Production of the bremsstrahlung

[nousername]

Hey,

My book says: When an electron strikes the target metal it is attracted by the positively charged nuclei, and hence it loses speed and hence emits a photon of X-ray.

That doesn't make sense to me. We learned that in centripitel acceleration, that the speed of the object being centripitally accelerated stays the same, and this is the case with this.. the electron is being centripitally accelerated by the nuclei and hence it shouldn't loose speed. Can someone explain to me why it loses speed?

BTW: I know this isn't a homework or coursework question, but one of the people kept on moving my previous questions which i posted under the general physics forum... SO DONT MOVE THIS ONE OR OTHERWISE COME TO A CONCLUSION AS TO WHAT IS COURSEWORK QUESTIONS AND WHAT IS GENERAL PHYSICS! THIS QUESTION WASNT ASKED AS HOMEWORK! IM JUST WONDERING! BUT MY PREVIOUS TWO QUESTIONS GOT MOVED!

 

[lightgrav]

the impinging electron collides with an inner-shell atomic electron, and transfers a lot of its momentum (even ionizing the atom by ejecting it). This vigorous acceleration is accompanied by Brems radiation (Electric fields and magnetic fields change rapidly).
The "spikes" in the x-ray spectrum comes from the "cascade" as outer-shell electrons fall inward, to fill in the vacancy where the ejected one used to be.