positions along the predetermined path.

Abstract: A quadrupole ion trapping device has a ring electrode (11) and two end-cap electrodes (12, 13). Ions are introduced into a trapping region (15) of the ion trapping device via a hole (14) in a first of the end-cap electrodes (12) and are retarded by application of a DC retarding voltage to the second of the end-cap electrodes (13). The retarding voltage is removed when the retarted ions are about to change their direction of motion towards the first end-cap electrode (12), and an ion trapping field is established by applying a radio frequency voltage to the ring electrode (11) when the ions are inside the ion trapping device.

Abstract: The apparatus comprises a sample, an optical element (4) in the form of a truncated pyramid having at least one reflective surface (1a) and a hole (7). A laser (18) directs radiation on to the sample via the reflective surface (1a) and the charged particles are extracted and directed along an extraction axis through the hole (7).