Extended study for performances of beam quality indicator

The performance of the beam quality indicator (BQI) was studied for confirmation of its reliability. An original BQI (named “BQI.org”) and five newly designed BQIs (named “BQI.001–BQI.005”) were compared with a variety of imaging systems with different beam spectra. With the best quality of a BQI image obtained, the data was carefully analyzed, and ±1% precision was expected. However, a ±7% systematic uncertainty was observed for imaging systems, including a difference of BQIs. Spectra of attenuation coefficients were measured using a TOF method for Pb and Ti, which was used to define a calibration curve for the BQIs. The curve will be compared with the previously defined calibration curve for the BQI.org.