Need experts on senior loan investments.

I’m looking for advisors, market analysts and academics with views on the pros and cons of investing in senior loans. First, I’d like an explanation in layman’s terms of just what these are, how they work, how big the market is and so forth. Next, who is the ideal investor for senior loans, and who should stay away? Are the best for income, or are there capital gains as well? Best for those in and near retirement, of for younger investors also? Would you consider these suitable for the safer end of the portfolio, or the riskier side? Next, what features should the investor look for, positive and
negative? How do you asses risks? What kinds of yields and returns can investors expect today? How do these perform when the economy is getting stronger and interest rates are likely to rise? Finally, what’s the best way for a small investor to get into these? One expert recommended closed-end funds? Do you agree? Can you recommend any products in particular? Requirements: I prefer responses by email containing usable content and quotes, and because I usually get plenty I rarely respond to ones merely offering a source for interview.