Particles in flow cytometer irradiated by annular inspection beam and beam optics producing an annular disc inspection beam

摘要

An instrument for the analysis of particles, particularly sperm, flowing from a source 79 along a flow path 80 through an inspection zone 84, includes an optical arrangement including a source 71 of electromagnetic radiation that is directed via the prism 74 and the reflector 78 of the arrangement to converge the radiation as a substantially coplanar, radially symmetric radiation beam towards the inspection zone. The reflectors 78 and 104 collect light scattered by the particles into a beam 103 that is analyzed to determine the particle properties.