Abstract: A particle-optical apparatus comprising a sample holder for receiving a sample, a particle source embodied to produce a primary beam of first electrically charged particles along an optical axis for the purpose of irradiating the sample, first detector embodied to detect second electrically charged particles that emanate from the sample as a result of the irradiation thereof, a Detection space that at the least is formed by the sample holder and the first detector, and an immersion lens embodied to produce a magnetic field for the purpose of focusing the primary beam in the vicinity of the sample holder. The first detector are embodied to produce an electric field in the detection space, and the detection space is embodied to comprise a gas.

Abstract: A steel propellant casing includes a substantially cylindrical casing body provided with a casing bottom at one end thereof and with a shoulder cone at an opposite end thereof. The shoulder cone terminates in a casing neck, and has an essentially uniform wall thickness. The shoulder cone wall thickness is, within a range of up to several tenths of a millimeter, less than the wall thickness of the casing body adjacent the shoulder cone between the shoulder cone and the casing bottom.