What Is a Backscatter X-Ray?

In physics, backscattering is the reflection of waves, particles, or signals from the direction they came from. It is a diffuse reflection due to scattering, as opposed to a specular reflection like a mirror. Backscatter has important applications in astronomy, photography, and medical ultrasound.

In physics, backscattering is the reflection of waves, particles, or signals from the direction they came from. It is due to

Backscattering can occur in completely different physical situations, where incident waves or particles are deflected from the original direction by different mechanisms:

(1) Produced by large particles

Backscatter is the principle of radar systems.

In weather radar, if the wavelength is larger than the particle size (Rayleigh scattering), the backscatter is proportional to the 6th power of the target diameter multiplied by its inherent reflection characteristics. Water reflects almost four times more than ice, but water droplets are much smaller than snow flakes or hailstones. So backscatter depends on a mixture of these two factors. Due to their size, the strongest backscatter comes from hail and large shots (solid ice), but the non-Rayleigh (triple scattering) effect may confuse interpretations. Another comes from slush or wet rain because they combine size and water reflectivity. They often experience higher precipitation rates than what actually occurs in so-called bright bands. Rain is a moderate backscatter, with larger, larger drops (such as thunderstorms), and smaller droplets (such as fog or drizzle) being weaker. Snow has fairly weak backscatter. Dual polarization weather radars measure backscatter of horizontal and vertical polarization to infer shape information from the ratio of vertical and horizontal signals.

In fiber optic applications, backscattering is also used to detect optical faults. Light propagating through the fiber is gradually attenuated by Rayleigh scattering. The fault is therefore detected by monitoring a change in a part of the Rayleigh backscattered light. Since the backscattered light decays exponentially along the fiber optic cable, the attenuation characteristics are shown on a logarithmic scale. If the slope of the graph is steep, the power loss is high. If the slope is gentle, the fiber has satisfactory loss characteristics.

Loss measurement by the backscatter method allows fiber optic cables to be measured at one end without cutting the fiber, so it can be easily used for the construction and maintenance of optical fibers.

The term backscattering in photography means that light from a flash or flash is reflected back from particles in the field of view of the lens, causing the light to appear in the photo. This gives rise to objects sometimes called "celestial bodies". Photographic backscatter may be caused by snowflakes, rain or fog, or dust in the air. Due to the size limitation of modern compact and ultra-compact cameras, especially digital cameras, the distance between the lens and the built-in flash has been reduced, which reduces the angle of light reflection to the lens and increases the possibility of light reflection. Closes normal sub-visible Particles. Therefore, for small digital cameras or film cameras, artifacts of the object are common. ^[2]