학술논문
Picosecond phase shift measurements at 358 MHz using synchrotron radiation
Document Type
Conference
Author
Source
Conference: Meeting on picosecond phenomena, Hilton Head, SC, USA, 24 May 1978
Subject
Language
English
Abstract
Properties of synchrotron radiation from SPEAR are reviewed. The power--frequency spectrum of source and photomultiplier tube is measured with a spectrum analyzer. The decay time of a single fluorescent species can be deduced by measuring the phase delay between excitation and fluorescence radiation modulated at a single suitable frequency. It is possible to characterize completely the time (impulse) response or the complex frequency response of a linear system with only phase measurements. A number of test experiments were made by using apparatus designed for time-resolved fluorescence emission anisotropy studies of tryptophan in proteins. Phase shifts were produced by insertion of water-filled quartz cells into the beam and by the introduction of a thick glass slab. The total optical path length could also be altered by linear motion of the phototube. The results yielded 4.7 +- 0.5 degrees per cm of motion. It was concluded that this procedure can be used to study short atomic and molecular fluorescence lifetimes. 3 figures. (RWR)