抄録
Growth of anthracene single crystals from melt by Bridgman method is described. The crystals are grown to a shape of a cylinder, about 2.5cm in both diameter and height, to be used for a scintillator.
For designing the furnace, growth velocity, temperature, and rate of cooling of the crystal after solidification are obtained by calculation. Temperature of the furnace around the tube in which the crystal is grown is controlled enabling it to be maintained within ±0.03°C of fluctuation for several days. The tube has four small windows at solid-liquid interface level, through which the growth of crystal is watched. Removing the crystal from the tube is effective in avoid-ing the cracking in cooling. Growing of crystals from prepared seeds has been successful; good crystals grown in (001) direction can be made from seed. Crystals that originate spontaneously are apt to grow along (010) direction; they are not suited for the purpose.
For the examination of scintillation characteristics of the grown crystals, scintillation spectra for radiations from Co60, Sr90, Cs187 and S35 are measured with satisfactory results.
