| 摘要 |
PURPOSE:To measure a neutron flux with high precision by controlling a compensating voltage in accordance with a gamma-ray dose rate to compensate always a gamma-ray current even if the gamma-ray dose rate is changed. CONSTITUTION:The current flowed to an ammeter 6 is I=In+Ir+Ir'. A current Ir'' 15 is flowed in the space between a gamma-ray dose rate measuring signal electrode 12 and a high voltage electrode 5. The electrode 12 is so constituted that the current Ir'' is proportional to the gamma-ray dose rate, and relations between the gamma-ray dose rate and the compensating voltage making Ir'=-Ir true is programmed preliminarily in a controller 14. Thus, the compensating voltage is applied in accordance with the gamma-ray dose rate even if the gamma-ray dose rate is changed. As the result, Ir'=-Ir is always true even if the gamma-ray dose rate is changed, and I=In is always true, and only the neutron flux is detected. |
