What am I actually supposed to say when asking about PhD's?

[jeebs]

I'm a physics undergraduate (currently masters year right now) in the UK and I want to keep on doing physics. I'm thinking of trying to get onto either a fusion or a particle physics type of course (is this a wise choice by the way? I get the impression a lot of physics graduates do PhD's in condensed matter physics for the most opportunities, but that area of physics doesn't exactly thrill me), and apparently I'm supposed to email the people who are in charge of which ever course it is.
I'm really not sure what I'm supposed to say though, I can't just say "Hi, I want to do this course..."
How do I go about this first step properly?

Thanks.

 

[The_Duck]

Does "course" mean "physics department at a school"? I'm not exactly clear on UK terminology. I'd do a bunch of reading online--department websites, papers, and such--and try and find a field or some research groups that you'd be really excited about working in. Then to learn more about it, what I've done is emailed professors doing what I'd like to do, and asked to get in touch with their graduate students. Then asked the graduate students what it's like to work in the field, how they got into it, whether it seems very competitive, and so on.