X-ray Fluorescence angle question.

[Yondaime5685]

First of all, I'm not the one doing this experiment. I've just finished my first year in college and I'm sort of just helping all the upper-level with their research and whatnot. So my knowledge is very limited.

With that being said, one of those student is doing X-ray Fluorescence. He was just wondering if there is an "optimal" angle to which the x-ray could be pointed to get the best results.

http://upload.wikimedia.org/wikipedia/en/thumb/2/28/Dmedxrfschematic.jpg/800px-Dmedxrfschematic.jpg

Here is a pic from wiki which sort of shows the basic set up. He was thinking maybe a 120 degree angle would be good or maybe 90 degrees (Like in the picture).

Bear in mind that he didn't really ask me to do research or anything. I just wanted to find out so he didn't have to take the time to figure it out by trial and error.

Please forgive any terms I may have messed up on. If you need any more information just ask and I'll try to find out. Thanks in advance.

 

[MATLABdude]

Welcome to PhysicsForums!

Are you sure this was for X-Ray fluorescence, and not Bragg Diffraction?
http://en.wikipedia.org/wiki/Bragg_diffraction

If it is indeed Bragg diffraction, the angle is supposed to be varied. If not, unfortunately, I have nothing to add, save for the basic law of reflection: angle of incidence is the same as the angle of reflection (when measured from the normal to the reflecting surface).

 

[Yondaime5685]

^ Thanks for that. Sorry for the late reply. I was really busy this weekend.

I'll ask him about it today and will get back to you. I'm pretty sure he told me that he was doing X-Ray Fluorescence. I'm sure he knows about the basic laws of reflection. I think the question was more what angle is best so the detector "picks" up the "bounce" from the sample the "clearest". (I used quoted words since I can't think of any technical names for them. So I hope that clarifies the question more.)

Now about the Bragg Diffraction, he never mentioned it. So I'm going to assume that is not what he is doing. Nevertheless, I will ask him more about it and hopefully later on today I can get you more details.

Thanks for taking the time to reply.