Final answer:
A Conical Beam is created using a convex lens, where a light source is placed at its focal point resulting in parallel light rays on the opposite side. This is used for creating directional beams of light, and in medicine, a similar principle is used for concentrating radiation in tumor treatment.
Step-by-step explanation:
The proper technique to perform a Conical Beam involves using a convex lens and placing a small light source at its focal point. According to physical principles, when a light source is positioned at the focal point of a convex lens, the rays of light that emerge on the other side will be parallel. This is because the diverging light rays from the source are refracted by the convex lens and leave the lens as a collimated beam of light, which is useful for producing a directional beam of light commonly used in applications such as lighthouses and traffic lights.
When applying this concept to medical radiation techniques, such as those used in cancer treatment, a narrow beam of radiation, similar to the conical beam of light, is directed at the patient from various angles with a common intersection point in the tumor. This geometric technique allows for a concentration of the radiation dose in the tumor while minimizing exposure to surrounding healthy tissue, enhancing the therapeutic ratio.