In the production of characteristic radiation at the tungsten target, what initial action takes place?

In the production of characteristic radiation at a tungsten target, the process begins when an incident electron collides with and ejects an inner-shell tungsten electron. This action is a fundamental step in the mechanism that leads to the emission of characteristic radiation.

When the high-speed incident electron approaches the tungsten atom, it has enough energy to overcome the binding energy that holds the inner-shell electron in place. The collision results in the ejection of the inner-shell electron, which leaves a vacancy in the inner shell. This vacancy creates an unstable state in the tungsten atom.

As electrons from higher energy levels (outer shells) transition down to fill this vacancy, they release energy in the form of X-rays. The energy of these X-rays corresponds to the difference in energy levels between the shells involved, which is characteristic of the tungsten element. This is why the radiation emitted is termed "characteristic radiation," as it is specific to the atomic structure of the element.

The other options do not accurately describe the initial action in this process. For instance, ejecting an outer-shell electron wouldn't lead to characteristic radiation, as this does not create a vacancy in the inner shell required for this specific type of emission. Proton absorption is not part of the X-ray production process in this