The dose from Compton backscatter screening.
Systems based on the detection of Compton backscattered X rays have been deployed for screening personnel for weapons and explosives. Similar principles are used for screening vehicles at border-crossing points. Based on well-established scattering cross sections and absorption coefficients in conjunction with reasonable estimates of the image contrast and resolution, the entrance skin dose and the dose at a depth of 1 cm can be calculated. The effective dose can be estimated using the same conversion coefficients as used to convert exposure measurements to the effective dose. It is shown that the effective dose is highly dependent on image resolution (i.e. pixel size).The effective doses for personnel screening systems are unlikely to be in compliance with the American National Standards Institute standard NS 43.17 unless the pixel sizes are >4 mm. Nevertheless, calculated effective doses are well below doses associated with health effects.
Department of Physics, Arizona State University, Tempe, AZ 85287-1504, USA. peter.rez@asu.edu
Peter
P
Rez
Robert L
RL
Metzger
Kenneth L
KL
Mossman
D006801:Humans; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000517:prevention & control*; D011834:Radiation Monitoring / Q000379:methods*; D011835:Radiation Protection / Q000379:methods*; D012015:Reference Standards; D012016:Reference Values; D012542:Scattering, Radiation; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014965:X-Rays / Q000009:adverse effects