Search results for "Electrostatic lens"
showing 2 items of 2 documents
The squeezer ion guide
1992
Abstract The properties of an ordinary ion guide can be improved by inserting a grid between the nozzle and the skimmer. When positive ions are transported, an electric potential lower than +10 V is connected to the grid and one of the order of − 10 V to the skimmer. Efficient focusing is achieved between the nozzle and the grid by a combined action of the viscous helium flow field and the weak electric field. The focusing device is called a “squeezer”. It can be extended by adding more grids, a second skimmer, and differential pumping. Contrary to the first grid, the additional elements act more or less like electrostatic lenses in medium vacuum. With the squeezer ion guide, ions created i…
A combination intermediate-image magnetic plus Si(Li) electron spectrometer for in-beam experiments
1979
Abstract A magnetic lens plus Si(Li) combination in-beam beta spectrometer with focusing properties and field shape similar to those of an intermediate-image spectrometer is described. A high transmission and a large momentum band-width are achieved by placing both the target and the detector in a high magnetic field inside the lens. The beam enters the lens axially, and the Faraday cup is placed inside the lens. The spectrometer is well suited to singles conversion-electron spectroscopy, to electron-heavy particle coincidence measurements, to lifetime measurements and to studies of internal-pair transitions.