Nuclear resonance fluorescence (NRF) supplies good information to study nuclear structure of isotopes. The main perquisite for excitation to occur, the incoming photon must have energy equal to one of the excited states of absorbing nucleus. After absorption of the photon, nucleus will have a transition to the excited state pertaining to photon energy and then the excited nucleus will decay back to the ground state by emitting a gamma ray that has energy equal to that excited state. This process is called nuclear resonance fluorescence (NRF). In this study, we estimated the optimum detector position by considering maximum photondetector interaction and counted photon amount. It can be concluded that maximum photon fluence is recorded at the under of the NRF target