Experimental Findings on Kinetics

One of the basic requirements is to synthesize the desirable compounds and to rapidly transport them to the equipment for chemical experiments. The time spent to accomplish such processes and its probability distribution can be properly determined only when a radioisotope of the element under study can be produced in a quantity that can be easily and accurately measured. It has never been the case for the transactinoid elements. Rough estimation of the chlorination time of Zr and Mo was done in the model experiments described in the above Section (see also Fig. 1.2). The ampoule was filled with pure inert gas, then closed and bombarded for some time with neutrons at ambient temperature. Thus, the thermalized fission products were accumulated on the walls. Then the ampoule was heated and flushed for a short time with the gas containing a reagent. Most of the activity got transferred into the nap in 30 seconds or so it involved a mean gas hold-up time of 15 seconds, so that the actual upper limit of the chlorination time could be set as 15 seconds. 

Reproduced (adapted) from Radiokhimiya, 9(2), Zvara I, Zvarova TS, Caletka R, Chuburkov YuT, Shalaevskii MR, Express continuous separation of transition elements of groups III and IV, 231-239, 1967, with permission from Academizdatcenter Nauka Publishers. 

In the first experiments ZrCU was one of the chlorinating agents. It was expected to be a nearly isotopic carrier, not only for HfCU, but also for RICI4. In the first 

3 Production of Transactinoid Elements, Synthesis and Transportation of Compounds 

The described techniques with blinking accelerator beam are quite cumbersome. Of course, mere observation that a short-lived radionuclide appears at the exit of the column indicates that the retention time is of similar order as the half-life. However, more precise measurements would require an independent determination of the initial activity released from the target. In the case of short-lived nuclides, the traditional simple catcher experiments can again be realized only by repeated bombardments and with the use of some technical tools. 

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