ABSTRACT
An apparatus is designed for use in obtaining fluorescence spectra, excitation spectra, and delayed fluorescence spectra, usually at low temperatures. A photometrically regulated 6500-W xenon lamp is used as excitation source, a double monochromator or varioilluminator as excitation monochromator; a variable temperature liquid helium cryostat as specimen holder; a double grating monochromator or varioilluminator as detection monochromator; and a photomultiplier as detector. A quartz-iodine lamp calibrated against a standard tungsten-quartz lamp is used for intensity calibrations. Fluorescence spectra are recorded by a digital system with a shaft position encoder for digitizing wavelength and an analog-to-digital converter for intensity. Data are recorded on magnetic tape which can be processed directly by an IBM system 360 computer. The selection of components of adequate resolution, speed, and capacity is discussed, and the computer programs are described. Installation of the recording system 1ms facilitated greater wavelength accuracy and long calculations on the experimental data. Examples are given.