Three other major technological initiatives were taken. Filters of (large, perfect) single-crystals (quartz), preferably cooled to low temperatures, enabled major improvement in the ratio of slow neutrons to fast in the primary beam and thus in the signal to background ratio. The "Beryllium Detector" method was developed by enabling the Triple-Axis spectrometer to accept Beryllium polycrystalline filters in the scattered beam and thus, with incoming neutrons of variable energy, to get energy distributions in a different and sometimes advantageous manner - an inverse of the Filter-Chopper method. Finally profitable uses of the new material, pyrolitic graphite, were found - as filters and as crude monochromators.