Gatan milling systems includes Gatan dual ion-mill 600 and Gatan PIPS (Precision Ion Polishing System), which can be used to produce clean, wide viewing areas on TEM specimen and thin the specimen to electron transparency with two beams from the bottom and top surfaces of the specimen, respectively. During milling, the specimen can be rotated. For general TEM specimen preparation, Gatan PIPS, e.g. model 691, uses Ar⁺ ions to mill the specime and operates normally at 4-5 kV and ion current of 40 µA with an initial incidence angle of 6-8° and a final angle of 2-4°. Note that PIPS can also be used to clean TEM specimens after FIB- and electropolishing-preparations.

Figure 1284. Gatan PIPS (Precision Ion Polishing System).