A System has been developed to make rapid automated measurements of isotopic ratios from many individual micrometer-sized particles dispersed on a substrate. High particle throughput is achieved by using a commercial secondary ion microscope to collect direct ion images simultaneously from multiple particles within the field-of-view of the microscope. Isotopic image pairs are recorded by spatially resolved single ion counting with a resistive anode encoder (RAE) image detector. After the image pairs are stored in computer memory, the sample stage is automatically moved to an adjacent area and the recording process is repeated, so that many image fields can be sampled without operator intervention. Pairs of isotopic images are processed to define particles within images and to calculate individual isotopic ratios. Using this system, we have been able to make isotopic measurements on more than 1000 particles in a single working day.
Citation: Secondary Ion Mass Spectrometry SIMS XI
Publisher Info: Wiley, Hoboken, NJ
Pub Type: Books
isotopic ratio, particle, SIMS, uranium