Radiant energy reradiating flow cell system and method

Abstract

In an apparatus in which particles which may include biological cells are passed through an optical sensing zone to measure their spatial radiant energy distribution for the purpose of identifying and/or characterizing the particles or cells, a structure and method are provided for increasing the usefulness of a geometric configuration of photovoltaic detectors such as a known assembly of generally concentric rings of such detectors usually including some wedge-shaped detectors. These are provided in a generally planar form and the invention provides structure which captures radiant energy in a flow cell of a particular type before projecting the energy to the detector. In particular an ellipsoid, paraboloid, hyperboloid or similar reflector which is symmetrical about its optical axis is utilized first to capture the radiant energy on angles which could include most forward and/or backward angles and all azimuthal angles and then deviating the same to the detector assembly mentioned. By moving the arrangement or assembly of detectors along the optical axis of the reflector the optimum distance is established for obtaining the greatest amount of information sought. Although the assembly of photovoltaic detectors may thereafter be left in place, it is preferred to substitute for said assembly a second highly economical deviating or reflecting device capable of capturing the radiant energy which would otherwise have fallen on the sensitive plane of the assembly of photovoltaic detectors and deviating the same along a plurality of different spaced paths to independent photodetecting devices.