DEVELOPMENT OF CONTROL SYSTEM FOR THE FLOW RATE/PASSAGE OF TRITIUM WITH BREMSSTRAHLUNG COUNTING METHOD.

As a first step, to improve the sensitivity of bremsstrahlung counting method, the effect of a gold evaporated window on the intensity of bremsstrahlung X-rays has been examined. The window plays important roles of the confinement of tritium and the emission of the bremsstrahlung X-rays. By using the gold coating window, it was seen that the detection limit was extended toward lower tritium concentration of about 0.1 muCi/cm^3. In addition to the above examination, some preliminary experiments were carried out using an apparatus constructed to test the applicability of bremsstrahlung counting method to the control system. As a result, it was seen from the preliminary tests that two control valves attached to the present apparatus precisely operated at a given concentration irrespective to the flow rate in the range from 7 to 54 cm^3/min. From those results, it was revealed that it was possible to develop a tritium control system based on the bremsstrahlung counting method.