Detection of a gas region in a human body across a therapeutic carbon beam by measuring low-energy photons

We studied feasibility of detection of a gap which is located across a beam track by measuring low-energy (63–68 keV) photons generated by beam irradiation. An experiment was performed with the Heavy Ion Medical Accelerator in Chiba (HIMAC). A 12C beam having 290 MeV/u was injected on a target consisting of two acrylic blocks. These two blocks were placed with a 10 mm gap along the beam axis. A detection system consisting of a semiconductor detector, a lead collimator having a slit, and borated polyethylene blocks was placed on a movable stage to detect low-energy photons emitted perpendicularly to the beam axis. The position of the detection system was moved at 2 mm intervals along the beam axis. It was found that the yield of 63–68 keV photons was clearly correlated with the position of the detection system. The position at which the yield curve had the lowest value agreed with the gap position. We also confirmed that the experimental result was well reproduced by a Monte Carlo simulation that includes generation of secondary electron bremsstrahlung.

Study on Mechanical Properties and Field Monitoring of Ballastless CWR on the Bridge in High-Speed Railway

In the design of long-span bridge , it is necessary to lay the expansion regulator in order to reduce the beam-track interaction. Take the Zhengzhou-Xi’an high-speed railway as an example, the paper created a CWR mechanical model on the bridge using the finite element software ANSYS, proposed the deformation law of the structure and its stress characteristics. Based on the fiber grating testing technology, many monitoring points were laid on the Weihe bridge, to make a long-term monitoring. Processed the monitoring data about rail temperature and temperature force of the regulator, the CWR service conditions were assessed. The study shows that the scheme laying a set of regulator on the longest span Weihe bridge has greatly decreased the beam-rail interaction. All of its design parameters are reasonable. The operation safety indexes can completely meet the need of limits.

Pendair—A Proposed Lower Cost Rapid Transit System Compatible with the Urban Environment

Increasing traffic congestion and the possible oil shortages make it desirable to introduce segregated electrically driven rapid transit on a much wider scale than is likely to be achieved by the conventional underground metropolitan railway. The characteristics of rapid transit are examined. It is concluded that new techniques should be developed to supplement existing methods by exploiting the overhead solution to the problem of restricted ground space in urban areas. The Pendair mass transit system is based on a suction air suspension and a concrete beam track. Their favourable interaction leads to a relatively low cost system with some desirable performance, safety and environmental features which are described.