Total field, scatt field, incident field

[fisico30]

total field, scatt field, incident field...

in scattering problems, there is this formulation

total field= incident+ scattered

But once a scatterer is hit by an incident field, it re-emits, re-radiates in different directions.
Why should the field at a particular place always have to be the sum of the scattered and the incident? maybe the incident is not there?

We are like assuming that the incident field moves across the scatterer as if the object was not there. Then the scattered field modifies the incident field to get the total field...

Behind the scatterer, I would, for instance just see scattered field...

 

[Almsco]

Yes, that is correct. When the incident field is not present, the total field is only composed of the scattered field. The incident field only adds to the total field when it is present.

 

[charng]

I would like to clarify that the total field, scattered field, and incident field are all important components in understanding scattering problems. The total field is the sum of the incident and scattered fields, and it represents the overall electromagnetic field at a particular point in space. The incident field is the initial electromagnetic field that is directed towards the scatterer. The scattered field is the electromagnetic field that is produced by the scatterer as a result of the incident field.

It is important to keep in mind that the total field is not simply the sum of the incident and scattered fields, but rather a combination of the two that takes into account the interaction between them. This is because the scatterer modifies the incident field as it re-emits and re-radiates in different directions.

It is also important to note that the incident field may not always be present or may not always have a significant effect on the total field. In certain cases, the scatterer may be large enough or the incident field may be weak enough that the scattered field dominates and the incident field can be neglected. However, it is still important to consider the incident field in the overall understanding of the scattering problem.

In conclusion, the total field, scattered field, and incident field are all crucial components in understanding scattering problems and should not be disregarded. The interaction between these fields is what ultimately determines the behavior of the electromagnetic field in the presence of a scatterer.