Question

To detect bombs that may be smuggled onto airplanes, the Federal Aviation Administration (FAA) will soon require all major airports in the United States to install thermal neutron analyzers. The thermal neutron analyzer will bombard baggage with low-energy neutrons, converting some of the nitrogen- 14 nuclei to nitrogen- \(15,\) with simultaneous emission of \(\gamma\) rays. Because nitrogen content is usually high in explosives, detection of a high dosage of \(\gamma\) rays will suggest that a bomb may be present. (a) Write an equation for the nuclear process. (b) Compare this technique with the conventional X-ray detection method.

Short answer

The nuclear process can be represented as: \[{}^{14}_7N + {}^1_0n \rightarrow {}^{15}_7N + \gamma\]. The traditional X-ray detection method scans for shape and density of objects, while the thermal neutron analyzer method detects the high nitrogen content present in many explosives by observing gamma rays released in the nuclear reaction. Thus, the thermal neutron analyzer method is potentially more effective in detecting explosives compared to the traditional method.

Step-by-step solution

Understand the nuclear process

When the baggage is bombarded with low-energy neutrons, some of the nitrogen-14 (N-14) nuclei are converted to nitrogen-15 (N-15), with simultaneous emission of \(\gamma\) rays. This conversion process, also known as nuclear transmutation, can be written in the following equation: \[{}^{14}_7N + {}^1_0n \rightarrow {}^{15}_7N + \gamma\] Here, \( \gamma \) represents the gamma rays.

Understand the conventional X-ray detection method

In the conventional X-ray detection method, X-rays are used to scan the baggage. It involves the use of X-ray imaging to detect potentially harmful objects. When X-rays pass through the baggage, the objects inside absorb different amounts of X-rays based on their density and composition, creating an image on the detector. The operator can then analyze the generated images to identify any suspicious objects.

Compare the thermal neutron analyzer with the conventional X-ray detection method

The conventional X-ray detection method primarily focuses on the density and shape of the objects inside the baggage, and may therefore miss detecting explosives that do not significantly differ in these properties. However, with the thermal neutron analyzer method, the focus is on the detection of high nitrogen content, which is a typical characteristic of many explosives. Therefore, explosives can be more effectively detected using this nuclear transmutation-based method. In addition, the thermal neutron analyzer method, by detecting the emission of gamma rays, can provide information about the presence of certain specific materials, not just their shape and density.