Evaluation of the calibration factors of neutron dose rate meters in a ~(241)Am–Be neutron field

Calibrations were performed for three types of neutron ambient dose equivalent rate meters, i.e., Aloka TPS-451C (Hitachi), KSAR1 U.06(Baltic Scientific Instruments), and Model 12-4(Ludlum), using a standard field of a ~(241) Am–Be source. The measured total neutron ambient dose equivalent rates, H*(10)'_( tot), were analyzed to obtain the direct neutron ambient dose equivalent rates,H*(10)'_(dir), using the ISO 8529-2-recommended generalized-fit method, semiempirical fit method, and reducedfitting method(RFM) fit methods. The calibration factor(CF), defined as the ratio between the conventional true value of the neutron ambient dose equivalent rates in a free field, H*(10)'_(FF), and H*(10)'_(dir), was evaluated as one of the important characteristics of the neutron meters in the present work. The fitting results show that the H*(10)'_(dir) values of the meters are in good agreement within the theoretical data within 4%. The averaged CFs of the three neutron meters were evaluated as 0:99±0:01, 1:00±0:03; and0:99±0:08, respectively. The largest standard uncertainty of these values was determined to be approximately18.47%(k=1). The standard uncertainty of the CFs obtained using the RFM method was less than 4.23%(k=1), which is the smallest uncertainty among the three methods.

Radiotherapy-customized head immobilization masks: from modeling and analysis to 3D printing

Nuclear Science and Techniques - Calibrations were performed for three types of neutron ambient dose equivalent rate meters, i.e., Aloka TPS-451C (Hitachi), KSAR1U.06 (Baltic Scientific...