Instrumental development for measurement of elemental distribution on swipe samples for safeguards

Yasuda, Kenichiro   ; Miyamoto, Yutaka   ; Magara, Masaaki  ; Kimura, Takaumi 

In order to estimate distribution of uranium and the other elements on the swipe samples for safeguards, we have developed a XRF scanner. The scanner is able to analyze the swipe samples which are square 10 10 cm sheets of cotton under the atmospheric condition. The scanner consists of the following components: a 50-mm Si detector with thermoelectric cooling module, a 50-W Pd X-ray tube with forced-air-cooling module and a sample changer. Compared with the detector and the X-ray tube with water-coolers, the scanner is more compact than similar instruments. The space required for this scanner is 90 cm 75 cm. The swipe sample is packed in a Ziploc plastic bag not to be spilled on the scanner. The sample fixed on a plastic frame and is measured horizontally in 280 positions. The detection limit of uranium is around 30 ng for each division when X-ray tube voltage and current are 50 kV and 1 mA, respectively.