Deflection and Mass Filtering

In this chapter the mass filtering systems often used in combination with cluster sources and which were developed over the last decades are discussed and compared. Deflection of nanoparticles in magnetic and electric fields is a returning theme in mass filters. The mass of the nanoparticles determines the amount of deflection which translates in a spatial change which is used to select/filter the right mass. Mass filters such as the (Reflectron) Time‐of‐flight mass filter, Quadrupole Mass Filters, Aerodynamic lenses, Wien Filter and Cluster Ion trap are discussed. Today's main challenge for mass filters is sufficient yield, which is necessary for commercial applications of mass selected nanoparticles from cluster sources. A new development in the field of matter‐wave interferometry, in which mass selected nanoparticles are used, forms a bridge to possible future developments. This chapter is concluded with a short overview of applications for mass selected nanoparticles which are currently being studied and are promising.