A mass spectrometer system includes an inlet system having an aerodynamic lens system for collimating charged particles into a beam, and an aerodynamic kinetic energy reducing device for receiving and slowing the charged particles to near zero kinetic energy. A detection system receives and identifies a mass of the charged particles. The aerodynamic kinetic energy reducing device can be a reverse jet or a pathway through a stagnant volume of gas. Such mass spectrometer systems can operate in a mass range from 1 to 10.sup.16 DA.