Etch time and the "tail" effect at various angles

Chris Dean

The animations below show etch pits made by 5.5 MeV alpha particles hitting the CR-39 surface at various angles. It was made using images from a microscope camera and MorphBuster 2.2

(Each square is 36 microns wide)

The extent to which this phenomenon affects what is seen under the microscope depends on the particle's angle of incidence and the track range. All of these etch pits are from 5.5 MeV alpha particles, which have a range of ~34 um in CR-39.

View comparisons between the fit ellipse (with the tail) and the true surface opening, with regard to: major radius minor radius circularity eccentricity