Laser ion source for the MI-1309 mass spectrometer

The design of a laser ion source for a MI-1309 mass spectrometer, with the aid of which any solid specimens can be analyzed, is described. To produce ions, the laser source uses a plasma produced by subjecting the specimen to a powerful laser radiation. To form an ion beam with the required parameters, an ion-optical system is used, which consists of a conical expander, a flat grid, a flat diode, and a slot-type analyzer lens. In choosing the distance from the specimen surface to the plasma boundary, and the parameters of the flat diode, the effect of the space charge must be taken into account. The optimum accelerating voltage for the MI-1309 spectrometer is 6 kV, and the working vacuum in the source chamber is approximately 10-7 Torr. The summary ion current at the magnetic analyzer output can be as high as 10-12 - 10-11A. The mass resolution equals 100