Control system for a deuterium-tritium mixture in liquid phase produced by from a cryogenic distillation column - SOLDDT

Finance Agreement no 71-064/2007

   The project objective is to develop a control system for deuterium-tritium composition mixture in liquide phase, produced by a cryogenic distillation column. The solution proposed is based on the measurement of the complex permitivity (relative permitivity and electric conductivity) of the above-mentioned mixture, by means of a capacitive sensor.
   During the first stage, we proceed to determining the deuterium concentration of the hydrogen-deuterium mixtures in liquid phase and start with the elaboration of mathematical models on the dielectric behaviour of this fluid.
   The development of the capacitive sensor will comply with the requirements of the cryogenic distillation column of the ITER installation, for preliminary tests to Forschungszentrum Karlsruhe in the same conditions like ITER. Using a test stand of a cyostat with built-in sensor, will determine the transducer coefficient in vacuum, gas and liquid conditions fully charged (hydrogen and deuterium) in stationary regime with the view of minimising the parasite capacities that may influence the sensitivity. We will also conduct experiments in stationary regime in order to determine the deuterium of H-D mixtures in liquid phase, at temperatures ranging between 20 and 25K and in various mixture compositions.
   During the next stage, the experimental stand will be modified so that to admit tests of sensor performances in fluid regime. The experiments being performed using various H-D mixture compositions, different flows rates and at temperatures ranging between 20 and 25K. The results will be then matched with the measurements made using the Finnigan Delta Plus mass spectrometer and will serve as the basis for the corrections required by the established mathematical model.
   The measurement system will take into account the measurement accuracy (<5%), as well as the adverse effect of the heterogeneous electric field and of the complex permitivity between the hydrogen and deuterium in liquid state. Taking into account the imposed requirements, we will use the method of measurement at the resonance frequency, the electronic module being designed and build in this purpose. A software package will include the established mathematical model and the experimental results so that the mixture composition is clearly determined.
   During the next stage, we will draft the technical specifications for the control system with the pupose of operating a cryogenic column used for producing D-T mixtures of concentrations higher than 95%, as well as a fesability study on its implementation in the ITER Cryogenic Distillation Installation.
   The project set up contains a major component regarding the results disemination and the proposed methodology with an originally authentic content, opens new research directions in this field.
   The determination method of the H-D mixture composition will be patented. International institutes have expressed their interest in the project results adn, also, the FP7 programme provides a task in the field of the project.