Performance test of SPND neutron detector and neutron flux mapping of Kartini reactor core

The performance test of the self-power neutron detector (SPND) and its utilization for neutron flux mapping of Kartini reactor core have been done. In this performance test, the measured neutron current from SPND output was calibrated by using 197Au foil activation method. The 197Au activated foil was covered by cadmium for fast neutron detection and bare 197Au foil for total neutron detection. Therefore, the neutron flux mapping can be done for thermal, fast, and total neutron flux distributions at the Kartini reactor core. The result of the test showed that the sensitivity of the SPND with 103Rh emitter is still good in performance, i.e. with measured sensitivity of SPND detector is 3.70 x 10−21 A/nv-cm. The SPND neutron detector was still performing well compared to similar neutron detector types. The following step of the test was to check the flux distribution in one channel. The fast and thermal neutron flux distribution of Kartini reactor core measured by the SPND showed good accordance with the theoretical basis, where fast neutron was higher than thermal in the central reactor core, and lower in the outer reactor core. The maximum total neutron flux is 1.95 x 1012 n/cm2s and average fast and thermal neutron fluxes at 100 kW of Kartini reactor power are 7.38 x 1011 n/cm2 s and 1.48 x 1011n/cm2 s respectively.