Intensified Ultraviolet Analyzing Lamp for Flash Photolysis

Abstract

An intensifier is described which increases the light level of an Osram 150 W xenon lamp by a factor of up to 30 at 350 nm, and holds it constant to 0.02% of the brightened level for 10 msec. Control for longer times is possible. This precision of control is possible only when the light level seen by a photomultiplier is used to regulate the intensified level. If two photomultipliers are used, one to observe the transient absorption signals and the other to control the light level, then the light level can be held constant to about 0.1%. This limitation is not due to the intensifier circuit, but to the difficulty of optically matching two beams and two photomultipliers.