Butterfly Probes

It can be seen that the most probable lifetime r becomes shorter and the width of the distribution broader as the temperature is increased. For similar temperatures in liquid solution, the lifetime is unmeasurably short ( x 0.1 nsec). Therefore, r and the width of the distribution reflect the effect of the surrounding in slowing down k and not a classical activation barrier effect. 

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Fig. 8 (a) Prototype of the Magnetic Alternating Current Hyperthermia (MACH) system with a hand-held butterfly probe, (b) Pancake probe option. Courtesy of Resonant Circuits Limited, London, copyright (2011). 

Various photochemical reaction mechanisms lend themselves for variation of the above parameters, and the more important ones are summarized above. In general, one can expect for the volume necessary for the reaction to occur that it decreases in the sense Excimer > TICT > Butterfly > ESIPT mechanism. Therefore, for a given size distribution of microscopic free volume voids, the fraction of the total free volume usable for the reaction and thus amenable to probing increases in the same sense with the ESIPT mechanism being the outstanding extreme, because this reaction cannot even be stopped in a rigid matrix at very low temperature. 39 ... 

Fig. 5. Experimental equipments for matrix isolation electron spin resonance (MIESR) spectroscopy (1) catalyst (2) gas inlet (3) thermocouple well (4) pressure probe (5) metal valve (6) O-ring joints (7) gate valve (8) butterfly valve (9) two vacuum pump (10) vacuum shroud (11) sapphire rod (12) microwave cavity and (13) quadrupole mass spectrometer inlet. Reprinted from Reference 45).

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