Particle distribution measurements using in line Fraunhofer holography

In-line Fraunhofer holography has been developed and implemented at Los Alamos National Laboratory to measure particle distributions of fast moving particles. Holography is a unique diagnostic that gives unambiguous information on the size and shapes of particle distributions over a three dimensional volume. Currently, the capability of measuring particles two microns in size which travel many mm/{mu}sec has been demonstrated in hydrodynamic experiments at the Pegasus Pulsed Power Facility. Normally, for setting up an in- line holography experiment for measuring particles a few microns in size, the holographic film would be placed less than one centimeter from the particles. However, due to the high energy associated with the dynamic experiment, an optical relay system is used to relay the interference pattern 35 cm so that glass hologram will survive. After the hologram has been made the data must be extracted. This is accomplished by using a laser to reconstruct the data in space. This three dimensional image is then digitized via a CCD camera and a three axis actuator system. After the data has been digitized it is then analyzed with intelligent image processing algorithms. Details will be described below.