Standard method for measurement of bulk etch in CR-39

An accurate, consistent and convenient method for the measurement of the bulk etch is essential in the calibration of any track detector. It is an especially important parameter for CR-39 in particular, since the predominantly measured parameters are the track opening dimensions. Of several bulk etch techniques available, many groups use the method employing the measurement of track diameters of fission fragments. The limitations and difficulties of this system are discussed and the more accurate method of using the sample mass change is proposed, especially when more than about 15 μm of detector surface is removed. (author)