Study on beam behavior in beam transport line for accelerator driven system

Accelerator Driven System (ADS) has the inherent transient that the beam behavior change affects the core performance. Such beam variation is called "beam transient", and it was reported that beam transient has a possibility to cause core damage. This study is intended to examine the beam behavior in an ADS beam transport line. The beam transport calculation code TRACE 3-D is selected for the beam behavior analysis, and the applicability of TRACE 3-D to ADS beam transport line is verified by comparing with the operating data obtained in J-PARC. TRACE 3-D calculations are performed on the basis of measured data in the verification, and the calculation results agree with it well. The beam behavior in the ADS beam transport line is analyzed with respect to the presence of various changes such as the deviations at the entry of the line and the alignment error of quadrupole magnets in the line. The calculation results reveal that the large deviations of the beam centroid positions are possible at the target surface, and it can lead to the core damage as compared with the past core analyses. (author)