As information on REUs and internships comes into the department, it is posted online at https://apps.carleton.edu/curricular/physics/ResearchatCarleton/reu/.
Check for new information often as this site gets updated regularly. Start preparing your applications over winter break because many of these REUs have deadlines in mid January and you will want to come back to Carleton ready to submit your applications.
Please read the instructions for requesting letters of reference here http://apps.carleton.edu/curricular/physics/for_students/references/ before you ask for a letter of reference from a faculty member. This will make the process go more smoothly for everyone.