Terahertz Raman Measurements Using a Spatial Heterodyne Raman Spectrometer

We propose a method of measuring the terahertz (THz) Raman spectra of a material. As Raman spectroscopy is a measurement of the relative frequency spectrum relative to the frequency of the excitation source, it is not necessary to use an expensive THz source and THz detector. Instead, an ultraviolet, visible, or infrared excitation source and corresponding detector can be used. A combination of prisms and gratings is used to widen the field of view at high resolution. The resolution of the system is 4.945 cm−1 (0.149 THz), and the spectral range is 2531.84 cm−1 (75.963 THz). We measured the THz Raman spectra of solid powder, aqueous solutions, and mixtures, and studied the effects of environment, container material, and time of measurement on the spectra. The results show that the system is not significantly affected by interference from the water environment and has good stability and repeatability. This method can be applied in many fields such as material detection and environmental protection.

LINE FOLLOWING ROBOT WITH HIGH RADIATION MATERIAL DETECTION CAPABILITY

Advancement in technology have led to a rapid development in the design and manufacturing of robots, enabling them to provide human capabilities without the inherent shortcoming associated with human capabilities; such as boredom, fear, inefficiency etc. A mobile robot that can sense and observe the line drawn on the floor is the Line Follower Robot. The direction is usually predefined and can be either visible on a white surface with a high contrast colour like a black line or invisible like a magnetic field. Hence, with its Infrared Ray (IR) sensors mounted under the robot, this sort of robot can feel the line. Then, the information is conveyed by specific transition buses to the processor. The processor will determine the right commands and then send them to the driver, and the line follower robot will then follow the direction. Therefore, this paper focuses on the design of a mobile line following robot for detecting the high radiation level of a sample farmland and display on a 7-segment display by the aid of sensors to navigate through grid. The mobile line following robot must move through the squares and detect the high radiation levels and at the end provides us with information on the number of squares and detected high radiation levels. The robot's area of operation is limited to six squares each of dimension 60cm×60 cm. Silver coloured square spots with dimensions of 5 cm by 5 cm made of foil paper are used to indicate a high radiation level

Sea container inspection with tagged neutrons

Neutron inspection of sea-going cargo containers has been widely studied in the past 20 yr to non-intrusively detect terrorist threats, like explosives or Special Nuclear Materials (SNM), and illicit goods, like narcotics or smuggling materials. Fast 14 MeV neutrons are produced by a portable generator with the t(d, n)α fusion reaction, and tagged in both direction and time thanks to the alpha particle detection. This Associated Particle Technique (APT) allows focusing inspection on specific areas of interest in the containers, previously identified as containing suspicious items with X-ray radiographic scanners or radiation portal monitors. We describe the principle of APT for non-nuclear material identification, and for nuclear material detection, then we provide illustrations of the performances for 10 min inspections with significant quantities (kilograms) of explosives, illicit drugs, or SNM, in different cargo cover loads (e.g. metallic, organic, or ceramic matrices).