Computation of neutron radiation dose on fills near KEK-PS EP1 beam extraction line

In order to investigate if GEANT program was effective for computation on neutron dose formed by an accelerator, a simulation was carried out. Here was compared computing results with experimental data by using the program for neutron radiation dose on a fill near EP1 beam extraction line in the KEK 12-GeV Proton Synchrotron (a case of slow beam extraction). Then, some results tested on leaked neutron dose at the fill near extraction line when slow beam extraction of EP1 at the Proton Synchrotron were used for experimental data for their comparison. As a result, it was found that the dose was higher at down-stream (forward direction area) of position laid by a septum and that the dose at an area from side to rear directions of the fill was lower by one to two orders than the dose at front direction. And, results on its simulation showed that dose distribution was almost symmetric at a boundary of the side direction, and that the dose at the front direction was near the tested values, but those at the side and rear directions were higher. (G.K.)