Stroboscopic pulse, time resolution

To address the questions of non-homogeneous/spur kinetics, John Hunt and his group at Toronto developed a sub-nanosecond pulse-radiolysis system.In their stroboscopic pulse radiolysis system, they could observe from about 30 to 350 ps after the pulse with a time resolution of about 10 ps. Their results showed no significant decay of the electron between 30 and 350 ps, which was not consistent with the diffusion-kinetic models of spur decay in radiation chemistry. 

The stroboscopic pulse radiolysis system described above was modified at Argonne National Laboratory to use a single fine-structure pulse from a 20-MeV L-band linac [150]. This reduced the uncertainty in the age of the primary produets to the width of a fine-structure pulse and allowed kinetic measurements to be extended to 3.5 ns. In practice, the time resolution of absorbance measurements was 100 ps. 

Improvements in time resolution in the stroboscopic method were achieved at the University of Tokyo by use of a twin linac system in which one aceelerator delivers the electron pulse to the sample and the other generates the Cerenkov light pulse used as the analyzing light [151]. Both linacs are driven by the same microwave source and delay between the electron pulse and the light pulse is achieved by phase shifters [151a]. The result is that the time interval between these two pulses is less than 3 ps. 

In the 1960s, Oppenheim et al. [10,19,20] succeeded in obtaining photographs with better resolution by means of schlieren technique with microsecond flash and then with the very short (less than 10 s) laser light pulses. This facilitated the attainment of a stroboscopic set of essentially still photographs that revealed many details of DDT. At the same time, Soloukhin [21] published a series of streak photographs taken with schlieren system and Denisov and Troshin [22] discovered that detonation leaves a record of its passage in the form of imprint on a wall coated with the thin layer of soot. 

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