OBJECTIVES: After completing this module you will be able to: Explain why ionizing radiation has little effect on metals and their mechanical properties. but creates significant damage in non-metals. 4.2 a) Describe the damage created in metals by fast neutrons. b) Explain how this damage affects: strength, hardness and ductility. 4.3 Explain why elevated operating temperatures reduce the effec...

Dispersion relations of longitudinal and transverse waves in two-dimensional (2D) screened-Coulomb crystals were investigated. The waves were excited in 2D crystals made from complex plasmas, i.e., dusty plasmas, by applying radiation pressure of laser light. The dependencies of the dispersion relation on the shielding parameter, the damping rate, and the wave propagation direction were experim...

We develop a new approach to the calculation of the synchrotron radiation in a toroidal vacuum chamber. Using a small parameter = √ a/R, where a is the characteristic size of the cross section of the toroid and R is the bending radius, we simplify Maxwell’s equations assuming that the characteristic frequency of the modes ω ∼ c/a , and neglecte terms of higher order in . For a rectangular cross...

We have measured the radiation transport and dose reduction properties of lunar soil with respect to selected heavy ion beams with charges and energies comparable to some components of the galactic cosmic radiation (GCR), using soil samples returned by the Apollo missions and several types of synthetic soil glasses and lunar soil simulants. The suitability for shielding studies of synthetic soi...

We carried out a questionnaire survey to determine the actual situation of radiation safety management measures in all medical institutions in Japan that had nuclear medicine facilities. The questionnaire consisted of questions concerning the evaluation of shielding capacity; radiation measurement; periodic checks of installations, equipment, and protection instruments; and the calibration of r...

In the estimation of additional shielding requirements for primary beam apart from that provided by patient and hardware in the x-ray beam, there is the need to distinguish between attenuation and hardening properties of materials in comparison. In this work, numerical comparison of attenuation and hardening properties of phantom (Lucite, soft tissue, water) and hardware (aluminum and steel) ma...

Sunset solar axions traversing the intense magnetic field of the CERN Axion Solar Telescope (CAST) experiment may be detected in a Time Projection Chamber (TPC) detector, as point-like X-rays signals. These signals could be masked, however, by the inhomogeneous background of materials in the experimental site. A detailed analysis, based on the detector characteristics, the background radiation ...

The author was the Chairman of a Task Group on the Biological Effects of Space Radiation formed as a result of discussions between NASA and the U.S. National Research Council's Committee on Space Biology and Medicine - a committee under the U.S. National Research Council's Space Studies Board. The Task Group was asked to review current knowledge on the effects of long-term exposure to radiation...