Question

The increased brightness as visualized at the output phosphor is due to:

1. flux gain
2. minification gain
3. smaller size of the output phosphor
4. additional energy of the electrons as they were accelerated through the image intensifier

Answer 1

Increased brightness at the output phosphor in an imaging system is mainly due to flux gain and minification gain, which amplify the photon output and concentrate the image brightness, respectively.

Step-by-step explanation:

The question is about the factors contributing to the increased brightness at the output phosphor in an imaging system, such as an image intensifier used in fluoroscopy.

The increase in brightness seen is primarily due to two factors: flux gain and minification gain. Flux gain refers to the multiplication of light photons due to the acceleration of electrons within the device, which is achieved by the impact of the electrons on the output phosphor, releasing more photons than initially entered.

Minification gain is the increase in brightness achieved by focusing the image from a larger input screen to a smaller output screen, thus concentrating the light into a smaller area and increasing the brightness of the image.