A remote shielded inductively coupled plasma source is used for analysis of highly radioactive samples in the Remote Analytical Laboratory at the Idaho Chemical Processing Plant, in Idaho Falls, Idaho. The shielded plasma source is located in a lead-shielded cubicle adjacent to a concrete-shielded hot cell. A passageway is provided between the hot cell and the cubicle. The cubicle contains a removable module that holds all of the functional components of the system except the induction coil. The chief components of the module are a sampling system, three-way valve, peristaltic pump, torch holder and shield, and ignitor. The radio-frequency (RF) induction coil is suspended on the end wall of the cubicle by two 5-in.-long bus bars that pass through the wall of the cubicle and connect to an impedance-matching network. The network couples the coil to a 1.5-kW, 40.68-MHz radio-frequency generator. The emission from the plasma passes outside the cubicle through a quartz window, through a lead-shielded optical system, and into a very high resolution spectrometer. Samples are diluted in the main hot cell, placed on a movable sample cart and moved through the passageway into the cubicle for analysis.
Design criteria, safety considerations, maintenance, and the operation of the facility are discussed.