Search

The dense granular flow spallation target is a new target concept proposed for an Accelerator-Driven Sub-critical (ADS) system. In this paper, the beam-target configurations of a tungsten granular flow target for the ADS with a thermal power of 1 GW is explored. The beam profile options using different scanning methods are discussed. The critical geometry parameters are adjusted to investigate the performance of the granular target from the aspects of neutron efficiency, stability and temperature distribution in target medium. To figure out how the target under accident conditions would behave, different clogging conditions are induced in the simulation. The dynamic processes are analyzed and some important parameters such as abnormal temperature rise and beam cutoff time window are obtained. The response of the sub-critical reactor to a clogging accident is also investigated. It is indicated that the monitoring of the granular flow by the neutron detectors in the sub-critical core will be effective.

A granular flow target coupled with a beam window was studied. The beam window isolates the accelerator from the target, making the system more secure and flexible. Preliminary analyses for the beam window and beam tube, including neutronics, thermal hydraulics, and structural mechanics were performed by Geant4 and ANSYS. The effects of geometry and coolant flow direction on the temperature field and the stress distribution of the beam window are studied. The results show that the maximum temperature can be reduced by 13% through optimization. Comparing the thermal deposition distribution of the beam tube with and without the beam window, we find that there is an extra peak due to the beam window. In addition, the effect of the cooling pattern on the temperature distribution of the beam tube is also studied. The results show that it is reasonable to arrange six U-shaped cooling channels. Detailed analyses show that the material temperature and the mechanical property of the beam window and beam tube meet the design standards, which confirm the possibility of granular flow target with a beam window for engineering application. [ABSTRACT FROM AUTHOR]

The Compact Materials Irradiation Facility (CMIF) project will provide a high-energy, high-flux neutron source for material irradiation research which will be indispensable for the long-term Accelerator-Driven Advanced Nuclear Energy (ADANE) project in China. CMIF is a Be(d, xn) neutron source driven by a 10 mA @ 50 MeV continuous wave (CW) deuteron beam with a granular flow target. This paper presents numerical studies of a granular beryllium target which adopts inclined granular flow to serve as both the target body and also the heat carrier. First of all, the flow constancy of the chute flow is investigated. Next the relationship between the irradiation conditions and the beam-target parameters is studied. To investigate the heat processing ability of this kind of target, the heat deposition and transfer in the target are simulated numerically. Finally, the heat removal for the backplate and also irradiation damage are investigated. [ABSTRACT FROM AUTHOR]