723 



Edgar Inselberg and J. L. Rosenberg 



osci I loscope 



Fig. $, Experimental arrangement for resolving the 

 contribution of luminescence and absorption changes 

 to fast changes in li^t intensity. Lenses, filters, 

 and baffles are not shown. 



angle to the monochromatic beam, detects changes in emission su- 

 perimposed on the flash-only waveform, while the waveform of P-, 

 consists of three components, the absorption change, the emission 

 change, and the flash intensity. The two waveforms are displayed 

 simultaneously on the screen of a multichannel oscilloscope, 

 w^iile the absorption change is the difference waveform obtained 

 directly by connecting the output of the two phototubes to a bal- 

 anced oscilloscope input. A more precise estimate of the absorp- 

 tion change is obtained by placing identical interference fil- 

 ters, corresponding in transmission to the monocliroraatic beam, in 

 front of P-j^ and ?2* ^2 ^^^ also be used for studying the nature 

 of the flash-induced luminescence by locating a monochromator 



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