Current-to-flux experimental results in the YALINA-Booster subcritical assembly

As a part of the IP-EUROTRANS experimental program at YALINA-Booster, presented in this conference, a set of measurements concerning the current-to-flux techniques has been performed. In a subcritical assembly coupled to an accelerator operating in continuous mode, the power of the reactor is related to the accelerator beam current and the external neutron source strength. It is generally assumed that by monitoring the ratio between the accelerator beam current and the neutron source intensity as well as the ratio between the neutron source intensity and the core power, any change in the system can be detected. With this methodology, changes in the system caused by reactivity transients can be isolated. However, it has been observed that this is only true for transients in the time scale of seconds. At CIEMAT, an acquisition system capable of monitoring the core power, the accelerator beam current and the neutron source intensity in the millisecond scale has been developed. It has been observed that, in these short time ranges, the proportionality relationship between these three quantities is not always fulfilled.
QC 20140929