What is the primary use of the John Smith X-ray device?

The primary use of the John Smith X-ray device, as indicated in the context of this question, relates to occupational dosimetry. Occupational dosimetry involves measuring and monitoring the radiation exposure to individuals working in environments where they may be exposed to ionizing radiation, such as healthcare facilities, nuclear plants, or laboratories.

The John Smith X-ray device, designed for this purpose, likely includes features that allow for precise measurements of radiation doses accumulated by a worker over time. This information is crucial for ensuring compliance with safety regulations and for protecting workers' health by minimizing unnecessary radiation exposure. Occupational dosimetry helps in assessing risk, implementing protective measures, and maintaining safety protocols in radiation-rich environments.

In contrast, other options like medical imaging and radiation therapy pertain to different applications of X-ray technology, primarily focused on diagnosis and treatment rather than on monitoring occupational exposure. Research purposes could refer to experimental uses, but these typically do not align with the fundamental goal of dosimetry, which is to systematically track personal radiation exposure.