Calibration of a 137Cs γ-ray beam irradiator using large size chambers

The Air-Kerma Rate Constant: Application to Air-Kerma Measurements for Homeland Security

“…The chamber was mounted on a post made of Bakelite to minimize scattered radiation. Large-size chambers are ideal for measurement of low air-kerma rates (Minniti and Seltzer 2007). The characteristics of the chambers used are summarized in Table 2.…”

“…The airkerma rate measurement was also corrected to account for room scattered radiation. To determine the fraction of radiation scattered from the room walls, the shadow shield technique was used as described by Minniti and Seltzer (2007). The chambers were calibrated in the NIST primary reference beam facilities Minniti and Seltzer 2007) using the various beam codes available: 60 Co, 137 Cs, and highly filtered x-ray beams.…”

Development of 137Cs irradiation facility for metrological application

“…This may be attributed to the position of the chambers near the attenuator since this difference does not exceed 0.17% at 1 m for the primary beam condition. Many investigators using some models for fitting the calculated dose with distance [2] for the primary beam only not for the attenuated beam [2]. Therefore, the contribution of the scattered radiations from the attenuator affects the measurements near the source as the obtained data.…”

“…137 Cs high dose rate enforces the need of lead attenuators in order to cover the range of protection level calibrations [1]. Moreover, irradiation facilities should be characterized for use in calibration purposes and intercomparison with standard laboratories [2,11].…”

“…The major SSDLs activities used to provide traceability to customers. One of such activities is the calibration of radiation dosimeters in terms of ambient dose equivalent rate H*(10) (mSv/h) [1][2][3][4][5].…”