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Regular diagnosis of the structural health of infrastructure, such as bridges, is indispensable to ensure safety and reliable operation of the society. Non-destructive tests based on X-ray imaging are powerful tools to inspect the inside of a concrete structure in detail. Establishing a diagnostic method of bridges based on X-ray visualization is required to examine the internal conditions and helps in the rationalization of maintenances. We demonstrated our 950 keV X-band electron linac based X-ray source for on-site actual bridge inspection and visualized the inner structure of a bottom floor slab. For the more precise inspection of the conditions of wires and rods, we applied three-dimensional image reconstruction methods for bridge mock-up samples. Partial angle computed tomography and tomosynthesis gave cross section images of the samples with 1 mm resolution. We are planning to investigate another part of the bridge, with the 950 keV X-ray system in the near future.

We have developed and upgraded portable 950 keV/3.95 MeV X-band (9.3 GHz) linac x-ray sources for on-site nondestructive testing (NDT) for social and industrial infrastructures. We integrated the hardware devices as well as software systems. For the hardware, we established all designed parameters including x-ray intensities of 0.05/2 Gy min−1 at 1 m for 950 keV/3.95 MeV systems, respectively. Concerning the software, we adopted the wavelet analysis for enhanced image contrast and partial angle computed tomography (CT) for a small region of interest. The wavelet analysis is effective to reduce scattered low energy x-ray noise in addition to using physical filters and collimators. The partial CT is inevitable to reconstruct an inner reinforced iron tube in concrete. We successfully performed on-site inspection three times, namely of a nitrogen acid distillation tower, a reinforced concrete pier and a large sample cut from a bridge. We obtained the x-ray images of the inner tube, determined the sizes of reinforced iron parts and evaluated the mechanical tolerance. Moreover, we are developing a new x-ray camera specified for MeV x-rays used for NDT of heavy objects. Then, our system will become a self-consisting and specialized high energy x-ray on-site inspection system. We are going to promote an application to NDT of social and industrial infrastructures in Japan and around the world.

We present Feynman- and Bjorken-variable distributions for the diffraction dissociation ( d d )π ± p →π ± (π N ) d d at 6 and 16 GeV/c. The Bjorken variable averaged over a certain (π N ) mass interval slowly decreases as the (π N ) mass increases. The magnitude of is considerably small, namelv ∼0.1 at M (π N )=1.5 GeV as compared with the value obtained in the lepton-hadron scattering. We found that the usual slope-mass correlation of dd was closely related with the mass dependence of the Bjorken variable.

The polarization for the\(\bar pp\) elastic scattering was measured as a function of the centre-of-mass angle of scattering between 17° and 90° at the average incident momentum of 0.7 GeV/c by using doublescattering events in a bubble chamber. The average value of the polarization was found to be 0.23 ± 0.05. The angular dependence of the polarization obtained in this experiment was interpreted by the strong absorptive potential model for\(\bar {\mathcal{N}}{\mathcal{N}}\) interactions recently proposed.

A study of the reaction π - p →π - π + n at 6 GeV/c incident momentum has been made using the prism plot analysis (PPA) to reject multineutral contaminations and to separate various reaction channels (ρ 0 n , f 0 n , g 0 n , π - Δ + , π - (π + n ) DD ). We can improve separability of PPA by incorporating decay angular distributions of resonances. Cross sections, invariant mass distributions, and production and decay angular distributions are presented.

We have constructed an interactive graphic system with two cathode ray tube displays which we have called the Dual Display System (DDS) for quick and efficient data analysis in high energy physics. We used the new system to analyze data from 6 GeV/c π-p inelastic reactions and found that the system could separate the reaction channels more cleanly than conventional methods and thus provide reliable information on the reaction mechanisms. This paper describes the new system and presents the software techniques for multidimensional analysis used with it.