Don't bother to include your report. No one will read it, and some people will be annoyed that you made the package longer than necessary (think about being the admissions secretary with 700 applications on your desk, that you need to whittle down to a 200 application 'short list' which actually gets read. It's really easy to throw out the one that's way too long).
What you should do is submit the paper to a real journal (like the physical review), get it published, then add a section to your CV for your publications, and list the paper there. This assumes that your work constitutes a novel contribution to your field. If not, you should make a novel contribution to your field, and publish a paper about it, and put that on your CV.
Summary: publish actual stuff and don't make your application fit the TLDNR (too long did not read) category.