One of the things that I had to learn upon switching fields from condensed matter to particle accelerator physics was the subject matter itself. While I had the basics of E&M, I had to learn how such things are applied in the specific area of particle accelerators and beam physics. I also had to learn the state of the field - what are known, what are being done, what are the "hot" areas, what are the major issues and problems, and what are the current demand and direction the field is going. To a lesser degree, I also had to learn some of the "names" of the important people in the field, and also try to figure out what they look like. While these things are not part of the physics curriculum in school, they are a very important part of the practice of physics. You need to know who are the big names in the field, know what they look like, because chances are, you will bump into them and may want to talk to them. This is how you make yourself known to others, especially if you're new in the field and haven't come up from the "ranks". That was my situation when I entered this field.
One of the ways I tried to learn my way around was to attend a particle accelerator school. This is a program offered at various times of the year to students interested in going into particle accelerator and beam physics. Since this program is highly specialized and not many universities offer a complete menu of the necessary courses, the particle accelerator physicists decided a long time ago to offer a series of courses that carry university credits, be it at the undergraduate or graduate level. Practically all universities accept such credits as part of the student's curriculum. So a student who wants to go into this field can spend maybe a summer taking relevant courses and have those become part of his or her academic records that his/her home university.
This program is also valuable to postdocs and others who are entering the field (such as me). There is a large variety of such particle accelerator schools within a year, and a more "general", survey type was the one I attended a few years ago. It was highly useful because I got to have an overview of the whole field, learn the "language" that was being used, got to meet many important figures in the field who volunteered to be the instructors in the various courses (example: Tom Wangler, who wrote the definitive book in RF linear accelerator, was teaching that course using his book), and generally managed to get acquainted with people in the field. This was highly valuable because since then, I've had a few collaborations with the people I made contact with at this particle accelerator school.
The particle accelerator school in the US is offered several times throughout the year, and especially over the summer months. There are also particle accelerator schools being offered in Japan, Europe, and Russia. in fact, there have been several joint US-Japan-Europe-Russia particle accelerator schools being offered at various parts of the world.
If you are intersted in attending one of these, talk to your academic advisor/supervisor and look at the courses being offered at
There are also links to other particle accelerator schools and programs being offered throughout the world.