Application of holography to bubble chambers- a review

The use of holography to provide adequate focal depth is discussed, together with the appearance of track images reconstructed from image holograms of simulated bubble tracks whose small angle scattering function closely matches that of bubbles in liquid hydrogen. A brief description of the problems of bubble chamber optics is given, stressing the need to illuminate the chamber using Scotchlite on future large chambers. Experimental measurements of the contrast and widths of reconstructed track images are reported. Tolerances on the reference and reconstruction beam geometries and film flatness are given in relation to the measurement of bubble image positions to ± 1 μm in the hologram space. The formation of an image hologram minimises these tolerances and also permits the reconstruction stage to be carried out using a polychromatic extended source which could be useful for visual scanning of the track images.